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Tundo, Pietro, Paul Anastas, David StC Black, Joseph Breen, Terrence J. Collins, Sofia Memoli, Junshi Miyamoto, Martyn Polyakoff i William Tumas. "Synthetic pathways and processes in green chemistry. Introductory overview". Pure and Applied Chemistry 72, nr 7 (1.01.2000): 1207–28. http://dx.doi.org/10.1351/pac200072071207.
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ContentsGreen Chemistry in the International ContextThe Concept of green ChemistryDefinition of green chemistry | Green chemistry: Why now? | The historical context of green chemistry | The emergence of green chemistryThe Content of Green ChemistryAreas of green chemistry | Preliminary remarks | Alternative feedstocks | Benign reagents/synthetic pathways | Synthetic transformations | Solvents/reaction conditionsGreen Chemistry in the International ContextIt has come to be recognized in recent years, that the science of chemistry is central to addressing the problems facing the environment. Through the utilization of the various subdisciplines of chemistry and the molecular sciences, there is an increasing appreciation that the emerging area of green chemistry1is needed in the design and attainment of sustainable development. A central driving force in this increasing awareness is that green chemistry accomplishes both economic and environmental goals simultaneously through the use of sound, fundamental scientific principles. Recently, a basic strategy has been proposed for implementing the relationships between industry and academia, and hence, funding of the research that constitutes the engine of economic advancement; it is what many schools of economics call the "triple bottom line" philosophy, meaning that an enterprise will be economically sustainable if the objectives of environmental protection, societal benefit, and market advantage are all satisfied2. Triple bottom line is a strong idea for evaluating the success of environmental technologies. It is clear that the best environmentally friendly technology or discovery will not impact on the market if it is not economically advantageous; in the same way, the market that ignores environmental needs and human involvement will not prosper. This is the challenge for the future of the chemical industry, its development being strongly linked to the extent to which environmental and human needs can be reconciled with new ideas in fundamental research. On the other hand, it should be easy to foresee that the success of environmentally friendly reactions, products, and processes will improve competitiveness within the chemical industry. If companies are able to meet the needs of society, people will influence their own governments to foster those industries attempting such environmental initiatives. Of course, fundamental research will play a central role in achieving these worthy objectives. What we call green chemistry may in fact embody some of the most advanced perspectives and opportunities in chemical sciences.It is for these reasons that the International Union of Pure and Applied Chemistry (IUPAC) has a central role to play in advancing and promoting the continuing emergence and impact of green chemistry. When we think about how IUPAC furthers chemistry throughout the world, it is useful to refer to IUPAC's Strategic Plan. This plan demonstrates the direct relevance of the mission of IUPAC to green chemistry, and explains why there is growing enthusiasm for the pursuit of this new area as an appropriate activity of a scientific Union. The IUPAC Strategic Plan outlines among other goals:IUPAC will serve as a scientific, international, nongovernmental body in objectively addressing global issues involving the chemical sciences. Where appropriate, IUPAC will represent the interests of chemistry in governmental and nongovernmental forums.IUPAC will provide tools (e.g., standardized nomenclature and methods) and forums to help advance international research in the chemical sciences.IUPAC will assist chemistry-related industry in its contributions to sustainable development, wealth creation, and improvement in the quality of life.IUPAC will facilitate the development of effective channels of communication in the international chemistry community.IUPAC will promote the service of chemistry to society in both developed and developing countries.IUPAC will utilize its global perspective to contribute toward the enhancement of education in chemistry and to advance the public understanding of chemistry and the scientific method.IUPAC will make special efforts to encourage the career development of young chemists.IUPAC will broaden the geographical base of the Union and ensure that its human capital is drawn from all segments of the world chemistry community.IUPAC will encourage worldwide dissemination of information about the activities of the Union.IUPAC will assure sound management of its resources to provide maximum value for the funds invested in the Union.Through the vehicle of green chemistry, IUPAC can engage and is engaging the international community in issues of global importance to the environment and to industry, through education of young and established scientists, the provision of technical tools, governmental engagement, communication to the public and scientific communities, and the pursuit of sustainable development. By virtue of its status as a leading and internationally representative scientific body, IUPAC is able to collaborate closely in furthering individual national efforts as well as those of multinational entities.An important example of such collaboration in the area of green chemistry is that of IUPAC with the Organization for the Economical Cooperation and Development (OECD) in the project on "Sustainable Chemistry", aimed at promoting increased awareness of the subject in the member countries. During a meeting of the Environment Directorate (Paris, 6 June 1999), it was proposed that United States and Italy co-lead the activity, and that implementation of five recommendations to the member countries be accorded the highest priority, namely:research and developmentawards and recognition for work on sustainable chemistryexchange of technical information related to sustainable chemistryguidance on activities and tools to support sustainable chemistry programssustainable chemistry educationThese recommendations were perceived to have socio-economic implications for worldwide implementation of sustainable chemistry. How IUPAC and, in particular, its Divisions can contribute to this effort is under discussion. IUPAC is recognized for its ability to act as the scientific counterpart to OECD for all recommendations and activities. Although the initiatives being developed by the OECD are aimed primarily at determining the role that national institutions can play in facilitating the implementation and impact of green chemistry, it is recognized that each of these initiatives also has an important scientific component. Whether it is developing criteria or providing technical assessment for awards and recognition, identifying appropriate scientific areas for educational incorporation, or providing scientific insight into the areas of need for fundamental research and development, IUPAC can play and is beginning to play an important role as an international scientific authority on green chemistry.Other multinational organizations including, among others, the United Nations, the European Union, and the Asian Pacific Economic Community, are now beginning to assess the role that they can play in promoting the implementation of green chemistry to meet environmental and economic goals simultaneously. As an alternative to the traditional regulatory framework often implemented as a unilateral strategy, multinational governmental organizations are discovering that green chemistry as a nonregulatory, science-based approach, provides opportunities for innovation and economic development that are compatible with sustainable development. In addition, individual nations have been extremely active in green chemistry and provide plentiful examples of the successful utilization of green chemistry technologies. There are rapidly growing activities in government, industry, and academia in the United States, Italy, the United Kingdom, the Netherlands, Spain, Germany, Japan, China, and many other countries in Europe and Asia, that testify to the importance of green chemistry to the future of the central science of chemistry around the world.Organizations and Commissions currently involved in programs in green chemistry at the national or international level include, for example:U.S. Environmental Protection Agency (EPA), with the "Green Chemistry Program" which involves, among others, the National Science Foundation, the American Chemical Society, and the Green Chemistry Institute;European Directorate for R&D (DG Research), which included the goals of sustainable chemistry in the actions and research of the European Fifth Framework Programme;Interuniversity Consortium "Chemistry for the Environment", which groups about 30 Italian universities interested in environmentally benign chemistry and funds their research groups;UK Royal Society of Chemistry, which promotes the concept of green chemistry through a "UK Green Chemistry Network" and the scientific journal Green Chemistry;UNIDO-ICS (International Centre for Science and High Technology of the United Nations Industrial Development Organization) which is developing a global program on sustainable chemistry focusing on catalysis and cleaner technologies with particular attention to developing and emerging countries (the program is also connected with UNIDO network of centers for cleaner production); andMonash University, which is the first organization in Australia to undertake a green chemistry program.Footnotes:1. The terminology "green chemistry" or "sustainable chemistry" is the subject of debate. The expressions are intended to convey the same or very similar meanings, but each has its supporters and detractors, since "green" is vividly evocative but may assume an unintended political connotation, whereas "sustainable" can be paraphrased as "chemistry for a sustainable environment", and may be perceived as a less focused and less incisive description of the discipline. Other terms have been proposed, such as "chemistry for the environment" but this juxtaposition of keywords already embraces many diversified fields involving the environment, and does not capture the economic and social implications of sustainability. The Working Party decided to adopt the term green chemistry for the purpose of this overview. This decision does not imply official IUPAC endorsement for the choice. In fact, the IUPAC Committee on Chemistry and Industry (COCI) favors, and will continue to use sustainable chemistry to describe the discipline.2. J. Elkington, < http://www.sustainability.co.uk/sustainability.htm
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Tan, Lan, i Abdul Rahman. "An Economical, Sustainable Pathway to Indole-Containing Oxindoles: Iron-Catalyzed 1,6-Conjugate Addition in Glycerol". Sustainability 10, nr 8 (17.08.2018): 2922. http://dx.doi.org/10.3390/su10082922.
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The search for economical, sustainable and practical pathways in synthetic science would contribute to improving resource efficiency, developing a recycling economy and driving new-type urbanization. Green synthesis has established firm ground providing the right green yardstick for development of a sustainable approach to bioactive high-added value molecules and drug discovery, and further development of sustainable manufacturing processes in the pharmaceutical industry toward a green resource efficient economy. In this study, the combination of FeCl3 and glycerol exhibits a versatile and high catalytic activity in the atom economical 1,6-conjugated addition of para-quinone methides derived from isatins with indoles using the right green yardstick. The sustainable pathway provides the preparation of bioactive indole-containing oxindoles in excellent yields with superior advantages, such as the ready availability, low price and environmentally benign character of iron catalysis, easy product separation, cheap and safe bio-renewable glycerol as a green solvent, and catalytic system recycling under mild conditions.
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Kumar, Suresh, Bhavna Saroha, Gourav Kumar, Ekta Lathwal, Sanjeev Kumar, Badri Parshad, Meena Kumari, Naveen Kumar, Mabel M. Mphahlele-Makgwane i Peter R. Makgwane. "Recent Developments in Nanocatalyzed Green Synthetic Protocols of Biologically Potent Diverse O-Heterocycles—A Review". Catalysts 12, nr 6 (15.06.2022): 657. http://dx.doi.org/10.3390/catal12060657.
