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Artykuły w czasopismach na temat "Lipophilic Groups"
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Gaddale Devanna, Kishore K., Justyna M. Gawel, Tracy A. Prime, Filip Cvetko, Cristiane Benincá, Stuart T. Caldwell, Alexander Negoda i in. "Tetra-arylborate lipophilic anions as targeting groups". Chemical Communications 57, nr 25 (2021): 3147–50. http://dx.doi.org/10.1039/d0cc07924c.
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Madak, Joseph, i Nouri Neamati. "Membrane Permeable Lipophilic Cations as Mitochondrial Directing Groups". Current Topics in Medicinal Chemistry 15, nr 8 (13.03.2015): 745–66. http://dx.doi.org/10.2174/1568026615666150302105622.
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Koval'ov, N., I. Kuznetsova, E. Burakova, V. Sil'nikov, M. Zenkova i V. Vlassov. "Ribonuclease Activity of Cationic Structures Conjugated to Lipophilic Groups". Nucleosides, Nucleotides and Nucleic Acids 23, nr 6-7 (31.12.2004): 977–81. http://dx.doi.org/10.1081/ncn-200026050.
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Villanueva, María Emilia, Ana Salinas, Joaquín Antonio González, Sergio Teves i Guillermo Javier Copello. "Dual antibacterial effect of immobilized quaternary ammonium and aliphatic groups on PVC". New Journal of Chemistry 39, nr 12 (2015): 9200–9206. http://dx.doi.org/10.1039/c5nj01766a.
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Gasiorowski, J., N. Pootrakulchote, C. Reanprayoon, K. Jaisabuy, P. Vanalabhpatana, N. S. Sariciftci i P. Thamyongkit. "Porphyrin containing lipophilic amide groups as a photosensitizer for dye-sensitized solar cells". RSC Advances 5, nr 89 (2015): 72900–72906. http://dx.doi.org/10.1039/c5ra10538b.
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Zhao, Changming, Yulian Jiang, Mengwei Li, Tiexin Cheng, Wensheng Yang i Guangdong Zhou. "The effect of NaOH on lowering interfacial tension of oil/alkylbenzene sulfonates solution". RSC Advances 8, nr 11 (2018): 6169–77. http://dx.doi.org/10.1039/c7ra11287d.
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The increase of NaOH concentration resulted in the compression of the electrical double layer. The distribution of PDABS in the oil phase improved the mutual attraction of lipophilic chains and the close-packed lipophilic groups at the interface.
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Czech, Bronislaw P., Anna Czech, Byungki Son, Han Koo Lee i Richard A. Bartsch. "Synthesis of lipophilic crown ethers with pendant carboxylic acid groups". Journal of Heterocyclic Chemistry 23, nr 2 (marzec 1986): 465–71. http://dx.doi.org/10.1002/jhet.5570230231.
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Kong, Xiangjun, Junhe Zhao, Lijun Zhang, Zupei Liang i Jinlan Wang. "Design, synthesis and characterization of bitumen emulsifiers based on molecular simulation". Kemija u industriji 68, nr 1-2 (2019): 1–6. http://dx.doi.org/10.15255/kui.2018.013.
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Under the guidance of molecular simulation technology, the Monte Carlo molecular mechanics simulation was used to calculate the compatibility of different lipophilic groups with each component of bitumen, and the compatibility of different hydrophilic groups with water. Based on the calculated results of interaction parameters Chi and mixture energy Emix, the preferred structures of lipophilic and hydrophilic groups of bitumen emulsifier were determined. The target bitumen emulsifier was then synthesized by the reaction of organic acid and polyamine. The molecular simulation results showed that the compatibility of lipophilic group T11 with the bitumen was the best, and the mixing ability of the hydrophilic group H5 with water was excellent. The experimental results show that the preferred structures T11H5 had a good emulsifying performance to prepare emulsified bitumen with good storage stability, consistent with the results of the molecular simulation.
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Degtyareva, Ekaterina Aleksandrovna, Liliya Ivanovna Vyshnevska, Svetlana Vasil'yevna Garnaya i Ekaterina Aleksandrovna Kalko. "THE STUDY OF PHYSICO-TECHNOLOGICAL FACTORS’ INFLUENCE ON THE OUTPUT OF LIPOPHILIC SUB-STANCES FROM MEDICINAL PLANT MATERIALS". chemistry of plant raw material, nr 3 (7.04.2019): 299–305. http://dx.doi.org/10.14258/jcprm.2019035098.