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The dynamic growth in green organic synthetic methodologies for diverse heterocyclic scaffolds has substantially contributed to the field of medicinal chemistry over the last few decades. The use of hybrid metal nanocatalysts (NCs) is one such benign strategy for ensuring the advancement of modern synthetic chemistry by adhering to the principles of green chemistry, which call for a sustainable catalytic system that converts reacting species into profitable chemicals at a faster rate and tends to reduce waste generation. The metal nanoparticles (NPs) enhance the exposed surface area of the catalytic active sites, thereby making it easier for reactants and metal NCs to have an effective interaction. Several review articles have been published on the preparation of metal NCs and their uses for various catalytic heterocyclic transformations. This review will summarize different metal NCs for the efficient green synthesis of various O-heterocycles. Furthermore, the review will provide a concise overview of the role of metal NCs in the synthesis of O-heterocycles and will be extremely useful to researchers working on developing novel green and simple synthetic pathways to various O-heterocyclic-derived molecules.
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Appy, Lucie, Crystalle Chardet, Suzanne Peyrottes i Béatrice Roy. "Synthetic Strategies for Dinucleotides Synthesis". Molecules 24, nr 23 (27.11.2019): 4334. http://dx.doi.org/10.3390/molecules24234334.
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Dinucleoside 5′,5′-polyphosphates (DNPs) are endogenous substances that play important intra- and extracellular roles in various biological processes, such as cell proliferation, regulation of enzymes, neurotransmission, platelet disaggregation and modulation of vascular tone. Various methodologies have been developed over the past fifty years to access these compounds, involving enzymatic processes or chemical procedures based either on P(III) or P(V) chemistry. Both solution-phase and solid-support strategies have been developed and are reported here. Recently, green chemistry approaches have emerged, offering attracting alternatives. This review outlines the main synthetic pathways for the preparation of dinucleoside 5′,5′-polyphosphates, focusing on pharmacologically relevant compounds, and highlighting recent advances.
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Yelmame, Ganesh B., i SHRIKANT B. JAGTAP. "Review on Perimidines: A synthetic Pathways Approach". Material Science Research India 18, nr 1 (30.04.2021): 14–26. http://dx.doi.org/10.13005/msri/180103.
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Perimidines are available in an assortment of drugs and general use industrial structures and perimidines are also significant primary theme because of their extraordinary method of physiological activity. Thus the underlying significance of perimidine moiety has evoked a lot of interest in the field of natural blend and compound science to build up some better than ever amalgamation of this atomic skeleton. In this review, we have depicted a modern outline on the new advances in the different manufactured approaches of perimidine. The review covers the essential applied and down to earth synergist blend like, green methodologies, metal catalysed responses, microwave illumination, grinding and so forth which are critical for developing perimidine skeleton. This review will fulfill the assumptions for peruses who are keen on the advancement of the field and searching for an update. It will animate analysts to grow new and innovative manufactured admittance to this heterocyclic framework, which will be instrumental in the headway of perimidine science. This review provides an overview of various synthetic methodologies for the synthesis of a wide range of perimidine derivatives with applications in material chemistry, drug discovery, polymer chemistry, photo sensors, dye chemistry, and other fields.
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Aghahosseini, Hamideh, Ali Ramazani, Farideh Gouranlou i Sang Woo Joo. "Nanoreactors Technology in Green Organic Synthesis". Current Organic Synthesis 14, nr 6 (28.09.2017): 810–64. http://dx.doi.org/10.2174/1570179413666161008200641.
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Background: Nanoreactors technology represents a promising tool for efficient and selective organic synthesis typically under “green” and sustainable reaction conditions. These structures with generating a confined reaction environment to accommodate that both reactants and catalysts can change the reaction pathways and induce new activities and selectivities. Objective: The paper reviews literature examples in which nanoreactors were employed in various types of organic and metal catalyzed reactions including multicomponent reactions, palladium-catalyzed coupling reactions, olefin metathesis, aza-Cope rearrangement, allylic alcohol isomerization, cyclization reactions, ring opening reactions, halogenation reactions, hydrolysis reactions, hydroformylation reactions, cascade reactions, addition reactions, oxidation reactions and reduction reactions. The reactions' survey is accompanied with the explanation of structure and performance of nanoreactors that are applied there. Conclusion: The availability of comprehensive information about the role of nanoreactors technology in green organic synthesis and investigation of different aspects of them such as their structures, mechanisms and synthetic utility can assist researchers in designing the greener approaches in organic synthesis.
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Quivelli, Andrea Francesca, Federico Vittorio Rossi, Chiara Alario, Francesco Sannicolò, Paola Vitale, Joaquín García-Álvarez, Filippo Maria Perna i Vito Capriati. "Green Solvents for Eco-Friendly Synthesis of Dimethindene: A Forward-Looking Approach". Molecules 27, nr 21 (5.11.2022): 7594. http://dx.doi.org/10.3390/molecules27217594.
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Dimethindene is a selective histamine H1 antagonist and is commercially available as a racemate. Upon analyzing the synthetic pathways currently available for the industrial preparation of dimethindene, we set up a sustainable approach for the synthesis of this drug, switching from petroleum-based volatile organic compounds (VOCs) to eco-friendly solvents, such as 2-methyltetrahydrofuran (2-MeTHF) and cyclopentyl methyl ether (CPME) belonging to classes 3 and 2, respectively. Beyond decreasing the environmental impact of the synthesis (E-factor: 24.1–54.9 with VOCs; 12.2–22.1 with 2-MeTHF or CPME), this switch also improved the overall yield of the process (from 10% with VOCs to 21–22% with 2-MeTHF or CPME) and remarkably simplified the manual operations, working under milder conditions. Typical metrics applied at the first and second pass, according to the CHEM21 metrics toolkit, were also calculated for the whole synthetic procedure of dimethindene, and the results were compared with those of the classical procedure.
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Jicsinszky, László, Federica Rossi, Roberto Solarino i Giancarlo Cravotto. "Comparison of the Conventional and Mechanochemical Syntheses of Cyclodextrin Derivatives". Molecules 28, nr 2 (4.01.2023): 467. http://dx.doi.org/10.3390/molecules28020467.
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Many scientists are working hard to find green alternatives to classical synthetic methods. Today, state-of-the-art ultrasonic and grinding techniques already drive the production of organic compounds on an industrial scale. The physicochemical and chemical behavior of cyclodextrins often differs from the typical properties of classic organic compounds and carbohydrates. The usually poor solubility and complexing properties of cyclodextrins can require special techniques. By eliminating or reducing the amount of solvent needed, green alternatives can reform classical synthetic methods, making them attractive for environmentally friendly production and the circular economy. The lack of energy-intensive synthetic and purification steps could transform currently inefficient processes into feasible methods. Mechanochemical reaction mechanisms are generally different from normal solution-chemistry mechanisms. The absence of a solvent and the presence of very high local temperatures for microseconds facilitate the synthesis of cyclodextrin derivatives that are impossible or difficult to produce under classical solution-chemistry conditions. Although mechanochemistry does not provide a general solution to all problems, several good examples show that this new technology can open up efficient synthetic pathways.
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Rusling, James F. "Green synthesis via electrolysis in microemulsions". Pure and Applied Chemistry 73, nr 12 (1.01.2001): 1895–905. http://dx.doi.org/10.1351/pac200173121895.
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Electrolysis in microemulsions is a promising approach for environmentally friendly chemical synthetic methods of the future. Employing microemulsions instead of organic solvents for electrosynthesis has the advantages of lower toxicity and cost, high dissolving power for reactants and mediators of unlike solubility, enhancement of reaction rates by controlling the reduction potentials of mediators, possible reaction pathway control, and recycling of microemulsion components. This paper reviews recent progress in using microemulsions for direct and mediated electrosynthesis, including formation of carboncarbon bonds. Rates of mediated reactions can be controlled by manipulating microemulsion composition. Examples are presented, in which reaction pathways of direct and mediated electrolyses can be controlled with microemulsions to give desired products in high yields. Such control has been demonstrated with dissolved and surface-bound mediators. For a covalently linked scaffold of poly(l-lysine) and cobalt corrin vitamin B12 hexacarboxylate attached to graphite, catalytic turnover rate for reduction of 1,2-dibromocylcohexane was optimized by optimizing microemulsion composition.
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Khajuria, Ajay, Shubam Sudan i Mohit Kapoor. "Brief Overview on Synthesis and Application of Ni–Doped Carbon Dots". ECS Transactions 107, nr 1 (24.04.2022): 6129–36. http://dx.doi.org/10.1149/10701.6129ecst.
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Carbon dots (CDs) are semiconductor materials with sizes ranging from 2 to 10 nm. Among these CDs, nickel CDs (Ni@CDs) materials have piqued researchers' curiosity in the past years due to their specific properties, such as strong catalytic activity, good stability, great hydrophilicity, and high oxidation states. Several synthetic pathways exist for the synthesis of Ni@CDs, such as hydrothermal method, microwave irradiation, green synthesis, pyrolytic decomposition, precipitation method, and electrochemical route. These Ni@CDs have shown application in charge transfer, excellent thermodynamic stability, luminescent properties, high chemical and photo-stability, opto-electronic devices, catalysis, sensing, and drug delivery. In this review, various synthetic methods had been explored extensively along with their numerous applications.
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Gafurov, Zufar N., Alexey A. Kagilev, Artyom O. Kantyukov, Oleg G. Sinyashin i Dmitry G. Yakhvarov. "Hydrogenation reaction pathways in chemistry of white phosphorus". Pure and Applied Chemistry 91, nr 5 (27.05.2019): 797–810. http://dx.doi.org/10.1515/pac-2018-1007.
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Abstract Approaches for preparation of P–H bond containing derivatives directly from white phosphorus are summarized in this microreview. Transfer hydrogenation of P4 involving the activation and reaction of white phosphorus in the coordination sphere of transition metal complexes is a convenient and powerful route to the hydrogenated compounds. Electrochemical methods have also become popular in modern synthetic chemistry; these provide easy access to highly reactive intermediates, which can be selectively generated in situ and used for subsequent synthetic processes. These electrochemical routes provide efficient and environmentally safe methods for preparation of phosphorus derivatives bearing P–H bond. The mechanisms of the proposed processes and the nature of the intermediates formed in the overall electrochemical process are disclosed. The methods elaborated operate under the principals of “green chemistry” and can be considered as efficient alternatives to some classical pathways.
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Singh, KalpanaVirendra. "MICROWAVE ASSISTED SYNTHESIS, A GREEN PROTOCOL FOR DEVELOPMENT OF NEW AND ADVANCED DRUG DELIVERY SYSTEMS, A REVIEW". International Journal of Research -GRANTHAALAYAH 3, nr 9SE (30.09.2015): 1–4. http://dx.doi.org/10.29121/granthaalayah.v3.i9se.2015.3126.
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Medicinal Chemistry community is considering new chemical processes, which are environmentally benign. Environmentally benign synthetic protocols have become the primary concern during complex drug discovery processes. Green chemistry is providing algorithms for protecting the environment, not by cleaning it, but by inventing new chemical processes that fuel the Economy and lifestyles, without causing any damage to the environment. Microwave assisted techniques has opened up new opportunities to the synthetic chemists in the form of new improved reaction pathways, that are not otherwise feasible. MAOS has reduced the reaction times from hours or days to minutes leading to efficient economic way for synthesis of large number of molecules. Present Review article attempts to focus on what is MAOS, how it is generated and works going on in this area.
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De Martino, M. Teresa, Loai K. E. A. Abdelmohsen, Floris P. J. T. Rutjes i Jan C. M. van Hest. "Nanoreactors for green catalysis". Beilstein Journal of Organic Chemistry 14 (29.03.2018): 716–33. http://dx.doi.org/10.3762/bjoc.14.61.
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Sustainable and environmentally benign production are key drivers for developments in the chemical industrial sector, as protecting our planet has become a significant element that should be considered for every industrial breakthrough or technological advancement. As a result, the concept of green chemistry has been recently defined to guide chemists towards minimizing any harmful outcome of chemical processes in either industry or research. Towards greener reactions, scientists have developed various approaches in order to decrease environmental risks while attaining chemical sustainability and elegancy. Utilizing catalytic nanoreactors for greener reactions, for facilitating multistep synthetic pathways in one-pot procedures, is imperative with far-reaching implications in the field. This review is focused on the applications of some of the most used nanoreactors in catalysis, namely: (polymer) vesicles, micelles, dendrimers and nanogels. The ability and efficiency of catalytic nanoreactors to carry out organic reactions in water, to perform cascade reaction and their ability to be recycled will be discussed.
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Irwansyah, Ferli Septi, Atiek Rostika Noviyanti, Diana Rakhmawaty Eddy i Risdiana Risdiana. "Green Template-Mediated Synthesis of Biowaste Nano-Hydroxyapatite: A Systematic Literature Review". Molecules 27, nr 17 (30.08.2022): 5586. http://dx.doi.org/10.3390/molecules27175586.
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Hydroxyapatite (HA) is a well-known calcium phosphate ingredient comparable to human bone tissue. HA has exciting applications in many fields, especially biomedical applications, such as drug delivery, osteogenesis, and dental implants. Unfortunately, hydroxyapatite-based nanomaterials are synthesized by conventional methods using reagents that are not environmentally friendly and are expensive. Therefore, extensive efforts have been made to establish a simple, efficient, and green method to form nano-hydroxyapatite (NHA) biofunctional materials with significant biocompatibility, bioactivity, and mechanical strength. Several types of biowaste have proven to be a source of calcium in forming HA, including using chicken eggshells, fish bones, and beef bones. This systematic literature review discusses the possibility of replacing synthetic chemical reagents, synthetic pathways, and toxic capping agents with a green template to synthesize NHA. This review also shed insight on the simple green manufacture of NHA with controlled shape and size.
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Jaffri, Shaan Bibi, i Khuram Shahzad Ahmad. "Phytofunctionalized silver nanoparticles: green biomaterial for biomedical and environmental applications". Reviews in Inorganic Chemistry 38, nr 3 (28.08.2018): 127–49. http://dx.doi.org/10.1515/revic-2018-0004.
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AbstractVariegated physicochemical routes with emerging modifications have been adopted and reported for silver nanoparticle synthesis for centuries. Nano-biotechnology aimed at the synthesis of nanomaterials, including silver nanoparticles, through utilization of biological media has acquired an auspicious role in science for human welfare. Despite recurrent nanoscale researches on physicochemical routes, coeval stages are predominated by greener methods in silver nanoparticle synthesis for the utilization of its inherent toxicity and exceedingly smaller sizes for biological and environmental applications. One of the principles of green routes for silver nanoparticle synthesis is reduction and stabilization via phytochemicals extracted from plants in a one-pot protocol of phytofunctionalization. Plants are preferred for their abundant availability, environmental non-toxicity and economical favorability and chiefly for the ease of aptness, unlike microbial pathways having tedious requirements of cellular culture maintenance conditions. The present work reviewed the most recent milestones set in the selection of types and parts of plants and optimized synthetic conditions employed in the fabrication of silver nanoparticles, in addition to quantitative and qualitative characterization. Furthermore, the use of phytofunctionalized silver nanoparticles for microbial growth inhibition and environmental remediation was also studied. Through the meticulous review of literature, potential applications were highlighted, which can provide researchers with a plethora of avenues for future investigations for remediation of the environment, in terms of both combating pathogenic microbes and environmental detoxification.
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Wang, Xiaoxue, Yujie Qian, Hanyu Gao, Connor W. Coley, Yiming Mo, Regina Barzilay i Klavs F. Jensen. "Towards efficient discovery of green synthetic pathways with Monte Carlo tree search and reinforcement learning". Chemical Science 11, nr 40 (2020): 10959–72. http://dx.doi.org/10.1039/d0sc04184j.
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Bull, James R. "Preface". Pure and Applied Chemistry 72, nr 7 (1.01.2000): v. http://dx.doi.org/10.1351/pac20007207ii.
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The evolving face of contemporary chemistry is characterized by unprecedented societal demand for the goods and services of the chemical industry, tempered by growing awareness that finite resources must be conserved and their exploitation optimized. At the same time, environmental protection has become a global concern, and the chemical industry is increasingly obliged to reexamine conventional methodologies, and to seek ways of developing and applying more efficient and environmentally benign strategies for future sustainable growth. The tandem concepts of discovery and exploitation are obviously as old as the industry itself, but there is new urgency in the quest for solutions that will halt and reverse some of the negative effects of historical development and, at the same time, seize the opportunities offered by the extraordinary advances in chemical sciences during recent years.The twin challenges of increasing synthetic efficiency in chemical transformations, and minimizing environmentally hostile waste offer irresistible opportunities for new-age ingenuity. It is in this climate that new approaches to these problems have coalesced into a distinctive discipline, which has been variously described and named but has, as its central thrust, the strategic objectives of increased efficiency, sustainability, and, ultimately, societal benefit. These objectives identify closely with the vision of IUPAC, which is eloquently expressed in two of the goals defined in the current strategic plan, namely to contribute to the advancement of research in the chemical sciences throughout the world and to assist chemistry-related industry in its contributions to sustainable development, wealth creation, and the improvement of the quality of life.A Working Party on Synthetic Pathways and Processes in Green Chemistry was established in 1996, under the auspices of the Commission on Physical Organic Chemistry (Commission III.2) of the IUPAC Organic and Biomolecular Division, with a mandate to promote and disseminate awareness of environmentally compatible synthetic pathways (green chemistry), throughout the academic and industrial scientific research community. In 1999 this group, in close collaboration with the IUPAC Subcommittee on Organic Synthesis, initiated a project to publish a Symposium-in-Print on Green Chemistry, and undertook to compile a collection of expert reviews on aspects of the topic, underpinned by an introductory account of the evolution of the project, its rationale, and its interfaces with complementary initiatives and organisations.This volume represents the culmination of that undertaking, and the introductory overview, comprising contributions by members of the Working Party, gives a detailed account of the role and interest of IUPAC in promoting this initiative, and sets the scene for the ensuing Symposium-in-Print, with an interpretation of the meaning of the term "green chemistry" and an account of the historical emergence of the concept. This is followed by a synoptic preamble, in which the content and purpose of individual reviews in the Symposium-in-Print are summarized. Although the preamble adopts a sequence of presentation based upon the logic imposed by the title theme of synthetic pathways and processes, the influential role of the Organization for Economic Cooperation and Development (OECD) is recognized by adoption of their recommended delineation of topics for grouping the ensuing reviews. The Symposium-in-Print sets out to capture the current status of the discipline and to project the boundless opportunities and challenges confronting contemporary organic synthesis and its practice in a changing world, increasingly sensitized to the finite bounds of natural resources and the vulnerability of the biosphere. It offers evidence that current problems are being addressed and can be solved, and engenders expectations that future problems can be anticipated and prevented. Most importantly, the collective expertise and commitment of the contributors is expected to furnish inspirational guidance to practicing scientists and students of chemistry, to participate in shaping a more environmentally benign future, in which the synthetic pathways and processes in chemistry are fully reconciled with societal expectations for ever-improving quality of life.J. R. BullIUPAC Special Topics Editor
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Ajani, Olayinka Oyewale, i King T. Iyaye. "Recent advances on oxadiazole motifs: Synthesis, reactions and biological activities". Mediterranean Journal of Chemistry 10, nr 5 (12.05.2020): 418. http://dx.doi.org/10.13171/mjc10502005121200ooa.
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<p>1,3,4-oxadiazole derivatives have shown to have diverse and vast applications, from medicinal chemistry for the treatment and possible treatment of various ailments to its application in the industrial development when used as corrosion inhibitions and light emitting diodes. These diverse applications can be as a result of the numerous viable synthetic pathways illustrated in this review. 1,3,4-oxadiazoles can be synthesized in very high yields, using green approaches and having various life-changing applications. This review explores the various recent synthetic routes available for the development of 1,3,4-oxadiazoles and their biological activities.</p>
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Santi, Micol, Luca Sancineto, Vanessa Nascimento, Juliano Braun Azeredo, Erika V. M. Orozco, Leandro H. Andrade, Harald Gröger i Claudio Santi. "Flow Biocatalysis: A Challenging Alternative for the Synthesis of APIs and Natural Compounds". International Journal of Molecular Sciences 22, nr 3 (20.01.2021): 990. http://dx.doi.org/10.3390/ijms22030990.