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Currently, the lipophilic fractions of well-known medicinal plants are still understudied despite of contains of unique groups of BAS (chlorophylls, carotenoids, tocopherols, sterols, unsaturated fatty acids, phospholipids, etc.), what is the actual task of modern pharmaceutical science.
The aim of our work was to perform experimental studies for the choice of optimal conditions of the extraction of lipophilic compounds from the meal of pumpkin pulp.
Extraction of lipophilic substances from the meal of pumpkin pulp was carried out in laboratory conditions in the Soxhlet apparatus by the method of circulation extraction. The weight loss on drying, the content of extractive lipophilic substances and the amount of carotenoids (in terms of β-carotene) were determined by compendial procedures.
According to the results of the experimental work, the optimum humidity (not more than 7%) and drying temperature (+ 60 °C) of pumpkin pulp meal containing carotenoids were established. The obtained data are necessary for the development of technology of lipophilic pumpkin extract.
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Reichardt, Christian, Stefan Löbbecke, Abdol Mohammed Mehranpour i Gerhard Schäfer. "Pyridinium N-phenoxide betaines and their application to the determination of solvent polarities, XXIV. Syntheses and UV-vis spectroscopic properties of new lipophilic tert-butyl- and 1-adamantyl substituted, negatively solvatochromic pyridinium N-phenolate betaine dyes". Canadian Journal of Chemistry 76, nr 6 (1.06.1998): 686–94. http://dx.doi.org/10.1139/v98-019.
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Syntheses and negative solvatochromism of two new lipophilic pentaphenyl pyridinium N-phenolate betaine dyes, substituted with seven tert-butyl groups (9) or with three tert-butyl and two 1-adamantyl groups (13) in the peripheral phenyl rings, are described in order to get zwitterionic dyes that are more soluble in nonpolar solvents such as the standard betaine dye, 1, which has been used for the construction of an empirical scale of solvent polarity, called the ET(30) scale.Key words: betaine dyes, ET(30) values, lipophilic dyes, pyridinium N-phenolate betaine dyes, solvatochromism, solvent polarity.
Rozprawy doktorskie na temat "Lipophilic Groups"
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Quader, Sabina, i N/A. "Selective Synthetic Modification of Aminoglycosides for Drug Targeting to Tuberculosis". Griffith University. School of Biomolecular and Physical Sciences, 2007. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20071024.151619.
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The work presented in this thesis details the synthetic modification of the clinically important aminoglycoside antibiotics, neomycin B, paromomycin and tobramycin. We sought to modify aminoglycosides by attaching lipophilic groups, including fatty acids and steroids, with a view to improving the bacterial membrane permeability of these species, and ultimately their efficacy in the treatment of tuberculosis. Our initial synthetic strategy involved direct and specific functionalization of the singular primary hydroxyl group of the aminoglycoside antibiotic neomycin B, with lipophilic groups containing carboxylic acid functions via Mitsunobu esterification. Although, direct and selective Mitsunobu acylation of the primary hydroxyl group proved unsuccessful in the case of the pseudo tetrasaccharide neomycin B, the Mitsunobu reaction did however result in selective chemistry elsewhere in the molecule and this has been exploited for modification of the ido (ring IV) and streptamine (ring II) ring systems. Under carefully controlled conditions, the Mitsunobu reaction has been used for the selective dehydration of the ido ring, to give the talo epoxide, and, under more forcing Mitsunobu dehydration conditions, an aziridine function has been introduced into the streptamine moiety. Both the epoxide and the epoxide-aziridine neomycin building blocks were utilized as synthons in subsequent chemical transformations. Seventeen novel neomycin derivatives featuring modification of ring IV and/or ring II were obtained using this approach. Explicit structural elucidation of all the synthetic intermediates and the final products was achieved using high temperature NMR spectroscopy. Direct and specific functionalization of the singular primary hydroxyl group at the C5 position of the ribose ring (ring III) of neomycin B was achieved, via a procedure based in part on selective tripsylation of the C5III primary hydroxyl group of neomycin B reported previously, followed by subsequent displacement of the tripsyl group by azide. Terminal alkyne containing lipophilic esters were then successfully attached to the ribose residue of neomycin B via Cu(I)-mediated azide-alkyne coupling reaction. In addition to the isolation of two fortuitous, new and versatile synthons i.e. monoanhydro neomycin and bis-anhydro neomycin for modification of ring IV and ring II of neomycin, a third synthon based on neomycin framework, allowing stepwise modification of ring III and ring IV was designed and synthesized. This synthon features an epoxide function in the ido ring, and a protected amine function at the C5 position of the ribose ring. Examples of the stepwise use of this synthon for further synthetic modification of the neomycin framework were demonstrated. Fourteen novel neomycin derivatives featuring modification of ring III and /or ring IV were obtained and characterized. Regioselective Mitsunobu esterification of the single primary hydroxyl group of the pseudo trisaccharide tobramycin was utilized successfully to link a variety of hydrophobic esters with tobramycin. Nine lipophilic tobramycin derivatives with significant structural diversity were synthesised and characterized. In a preliminary study, the applicability of the Mitsunobu dehydration reaction for the regioselective formation of an epoxide ring in the ido moiety of the pseudo tetrasaccharide aminoglycoside antibiotic paromomycin system was confirmed. The regioselective ring-opening of the derived epoxide with azide at C3IV of paromomycin was also successfully demonstrated. In total, forty-two new potential aminoglycoside antibiotics have been synthesized and characterized.