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Biocatalysts represent an efficient, highly selective and greener alternative to metal catalysts in both industry and academia. In the last two decades, the interest in biocatalytic transformations has increased due to an urgent need for more sustainable industrial processes that comply with the principles of green chemistry. Thanks to the recent advances in biotechnologies, protein engineering and the Nobel prize awarded concept of direct enzymatic evolution, the synthetic enzymatic toolbox has expanded significantly. In particular, the implementation of biocatalysts in continuous flow systems has attracted much attention, especially from industry. The advantages of flow chemistry enable biosynthesis to overcome well-known limitations of “classic” enzymatic catalysis, such as time-consuming work-ups and enzyme inhibition, as well as difficult scale-up and process intensifications. Moreover, continuous flow biocatalysis provides access to practical, economical and more sustainable synthetic pathways, an important aspect for the future of pharmaceutical companies if they want to compete in the market while complying with European Medicines Agency (EMA), Food and Drug Administration (FDA) and green chemistry requirements. This review focuses on the most recent advances in the use of flow biocatalysis for the synthesis of active pharmaceutical ingredients (APIs), pharmaceuticals and natural products, and the advantages and limitations are discussed.
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Wahab, Maryam, i Srinivas Janaswamy. "A review on biogenic silver nanoparticles as efficient and effective antidiabetic agents". Functional Food Science 3, nr 7 (14.07.2023): 93. http://dx.doi.org/10.31989/ffs.v3i7.1119.
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The frontiers of nanomedicine are consistently being challenged by the gradually expanding knowledge of the properties of nanoparticles. Toward this end, biogenic synthesis of silver nanoparticles utilizing natural compounds in plants as reducing and capping agents grabbed considerable attention, in lieu of synthetic hazardous physical and chemical techniques. Green synthesis of silver nanoparticles (AgNPs) has proven safe and effective in treating type 2 diabetes mellitus. Currently, biogenic silver nanoparticles have gained importance as safe and efficient antiglycation agents. Therapeutic strategies by employing nanomedicines from natural sources have been initiated to end the limitations of currently available medications for the treatment of various disorders, including diabetes, Alzheimer’s, cancer, and hepatitis. This article highlights the medicinal efficacy of silver nanoparticles synthesized from different plant extracts for their antidiabetic potential characterized through various in vivo and in vitro assays and unravels their unique properties. This article also focuses on the signaling pathways linked to type II diabetes and the demand for nanomedicine and greener pathways for future pharmacological industries.Keywords: Biogenic silver nanoparticles, antioxidant, Type 2 Diabetes Mellitus (T2DM), α-glucosidase assay, α-amylase assay
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Aliyu, M., Z. M. Bonomi i A. S. Idoko. "Dietary phytochemicals targeting Nf-<i>K</i>B signalling pathways: Potential cancer chemoprevention strategy". Dutse Journal of Pure and Applied Sciences 9, nr 2a (14.07.2023): 179–90. http://dx.doi.org/10.4314/dujopas.v9i2a.18.
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Chemoprevention is an approach involving the use of natural or synthetic substances to prevent the risk of development many diseases including cancer. Nuclear factor–kappa B (NF-kB) signaling pathways is crucial in either inducing processes of inflammation and apoptosis. As a result, it is implicated in numerous stages of carcinogenesis through collaboration with several signaling pathways and molecules. This transcription factor may be regarded as key target for cancer chemoprevention. Phytochemicals available in food as well as green plants have been demonstrated to have cancer protection activities by modulating important cellular signaling pathways including NF-kB pathway. Numerous phytochemicals, primarily components of edible vegetables and plants, have been reported in the literature to modulate NF-kB. Suppressing NF-kB may provide protection to the normal cells against development and spread of cancer. Majority of phytochemicals use various mechanisms to inhibit NF-kB. Different phytochemicals combinations present in a natural food may enhance their modulating potential on NF-kB and consequently elicit cancer prevention. This article reviews the current understanding of the potential effect of some phytochemicals and their combinations on NF-kB activities.
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Ousji, Ons, i Lekha Sleno. "Structural Elucidation of Novel Stable and Reactive Metabolites of Green Tea Catechins and Alkyl Gallates by LC-MS/MS". Antioxidants 11, nr 9 (23.08.2022): 1635. http://dx.doi.org/10.3390/antiox11091635.
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Synthetic gallic acid derivatives are employed as additives in food, personal care products, and pharmaceutical formulations. Despite their widespread use, little is known about their human exposure, health effects, and metabolism. Green tea catechins are natural antioxidants, known for their health-promoting properties, and are also employed as food additives or in personal care products. The objective of this study was to establish metabolic pathways involved in the biotransformation of green tea catechins and synthetic gallate esters. Liquid chromatography coupled with high-resolution tandem mass spectrometry (LC-HRMS/MS) was used to elucidate oxidative and methylated metabolites, in addition to glutathione conjugates, formed in vitro using human liver microsomal incubations. The developed method was applied to 14 different parent compounds with a wide range of polarities, for the structural elucidation of many known and novel metabolites. These results serve to inform about the wide variety of possible metabolites formed upon exposure to these compounds.
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Jeon, Jong-Rok, Petr Baldrian, Kumarasamy Murugesan i Yoon-Seok Chang. "Laccase-catalysed oxidations of naturally occurring phenols: from in vivo biosynthetic pathways to green synthetic applications". Microbial Biotechnology 5, nr 3 (26.07.2011): 318–32. http://dx.doi.org/10.1111/j.1751-7915.2011.00273.x.
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Arcadi, Antonio, Valerio Morlacci i Laura Palombi. "Synthesis of Nitrogen-Containing Heterocyclic Scaffolds through Sequential Reactions of Aminoalkynes with Carbonyls". Molecules 28, nr 12 (12.06.2023): 4725. http://dx.doi.org/10.3390/molecules28124725.
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Sequential reactions of aminoalkynes represent a powerful tool to easily assembly biologically important polyfunctionalized nitrogen heterocyclic scaffolds. Metal catalysis often plays a key role in terms of selectivity, efficiency, atom economy, and green chemistry of these sequential approaches. This review examines the existing literature on the applications of reactions of aminoalkynes with carbonyls, which are emerging for their synthetic potential. Aspects concerning the features of the starting reagents, the catalytic systems, alternative reaction conditions, pathways and possible intermediates are provided.
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Reis, Ana Rita, Nuno Viduedo, Daniel Raydan i Maria Manuel B. Marques. "Bimetallic (or Multimetallic) Synthesis of N-Heterocycles". Catalysts 13, nr 9 (2.09.2023): 1268. http://dx.doi.org/10.3390/catal13091268.
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Bimetallic (or multimetallic) catalysis has emerged as a powerful tool in modern chemical synthesis, offering improved reaction control and versatility. This review focuses on the recent developments in bimetallic sequential catalysis for the synthesis of nitrogen heterocycles, which are essential building blocks in pharmaceuticals and fine chemicals. The cooperative action of two (sometimes more) different metal catalysts enables intricate control over reaction pathways, enhancing the selectivity and efficiency of the synthesis of N-heterocyclic compounds. By activating less reactive substrates, this multimetal catalytic strategy opens new synthetic possibilities for challenging compounds. The use of catalytic materials in bimetallic systems reduces waste and improves atom efficiency, aligning with green chemistry principles. With a diverse range of metal combinations and reaction conditions, bimetallic catalysis provides access to a broad array of N-heterocyclic compounds with various functionalities. This paper highlights the significant progress made in the past decade in this topic, emphasizing the promising potential of bimetallic catalysis in drug discovery and the fine chemical industries.
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Sharma, Sachin, Gaurav Joshi, Sourav Kalra, Sandeep Singh i Raj Kumar. "Synthetic Versus Enzymatic Pictet-Spengler Reaction: An Overview". Current Organic Synthesis 15, nr 7 (16.10.2018): 924–39. http://dx.doi.org/10.2174/1570179415666180613084014.
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Background: Pictet-Spengler reactions is an irreplaceable part of cyclization reaction leading to the formation of indispensable heterocyclic moieties including imidazole, benzoxazole, pyrrole, indole and others having immense biological and chemical significance. Researchers have explored this reaction using different types of catalysts and reactions conditions (including solvents, acids, etc.) to ensure the better selectivity, less reaction time and high product yields. A total of five Pictet-Spenglerases have been discovered from various sources including plants, animals, fungi, and microbes, and are responsible for the synthesis of various important alkaloids of biological medicinal importance. Objective: The present review is a strenuous effort to assemble information mainly focusing on synthetic as well as biological Pictet-Spengler reactions catalysed by enzymes called Pictet-Spenglerase. Conclusion: In the present review, the recent advances in the PS-mediated synthesis of diverse heterocycles such as tetrahydroisoquinoline, tetrahydro-β-carbolines, tetrahydroimidazopyridines and other fused heterocycles via chemical as well as enzymatic pathways have been covered. The compounds find their scope as medicinal agents for the treatment of cancer, tuberculosis, bacterial infection, leishmanial, etc. The compilation is expected to provide a mechanistic insight to chemists to enhance the reaction condition, yields and another parameter to ensure the safe and inexpensive reaction conditions considering the “Green-Concept” of chemistry.
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Bociort, Flavia, Adelina Cheveresan, Razvan Dragoi, Alina Heghes, Camelia Szuhanek, Matilda Radulescu, Delia Berceanu-Vaduva, Alina Tischer i Andrei Motoc. "Green and Synthetic Metallic Nanoparticles - Obtaining, Characterization and Biological Evaluation in Association with Lupeol". Revista de Chimie 71, nr 5 (29.05.2020): 299–304. http://dx.doi.org/10.37358/rc.20.5.8137.
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The field of metal nanotechnology continues to draw the attention of researchers from different areas due to the outstanding properties of nanoparticles. The main aims of this research were to obtain and to study two types of gold nanoparticles; different obtaining pathways (the chemical synthesis and the biosynthesis based on an aqueous extract of lemon balm) were involved in this research. The chemically synthesized nanoparticles were loaded with lupeol. After a preliminary physico-chemical characterization, the compounds obtained were tested in order to evaluate the effects on the viability of colon cancer cells. The formulation of these new gold nanoparticles with average size between 38 and 82 nm, with a good stability against the tendency to form agglomerations according to the Zeta potential values, was confirmed by UV-Vis spectra; the particles containing lupeol have show the best activity against the colon cancer cells.
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Tundo, Pietro. "Preface". Pure and Applied Chemistry 84, nr 3 (1.01.2012): vi. http://dx.doi.org/10.1351/pac20128403vi.
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The first Special Topic issue devoted to green chemistry was published in Pure and Applied Chemistry in July 2000 [Pure Appl. Chem.72, 1207-1403 (2000)]. Since then, three collections of works have been published, arising from the recently launched IUPAC series of International Conferences on Green Chemistry:- 1st International Conference on Green Chemistry (ICGC-1), Dresden, Germany, 10-15 September 2006: Pure Appl. Chem.79, 1833-2100 (2007)- 2nd International Conference on Green Chemistry (ICGC-2), Moscow, Russia, 14-20 September 2008: Pure Appl. Chem.81, 1961-2129 (2009)- 3rd International Conference on Green Chemistry (ICGC-3), Ottawa, Canada, 15-18 August 2010: Pure Appl. Chem.83, 1343-1406 (2011)This Special Topic issue forms part of the series on green chemistry, and is an outcome of IUPAC Project No. 2008-016-1-300: “Chlorine-free Synthesis for Green Chemistry” previously announced in Chemistry International, May-June, p. 22 (2011).The IUPAC Subcommittee on Green Chemistry was founded in July 2001 and has selected the following definition for green chemistry [1]: “The invention, design and application of chemical products and processes to reduce or to eliminate the use and generation of hazardous substances” [2].Much controversy persists about the appropriate terminology to describe this new field of research. Which term should be selected, “green chemistry” or “sustainable chemistry”? Perhaps consensus can be achieved if different purposes and interests of chemists are reconciled. If we are involved in fundamental research devoted to the discovery of new reaction pathways and reagents, “green” is the best word because it defines these intents, thus the term “green chemistry” would be the best name for this field of research. If we are interested in exploitation of a process or a product that must be profitable, then such chemical manufacture must be sustainable by many criteria (price, competition, profit, environment, etc.), and, accordingly, “sustainable chemistry” is the term that best defines this objective.This Special Topic issue has been designed with the intent to explore the restriction, or preferably prevention, of the use of halogenated compounds, whenever feasible, through the assembly and reporting of already identified information. This intent has been pursued through innovative synthetic pathways using clearly identified production drivers (e.g., energy consumption, environmental impact, economical feasibility, etc.). In past decades, scientific knowledge and feasible technologies were unavailable, but we now have enough expertise to pursue discontinuation of hazardous and toxic reagents. In fact, the replacement of reagents that are toxic, dangerous, and produced by eco-unfriendly processes is still an underdeveloped area of chemistry today.Pietro TundoProject Co-chair1. For a short history of green chemistry, see: P. Tundo, F. Aricò. Chem. Int.29(5), (2007).2. P. Anastas, D. Black, J. Breen, T. Collins, S. Memoli, J. Miyamoto, M. Polyakoff, W. Tumas, P. Tundo. Pure Appl. Chem.72, 1207 (2000).
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Tarnowicz-Ligus, Stanisława, i Anna Trzeciak. "Heck Transformations of Biological Compounds Catalyzed by Phosphine-Free Palladium". Molecules 23, nr 9 (1.09.2018): 2227. http://dx.doi.org/10.3390/molecules23092227.
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The development and optimization of synthetic methods leading to functionalized biologically active compounds is described. Two alternative pathways based on Heck-type reactions, employing iodobenzene or phenylboronic acid, were elaborated for the arylation of eugenol and estragole. Cinnamyl alcohol was efficiently transformed to saturated arylated aldehydes in reaction with iodobenzene using the tandem arylation/isomerization sequential process. The arylation of cinnamyl alcohol with phenylboronic acid mainly gave unsaturated alcohol, while the yield of saturated aldehyde was much lower. Catalytic reactions were carried out using simple, phosphine-free palladium precursors and water as a cosolvent, following green chemistry rules as much as possible.
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Rozzi, Elena, Francesco Demetrio Minuto, Andrea Lanzini i Pierluigi Leone. "Green Synthetic Fuels: Renewable Routes for the Conversion of Non-Fossil Feedstocks into Gaseous Fuels and Their End Uses". Energies 13, nr 2 (15.01.2020): 420. http://dx.doi.org/10.3390/en13020420.
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Innovative renewable routes are potentially able to sustain the transition to a decarbonized energy economy. Green synthetic fuels, including hydrogen and natural gas, are considered viable alternatives to fossil fuels. Indeed, they play a fundamental role in those sectors that are difficult to electrify (e.g., road mobility or high-heat industrial processes), are capable of mitigating problems related to flexibility and instantaneous balance of the electric grid, are suitable for large-size and long-term storage and can be transported through the gas network. This article is an overview of the overall supply chain, including production, transport, storage and end uses. Available fuel conversion technologies use renewable energy for the catalytic conversion of non-fossil feedstocks into hydrogen and syngas. We will show how relevant technologies involve thermochemical, electrochemical and photochemical processes. The syngas quality can be improved by catalytic CO and CO2 methanation reactions for the generation of synthetic natural gas. Finally, the produced gaseous fuels could follow several pathways for transport and lead to different final uses. Therefore, storage alternatives and gas interchangeability requirements for the safe injection of green fuels in the natural gas network and fuel cells are outlined. Nevertheless, the effects of gas quality on combustion emissions and safety are considered.
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Cascione, Mariafrancesca, Loris Rizzello, Daniela Manno, Antonio Serra i Valeria De Matteis. "Green Silver Nanoparticles Promote Inflammation Shutdown in Human Leukemic Monocytes". Materials 15, nr 3 (20.01.2022): 775. http://dx.doi.org/10.3390/ma15030775.
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The use of silver nanoparticles (Ag NPs) in the biomedical field deserves a mindful analysis of the possible inflammatory response which could limit their use in the clinic. Despite the anti-cancer properties of Ag NPs having been widely demonstrated, there are still few studies concerning their involvement in the activation of specific inflammatory pathways. The inflammatory outcome depends on the synthetic route used in the NPs production, in which toxic reagents are employed. In this work, we compared two types of Ag NPs, obtained by two different chemical routes: conventional synthesis using sodium citrate and a green protocol based on leaf extracts as a source of reduction and capping agents. A careful physicochemical characterization was carried out showing spherical and stable Ag NPs with an average size between 20 nm and 35 nm for conventional and green Ag NPs respectively. Then, we evaluated their ability to induce the activation of inflammation in Human Leukemic Monocytes (THP-1) differentiated into M0 macrophages using 1 µM and 2 µM NPs concentrations (corresponded to 0.1 µg/mL and 0.2 µg/mL respectively) and two-time points (24 h and 48 h). Our results showed a clear difference in Nuclear Factor κB (NF-κb) activation, Interleukins 6–8 (IL-6, IL-8) secretion, Tumor Necrosis Factor-α (TNF-α) and Cyclooxygenase-2 (COX-2) expression exerted by the two kinds of Ag NPs. Green Ag NPs were definitely tolerated by macrophages compared to conventional Ag NPs which induced the activation of all the factors mentioned above. Subsequently, the exposure of breast cancer cell line (MCF-7) to the green Ag NPs showed that they exhibited antitumor activity like the conventional ones, but surprisingly, using the MCF-10A line (not tumoral breast cells) the green Ag NPs did not cause a significant decrease in cell viability.
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Matsuda, Kazuhiko. "Chemical and biological studies of natural and synthetic products for the highly selective control of pest insect species". Bioscience, Biotechnology, and Biochemistry 86, nr 1 (25.10.2021): 1–11. http://dx.doi.org/10.1093/bbb/zbab187.
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ABSTRACT Tanacetum cinerariifolium was known to produce pyrethrins, but the mechanism of pyrethrin biosynthesis was largely unclear. The author showed that the nonmevalonate and oxylipin pathways underlie biosynthesis of the acid and alcohol moieties, respectively, and a GDSL lipase joins the products of these pathways. A blend of the green leaf volatiles and (E)-β-farnesene mediates the induction of wounding responses to neighboring intact conspecies by enhancing pyrethrin biosynthesis. Plants fight against herbivores underground as well as aboveground, and, in soy pulps, some fungi produce compounds selectively modulating ion channels in insect nervous system. The author proposed that indirect defense of plants occurs where microorganisms produce defense substances in the rhizosphere. Broad-spectrum pesticides, including neonicotinoids, may affect nontarget organisms. The author discovered cofactors enabling functional expression of insect nicotinic acetylcholine receptors (nAChRs). This led to understanding the mechanism of insect nAChR–neonicotinoid interactions, thus paving new avenues for controlling crop pests and disease vectors.
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Leite, Marina M., i Flavio M. Vichi. "Influence of synthesis route on the morphology of SrTiO3 particles". MRS Proceedings 1552 (2013): 51–57. http://dx.doi.org/10.1557/opl.2013.967.
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ABSTRACTThe cubic perovskite SrTiO3 is an important semiconductor oxide with a band gap of 3.2 eV. It has a wide variety of applications such as: dielectric materials, photoluminescent devices, and in photocatalysis. It is conventionally obtained by the classic solid state synthesis (SS), in which TiO2 and SrCO3 react for several hours at temperatures as high as 1200 °C. Besides the high energy demand, SS is not useful for the control of physical characteristics, such as particle size and morphology, which has become essential for some of its applications. It is known that many soft and green routes can produce SrTiO3. Among them, the hydrothermal (HT) and sol-precipitation (SP) methods, as well as the molten salt synthesis (MS) are interesting not only due to their low cost and energy use, but also because of the possibility of particle size and shape control. This study compares the size and morphology of the SrTiO3 particles obtained by these three synthetic pathways. Scanning electron microscopy (SEM) was used to compare particle size and morphology, and X-ray diffraction (XRD) was used to confirm the perovskite formation as well as to determine the Scherrer’s particle size.
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Martin, J. Lemuel, i S. Viswanathan. "Feasibility of Green Hydrogen-Based Synthetic Fuel as a Carbon Utilization Option: An Economic Analysis". Energies 16, nr 17 (4.09.2023): 6399. http://dx.doi.org/10.3390/en16176399.
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Singapore has committed to achieving net zero emissions by 2050, which requires the pursuit of multiple decarbonization pathways. CO2 utilization methods such as fuel production may provide a fast interim solution for carbon abatement. This paper evaluates the feasibility of green hydrogen-based synthetic fuel (synfuel) production as a method for utilizing captured CO2. We consider several scenarios: a baseline scenario with no changes, local production of synfuel with hydrogen imports, and overseas production of synfuel with CO2 exports. This paper aims to determine a CO2 price for synfuel production, evaluate the economic viability of local versus overseas production, and investigate the effect of different cost parameters on economic viability. Using the current literature, we estimate the associated production and transport costs under each scenario. We introduce a CO2 utilization price (CUP) that estimates the price of utilizing captured CO2 to produce synfuel, and an adjusted CO2 utilization price (CCUP) that takes into account the avoided emissions from crude oil-based fuel production. We find that overseas production is more economically viable compared to local production, with the best case CCUP bounds giving a range of 142–148 $/tCO2 in 2050 if CO2 transport and fuel shipping costs are low. This is primarily due to the high cost of hydrogen feedstock, especially the transport cost, which can offset the combined costs of CO2 transport and fuel shipping. In general, we find that any increase in the hydrogen feedstock cost can significantly affect the CCUP for local production. Sensitivity analysis reveals that hydrogen transport cost has a significant impact on the viability of local production and if this cost is reduced significantly, local production can be cheaper than overseas production. The same is true if the economies of scale for local production is significantly better than overseas production. A significantly lower carbon capture cost can also the reduce the CCUP significantly.
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Kost, Christoph, Julian Brandes, Charlotte Senkpiel, Philip Sterchele, Daniel Wrede i Hans-Martin Henning. "Modeling of Persistence, Non-Acceptance and Sufficiency in Long-Term Energy Scenarios for Germany". Energies 14, nr 15 (24.07.2021): 4484. http://dx.doi.org/10.3390/en14154484.
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Long-term transition pathways to a low-carbon energy system are analysed by applying the energy system model REMod. All in all, the paper contributes to the current research through an innovative scenario approach, using assumptions for societal trends and quantitative results for scenarios, analysing the paths towards climate neutrality and defossilization in 2050. In the case study of Germany, these trends and drivers influence the results and the technology composition in each consumption sector (buildings, transport, and industry). Across all scenarios, it can be observed that the electrification of all sectors is important for the defossilization of the energy system, as the direct use of electricity from renewable energy is more efficient than the consumption of carbon-neutral synthetic energy carriers. However, different consumer behavior (e.g., non-acceptance or resistance against specific technologies) influences not only the efficient use of (green) electricity, it also changes the optimal pathways of the transition to paths with greater efforts. One potential societal trend—sufficiency—could be an important cornerstone for reaching the targets, as the required expansion and exchange of technologies are lower and thus facilitate the transition.
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Mouhib, Mohammed, Melania Reggente, Lin Li, Nils Schuergers i Ardemis Anoush Boghossian. "Engineering Extracellular Electron Transfer in Escherichia coli for Microbial Electrochemical Devices". ECS Meeting Abstracts MA2022-01, nr 43 (7.07.2022): 1857. http://dx.doi.org/10.1149/ma2022-01431857mtgabs.
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Microbes hold great potential for green electrochemical synthesis as well as bio-electricity generation from organic waste. The key to the successful development of microbial electrochemical devices lies with the ability of the microbes to transport electrons across their outer membranes. These devices thus often rely on the use of microbes known as exoelectrogens, which include bacteria that have evolved metabolic pathways that enable extracellular electron transfer (EET) to solid substrates for cellular respiration. While exoelectrogens demonstrate facilitated electron transfer with the electrodes of these devices, natural exoelectrogens are often restricted to utilizing a narrow range of substrates that limits their versatility for processing different organic wastes and electrosynthesizing a rich diversity of high-value chemicals. By contrast, non-exoelectrogenic microbes such as Escherichia coli that lack efficient EET pathways are host to rich metabolic reaction networks that can be more readily tailored for various applications using synthetic biology. In this work, we biologically engineer E. coli for enhanced EET. To this end, we expressed different combinations of proteins from the natural exoelectrogen S. oneidensis MR-1, as well as E. coli native proteins to optimize EET of the bioengineered strain. The bioengineered strains show significant improvements in electron transfer rates, as confirmed through colorimetric reduction assays of soluble electron acceptors and electrochemical characterizations following electrode reduction. The improved EET demonstrated in this work paves the way for increasing the efficiency of existing E. c oli - based electrochemical devices while opening the doors to new applications that benefit from the broad chemical repertoire of these microbes.
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Murray, Janet M., i Douglas I. Johnson. "Isolation and Characterization of Nrf1p, a Novel Negative Regulator of the Cdc42p GTPase in Schizosaccharomyces pombe". Genetics 154, nr 1 (1.01.2000): 155–65. http://dx.doi.org/10.1093/genetics/154.1.155.
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Abstract The Cdc42p GTPase and its regulators, such as the Saccharomyces cerevisiae Cdc24p guanine-nucleotide exchange factor, control signal-transduction pathways in eukaryotic cells leading to actin rearrangements. A cross-species genetic screen was initiated based on the ability of negative regulators of Cdc42p to reverse the Schizosaccharomyces pombe Cdc42p suppression of a S. cerevisiae cdc24ts mutant. A total of 32 S. pombe nrf (negative regulator of Cdc forty two) cDNAs were isolated that reversed the suppression. One cDNA, nrf1+, encoded an ~15 kD protein with three potential transmembrane domains and 78% amino-acid identity to a S. cerevisiae gene, designated NRF1. A S. pombe Δnrf1 mutant was viable but overexpression of nrf1+ in S. pombe resulted in dose-dependent lethality, with cells exhibiting an ellipsoidal morphology indicative of loss of polarized cell growth along with partially delocalized cortical actin and large vacuoles. nrf1+ also displayed synthetic overdose phenotypes with cdc42 and pak1 alleles. Green fluorescent protein (GFP)-Cdc42p and GFP-Nrf1p colocalized to intracellular membranes, including vacuolar membranes, and to sites of septum formation during cytokinesis. GFP-Nrf1p vacuolar localization depended on the S. pombe Cdc24p homolog Scd1p. Taken together, these data are consistent with Nrf1p functioning as a negative regulator of Cdc42p within the cell polarity pathway.
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Ogbe, Emmanuel, Ali Almansoori, Michael Fowler i Ali Elkamel. "Optimizing Renewable Injection in Integrated Natural Gas Pipeline Networks Using a Multi-Period Programming Approach". Energies 16, nr 6 (10.03.2023): 2631. http://dx.doi.org/10.3390/en16062631.
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In this paper, we propose an optimization model that considers two pathways for injecting renewable content into natural gas pipeline networks. The pathways include (1) power-to-hydrogen or PtH, where off-peak electricity is converted to hydrogen via electrolysis, and (2) power-to-methane, or PtM, where carbon dioxide from different source locations is converted into renewable methane (also known as synthetic natural gas, SNG). The above pathways result in green hydrogen and methane, which can be injected into an existing natural gas pipeline network. Based on these pathways, a multi-period network optimization model that integrates the design and operation of hydrogen from PtH and renewable methane is proposed. The multi-period model is a mixed-integer non-linear programming (MINLP) model that determines (1) the optimal concentration of hydrogen and carbon dioxide in the natural gas pipelines, (2) the optimal location of PtH and carbon dioxide units, while minimizing the overall system cost. We show, using a case study in Ontario, the optimal network structure for injecting renewable hydrogen and methane within an integrated natural gas network system provides a $12M cost reduction. The optimal concentration of hydrogen ranges from 0.2 vol % to a maximum limit of 15.1 vol % across the network, while reaching a 2.5 vol % at the distribution point. This is well below the maximum limit of 5 vol % specification. Furthermore, the optimizer realized a CO2 concentration ranging from 0.2 vol % to 0.7 vol %. This is well below the target of 1% specified in the model. The study is essential to understanding the practical implication of hydrogen penetration in natural gas systems in terms of constraints on hydrogen concentration and network system costs.
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Molden, Brent M., Kimberly A. Cooney, Kirk West, Lex H. T. Van Der Ploeg i Giulia Baldini. "Temporal cAMP Signaling Selectivity by Natural and Synthetic MC4R Agonists". Molecular Endocrinology 29, nr 11 (1.11.2015): 1619–33. http://dx.doi.org/10.1210/me.2015-1071.
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Abstract The melanocortin-4 receptor (MC4R) is a G protein-coupled receptor expressed in the brain, where it controls energy balance through pathways including α-melanocyte-stimulating hormone (α-MSH)-dependent signaling. We have reported that the MC4R can exist in an active conformation that signals constitutively by increasing cAMP levels in the absence of receptor desensitization. We asked whether synthetic MC4R agonists differ in their ability to increase intracellular cAMP over time in Neuro2A cells expressing endogenous MC4R and exogenous, epitope-tagged hemagglutinin-MC4R-green fluorescent protein. By analyzing intracellular cAMP in a temporally resolved Förster resonance energy transfer assay, we show that withdrawal of α-MSH leads to a quick reversal of cAMP induction. By contrast, the synthetic agonist melanotan II (MTII) induces a cAMP signal that persists for at least 1 hour after removal of MTII from the medium and cannot be antagonized by agouti related protein. Similarly, in mHypoE-42 immortalized hypothalamic neurons, MTII, but not α-MSH, induced persistent AMP kinase signal, which occurs downstream of increased cAMP. By using a fluorescence recovery after photobleaching assay, it appears that the receptor exposed to MTII continues to signal after being internalized. Similar to MTII, the synthetic MC4R agonists, THIQ and BIM-22511, but not LY2112688, induced prolonged cAMP signaling after agonist withdrawal. However, agonist-exposed MC4R desensitized to the same extent, regardless of the ligand used and regardless of differences in receptor intracellular retention kinetics. In conclusion, α-MSH and LY2112688, when compared with MTII, THIQ, and BIM-22511, vary in the duration of the acute cAMP response, showing distinct temporal signaling selectivity, possibly linked to specific cell compartments from which cAMP signals may originate.
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Komalavilas, Padmini, Raymond B. Penn, Charles R. Flynn, Jeffrey Thresher, Luciana B. Lopes, Elizabeth J. Furnish, Manhong Guo, Manuel A. Pallero, Joanne E. Murphy-Ullrich i Colleen M. Brophy. "The small heat shock-related protein, HSP20, is a cAMP-dependent protein kinase substrate that is involved in airway smooth muscle relaxation". American Journal of Physiology-Lung Cellular and Molecular Physiology 294, nr 1 (styczeń 2008): L69—L78. http://dx.doi.org/10.1152/ajplung.00235.2007.
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Activation of the cAMP/cAMP-dependent PKA pathway leads to relaxation of airway smooth muscle (ASM). The purpose of this study was to examine the role of the small heat shock-related protein HSP20 in mediating PKA-dependent ASM relaxation. Human ASM cells were engineered to constitutively express a green fluorescent protein-PKA inhibitory fusion protein (PKI-GFP) or GFP alone. Activation of the cAMP-dependent signaling pathways by isoproterenol (ISO) or forskolin led to increases in the phosphorylation of HSP20 in GFP but not PKI-GFP cells. Forskolin treatment in GFP but not PKI-GFP cells led to a loss of central actin stress fibers and decreases in the number of focal adhesion complexes. This loss of stress fibers was associated with dephosphorylation of the actin-depolymerizing protein cofilin in GFP but not PKI-GFP cells. To confirm that phosphorylated HSP20 plays a role in PKA-induced ASM relaxation, intact strips of bovine ASM were precontracted with serotonin followed by ISO. Activation of the PKA pathway led to relaxation of bovine ASM, which was associated with phosphorylation of HSP20 and dephosphorylation of cofilin. Finally, treatment with phosphopeptide mimetics of HSP20 possessing a protein transduction domain partially relaxed precontracted bovine ASM strips. In summary, ISO-induced phosphorylation of HSP20 or synthetic phosphopeptide analogs of HSP20 decreases phosphorylation of cofilin and disrupts actin in ASM, suggesting that one possible mechanism by which HSP20 mediates ASM relaxation is via regulation of actin filament dynamics.
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Kamli, Majid Rasool, Vartika Srivastava, Nahid H. Hajrah, Jamal S. M. Sabir, Arif Ali, Maqsood Ahmad Malik i Aijaz Ahmad. "Phytogenic Fabrication of Ag–Fe Bimetallic Nanoparticles for Cell Cycle Arrest and Apoptosis Signaling Pathways in Candida auris by Generating Oxidative Stress". Antioxidants 10, nr 2 (27.01.2021): 182. http://dx.doi.org/10.3390/antiox10020182.
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Novel green synthetic nanomedicines have been recognized as alternative therapies with the potential to be antifungal agents. Apoptosis induction, cell cycle arrest and activation of the antioxidant defense system in fungal cells have also gained attention as emerging drug targets. In this study, a facile and biodegradable synthetic route was developed to prepare Ag–Fe bimetallic nanoparticles using aqueous extract of Beta vulgaris L. Surface plasmon resonance of Beta vulgaris-assisted AgNPs nanoparticles was not observed in the UV-visible region of Ag–Fe bimetallic NPs, which confirms the formation of Ag–Fe nanoparticles. Beta vulgaris-assisted Ag–Fe NPs were characterized by FTIR spectroscopy, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction and TGA-DTG analysis for their structural and morphological properties. The as-prepared Ag–Fe NPs were well dispersed and spherical with the average particle size of 15 nm. The antifungal activity of these Ag–Fe NPs against clinical isolates of Candida auris was determined by broth microdilution and cell viability assays. For insights into mechanisms, induction of apoptosis and triggering cell cycle arrest were studied following standard protocols. Furthermore, analysis of antioxidant defense enzymes was determined spectrophotometrically. Antifungal susceptibility results revealed high antifungal activity with MIC values ranging from 0.19 to 0.39 µg/mL. Further studies showed that Ag–Fe NPs were able to induce apoptosis, cell cycle arrest in G2/M phase and disturbances in primary and secondary antioxidant enzymes. This study presents the potential of Ag–Fe NPs to inhibit and potentially eradicate C. auris by inducing apoptosis, cell cycle arrest and increased levels of oxidative stress.
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Mellor, Silas Busck, James B. Y. H. Behrendorff, Agnieszka Zygadlo Nielsen, Poul Erik Jensen i Mathias Pribil. "Non-photosynthetic plastids as hosts for metabolic engineering". Essays in Biochemistry 62, nr 1 (27.02.2018): 41–50. http://dx.doi.org/10.1042/ebc20170047.
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Using plants as hosts for production of complex, high-value compounds and therapeutic proteins has gained increasing momentum over the past decade. Recent advances in metabolic engineering techniques using synthetic biology have set the stage for production yields to become economically attractive, but more refined design strategies are required to increase product yields without compromising development and growth of the host system. The ability of plant cells to differentiate into various tissues in combination with a high level of cellular compartmentalization represents so far the most unexploited plant-specific resource. Plant cells contain organelles called plastids that retain their own genome, harbour unique biosynthetic pathways and differentiate into distinct plastid types upon environmental and developmental cues. Chloroplasts, the plastid type hosting the photosynthetic processes in green tissues, have proven to be suitable for high yield protein and bio-compound production. Unfortunately, chloroplast manipulation often affects photosynthetic efficiency and therefore plant fitness. In this respect, plastids of non-photosynthetic tissues, which have focused metabolisms for synthesis and storage of particular classes of compounds, might prove more suitable for engineering the production and storage of non-native metabolites without affecting plant fitness. This review provides the current state of knowledge on the molecular mechanisms involved in plastid differentiation and focuses on non-photosynthetic plastids as alternative biotechnological platforms for metabolic engineering.
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Stephenson, Michael J., i Anne Osbourn. "Making drugs out of sunlight and ‘thin air’: an emerging synergy of synthetic biology and natural product chemistry". Biochemist 42, nr 4 (29.07.2020): 34–39. http://dx.doi.org/10.1042/bio20200044.
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Nature has long served as a rich source of structurally diverse small organic molecules with medicinally relevant biological activities. Despite the historical success of these so-called natural products, the enthusiasm of big pharma to explore these compounds as leads in drug design has waxed and waned. A major contributor to this is their often inherent structural complexity. Such compounds are difficult (often impossible) to access synthetically, a hurdle that can stifle lead development and hinder sustainable large-scale production of promising leads for clinical evaluation. However, in recent years, an emerging synergy between synthetic biology and natural product chemistry offers the potential for a renaissance in our ability to access natural products for drug discovery and development. Advances in genome sequencing, bioinformatics and the maturing of heterologous expression platforms are increasing, enabling the study, and ultimately, the manipulation of plant biosynthetic pathways. The triterpenes are one of the most structurally diverse families of natural products and arguably one of the most underrepresented in the clinic. The plant kingdom is the richest source of triterpene diversity, with >20,000 triterpenes reported so far. Transient expression of genes for candidate enzymes and pathways in amenable plant species is emerging as a powerful and rapid means of investigating and harnessing the plant enzymes involved in generating this diversity. Such platforms also have the potential to serve as production systems in their own right, with the possibility of upscaling these discoveries into commercially useful products using the same overall basic procedure. Ultimately, the carbon source for generation of high-value compounds in plants is photosynthesis. Therefore, we could, with the help of plants, be producing new medicines out of sunlight and ‘thin air’ in green factories in the not too distant future.
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Filippi, Alexandru, Oana-Alina Ciolac, Constanța Ganea i Maria-Magdalena Mocanu. "ErbB Proteins as Molecular Target of Dietary Phytochemicals in Malignant Diseases". Journal of Oncology 2017 (2017): 1–20. http://dx.doi.org/10.1155/2017/1532534.
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ErbB proteins overexpression, in both normal and mutated forms, is associated with invasive forms of cancer prone to metastasis and with stronger antiapoptotic mechanisms and therefore more challenging to treat. Downstream effectors of ErbB receptors mediating these phenotypic traits include MAPK, STAT, and PI3K/AKT/mTOR pathways. Various phytochemical compounds were studied for their large number of biological effects including anticancer activity. Among these compounds, epigallocatechin-3-gallate (EGCG), the main catechin from green tea leaves, and curcumin, component of the curry powder, constituted the object of numerous studies. Both compounds were shown to act directly either on ErbB expression, or on their downstream signaling molecules. In this paper we aim to review the involvement of ErbB proteins in cancer as well as the biologic activity of EGCG and curcumin in ErbB expressing and overexpressing malignancies. The problems arising in the administration of the two compounds due to their reduced bioavailability when orally administered, as well as the progress made in this field, from using novel formulations to improved dosing regimens or improved synthetic analogs, are also discussed.
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Shaheen, Saman, Syed Asim Ali, Umar Farooq Mir, Iqra Sadiq i Tokeer Ahmad. "Recent Advances in Transition Metal Phosphide Nanocatalysts for H2 Evolution and CO2 Reduction". Catalysts 13, nr 7 (28.06.2023): 1046. http://dx.doi.org/10.3390/catal13071046.
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Green hydrogen energy has captivated researchers and is regarded as a feasible option for future energy-related aspirations. The emerging awareness of renewable energy-driven hydrogen generation and carbon dioxide reduction calls for the use of unconventional schematic tools in the fabrication of nanocatalyst systems. Transition metal phosphides are state-of-art, cost-effective, noble-metal-free materials that have been comprehensively examined for sustainable energy-driven applications. Recent reports on these advanced functional materials have cemented their candidature as high-performance catalytic systems for hydrogen production and for carbon dioxide conversion into value-added chemical feedstock. Bimetallic NiCoP (238.2 mmol g−1 h−1) exhibits top-notch catalytic competence toward photocatalytic HER that reveals the energy-driven application of a pristine class of TMPs, whereas heterostructured Ni2P/CdS was found to be fit for photochemical CO2 reduction, as well as for HER. On the other hand, pristine Ni2P was recently ascertained as an efficient electrocatalytic system for HER and CO2RR applications. A wide array of physicochemical modulations, such as compositional and structural engineering, defect generation, and facet control, have been used for improving the catalytic efficiency of transition metal phosphide nanostructures. In this review, we succinctly discuss the proficiency of transition metal phosphides in green hydrogen production and carbon dioxide conversion via photochemical and electrochemical pathways. We detail the significance of their structural properties and brief the readers about the synthetic advancements without deviating from our goal of summarizing the recent achievements in energy-driven applications.
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Singh, Apurva Anand, Gunasekaran Rajeswari, Louis Anto Nirmal i Samuel Jacob. "Synthesis and extraction routes of allelochemicals from plants and microbes: A review". Reviews in Analytical Chemistry 40, nr 1 (1.01.2021): 293–311. http://dx.doi.org/10.1515/revac-2021-0139.
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Abstract Allelopathy, a complex phenomenon has unveiled both stimulatory and inhibitory effects in plant processes that are mediated by the release of certain chemical compounds commonly known as allelochemicals. Allelochemicals, a form of bioactive secondary metabolites are produced by a diverse group of plants and microbes in response to biotic and abiotic stress. It ranges from a simple hydrocarbon to complex polycyclic aromatic compounds like phenol, flavonoids, tannins, steroids, amino acids, alkaloids and quinones. These plant bioactive compounds are released into the environment via decomposition, exudation, leaching and volatilization that play a significant role in regulating the intra-specific or inter-specific relations with counterparts. A wide variety of methods has been proposed for analyzing the basic mechanism and overall effect of allelochemicals. However, the lack of a reliable and effective method to identify their molecular mode of action and their modulation in the metabolic pathway still remains as a great challenge. From a commercial perspective, these allelochemicals are deemed to be better candidates for green natural herbicides and weedicides that are proven to be environment friendly, unlike synthetic chemicals. In order to pave a way for the economic viability of these chemicals, a basic understanding of their chemistry is inevitable. This review article is focused to give an in-depth understanding of metabolic pathways genes responsible for the elicitation/secretion and the adoption of a suitable downstream process and analytical techniques that can intensify the process.
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Marchetto, Francesca, Marco Roverso, Davide Righetti, Sara Bogialli, Francesco Filippini, Elisabetta Bergantino i Eleonora Sforza. "Bioremediation of Per- and Poly-Fluoroalkyl Substances (PFAS) by Synechocystis sp. PCC 6803: A Chassis for a Synthetic Biology Approach". Life 11, nr 12 (26.11.2021): 1300. http://dx.doi.org/10.3390/life11121300.
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One of the main concerns in industrialized countries is represented by per- and poly-fluoroalkyl substances (PFAS), persistent contaminants hardly to be dealt with by conventional wastewater treatment processes. Phyco-remediation was proposed as a green alternative method to treat wastewater. Synechocystis sp. PCC6803 is a unicellular photosynthetic organism candidate for bioremediation approaches based on synthetic biology, as it is able to survive in a wide range of polluted waters. In this work, we assessed the possibility of applying Synechocystis in PFAS-enriched waters, which was never reported in the previous literature. Respirometry was applied to evaluate short-term toxicity of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), which did not affect growth up to 0.5 and 4 mg L−1, respectively. Continuous and batch systems were used to assess the long-term effects, and no toxicity was highlighted for both compounds at quite high concentration (1 mg L−1). A partial removal was observed for PFOS and PFOA, (88% and 37%, with removal rates of about 0.15 and 0.36 mg L−1 d−1, respectively). Measurements in fractionated biomass suggested a role for Synechocystis in the sequestration of PFAS: PFOS is mainly internalized in the cell, while PFOA is somehow transformed by still unknown pathways. A preliminary bioinformatic search gave hints on transporters and enzymes possibly involved in such sequestration/transformation processes, opening the route to metabolic engineering in the perspective application of this cyanobacterium as a new phyco-remediation tool, based on synthetic biology.
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TOMULESCU, CATERINA, MIȘU MOSCOVICI, IRINA LUPESCU, ROXANA MĂDĂLINA STOICA i ADRIAN VAMANU. "A Review: Klebsiella pneumoniae, Klebisellaoxytoca and Biotechnology". Romanian Biotechnological Letters 26, nr 3 (11.04.2021): 2567–86. http://dx.doi.org/10.25083/rbl/26.3/2567.2586.
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Biotechnology, molecular biology and genetic engineering, and bioprospecting play a crucial role in our common future, enabling industrially important microorganisms to ensure sustainable products (fuels, chemicals, pharmaceuticals, food, drug delivery systems, medical devices etc.) and new bioeconomic opportunities. Biotechnological applications are able to provide cost-effective green alternatives to conventional industrial processes, which are currently affecting the nature and biodiversity. Klebsiella species are among the well-studied microbes both in medicine field, as ones of the most resilient opportunistic pathogens, and in industry, due to their promising biochemical properties, and their potential as better hosts than other microorganisms, for i.e. in genetic manipulation. Klebsiella oxytoca and Klebsiella pneumoniae are ubiquitously found in natural environments, but also as commensals in the human gut, and associated with a high-resistance to the first-line antibiotics. However, these specific strains are continuously isolated and studied for different industrial purposes (i.e. bulk chemicals and biofuels production, medical diagnosis, nanoparticles and exopolysaccharides synthesis, plant growth promoting activities, bioremediation and biodegradation agents etc.), and scientific results regarding their biotechnological potential could generate big impact for global bioeconomy development. Recently, research in synthetic biology gained a lot of attention, and new techniques highlight ways to reprogramme these microbial cells in view of high-yield or high-quality new chemicals obtainment. Therefore, some scientific research niches are emerging in biotechnology, and unknown metabolic pathways and genes are identified and further studied, to provide alternative solutions to the global challenges.
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Xu, Xueyan, Jun Gao, Zhonghao Zhang i Jing Fu. "An Assessment of Chinese Pathways to Implement the UN Sustainable Development Goal-11 (SDG-11)—A Case Study of the Yangtze River Delta Urban Agglomeration". International Journal of Environmental Research and Public Health 16, nr 13 (28.06.2019): 2288. http://dx.doi.org/10.3390/ijerph16132288.
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Urban sustainability is a crucial part of the United Nations (UN) Sustainable Development Goals (SDGs) and one of the core objectives of China’s national strategy to promote new urbanization and achieve integration in the Yangtze River Delta (YRD). This paper mainly focused on the 11th SDG, which is a universal call to make cities and human settlements inclusive, safe, resilient and sustainable. The full permutation polygon synthetic indicator (FPPSI) method was applied to synthetically evaluate the sustainable level of 26 cities in the YRD urban agglomeration from 2007 to 2016. The results showed that: (1) the synthesis indicators were increasing year by year, which implied that the sustainable development of the YRD has shown obvious progress in recent years. However, each city faced its own challenges to achieving the sustainable development goals. The sustainability level for the majority of cities was restricted by obstacles such as the per capita green area, air quality and commercial housing sales area; (2) Among the 26 cities, small and medium-sized cities were subject to the traditional strong sustainability indicators while large and mega cities were more affected by weak sustainability indicators; (3) Spatial differences were found for the overall sustainable development level of the YRD. The diffusion and assembly effect among cities had not yet been formed; however, the strong spillover effect of developed cities might influence the ability of other cities to achieve sustainable development goals in many aspects of the environment, economy and society. The results suggest the need for a stronger focus on improving regional developing patterns and strengthening coordination in the process of achieving the sustainable development goal of urban agglomeration in the YRD. Furthermore, according to the conditions of different cities, integrated policies are required to address all aspects of sustainability and to avoid unintended consequences.
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Gao, Yang, Wei Xiong, Ming J. He, Li Tang, Jin Y. Xiang i Qing Y. Wu. "Action Spectra of Chlorophyll a Biosynthesis in Cyanobacteria: Dark-Operative Protochlorophyllide Oxidoreductase-Deficient Mutants". Zeitschrift für Naturforschung C 64, nr 1-2 (1.06.2009): 117–24. http://dx.doi.org/10.1515/znc-2009-1-219.
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Both light-dependent and light-independent (dark) protochlorophyllide (Pchlide) reductase account for catalyzing the reduction of Pchlide to chlorophyllide during the biosynthesis of Mg-tetrapyrrole pigments in cyanobacteria. To gain more insight into the interaction between the wavelength of the light and these two chlorophyll synthetic pathways in Synechocystis sp. PCC 6803, the spectral effectiveness of the formation of chlorophyll a was investigated during the regreening process in chlL- and chlN- mutants, which could not synthesize chlorophyll during growth in the dark. The action spectra showed obvious maxima around 450 nm and 650 nm, similar to those of higher plants except that the intensities of two peaks are reversed. The mRNA levels of chlL and chlN and chlorophyll a content under different wavelengths of light in the wild-type strain were also measured. The RT-PCR analysis revealed that the transcripts of chlL and chlN were up-regulated in red light but simultaneously down-regulated in green light which resulted in corresponding changes of the chlorophyll content. This fact indicates that the regulation of dark-operative protochlorophyllide oxidoreductase (DPOR) in the transcriptional level is essential for cyanobacteria to synthesize appropriate chlorophyll for acclimating in various light colour environments.