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Quader, Sabina. "Selective Synthetic Modification of Aminoglycosides for Drug Targeting to Tuberculosis". Thesis, Griffith University, 2007. http://hdl.handle.net/10072/367086.
Pełny tekst źródłaStreszczenie:
The work presented in this thesis details the synthetic modification of the clinically important aminoglycoside antibiotics, neomycin B, paromomycin and tobramycin. We sought to modify aminoglycosides by attaching lipophilic groups, including fatty acids and steroids, with a view to improving the bacterial membrane permeability of these species, and ultimately their efficacy in the treatment of tuberculosis. Our initial synthetic strategy involved direct and specific functionalization of the singular primary hydroxyl group of the aminoglycoside antibiotic neomycin B, with lipophilic groups containing carboxylic acid functions via Mitsunobu esterification. Although, direct and selective Mitsunobu acylation of the primary hydroxyl group proved unsuccessful in the case of the pseudo tetrasaccharide neomycin B, the Mitsunobu reaction did however result in selective chemistry elsewhere in the molecule and this has been exploited for modification of the ido (ring IV) and streptamine (ring II) ring systems. Under carefully controlled conditions, the Mitsunobu reaction has been used for the selective dehydration of the ido ring, to give the talo epoxide, and, under more forcing Mitsunobu dehydration conditions, an aziridine function has been introduced into the streptamine moiety. Both the epoxide and the epoxide-aziridine neomycin building blocks were utilized as synthons in subsequent chemical transformations. Seventeen novel neomycin derivatives featuring modification of ring IV and/or ring II were obtained using this approach. Explicit structural elucidation of all the synthetic intermediates and the final products was achieved using high temperature NMR spectroscopy. Direct and specific functionalization of the singular primary hydroxyl group at the C5 position of the ribose ring (ring III) of neomycin B was achieved, via a procedure based in part on selective tripsylation of the C5III primary hydroxyl group of neomycin B reported previously, followed by subsequent displacement of the tripsyl group by azide.
Terminal alkyne containing lipophilic esters were then successfully attached to the ribose residue of neomycin B via Cu(I)-mediated azide-alkyne coupling reaction. In addition to the isolation of two fortuitous, new and versatile synthons i.e. monoanhydro neomycin and bis-anhydro neomycin for modification of ring IV and ring II of neomycin, a third synthon based on neomycin framework, allowing stepwise modification of ring III and ring IV was designed and synthesized. This synthon features an epoxide function in the ido ring, and a protected amine function at the C5 position of the ribose ring. Examples of the stepwise use of this synthon for further synthetic modification of the neomycin framework were demonstrated. Fourteen novel neomycin derivatives featuring modification of ring III and /or ring IV were obtained and characterized. Regioselective Mitsunobu esterification of the single primary hydroxyl group of the pseudo trisaccharide tobramycin was utilized successfully to link a variety of hydrophobic esters with tobramycin. Nine lipophilic tobramycin derivatives with significant structural diversity were synthesised and characterized. In a preliminary study, the applicability of the Mitsunobu dehydration reaction for the regioselective formation of an epoxide ring in the ido moiety of the pseudo tetrasaccharide aminoglycoside antibiotic paromomycin system was confirmed. The regioselective ring-opening of the derived epoxide with azide at C3IV of paromomycin was also successfully demonstrated. In total, forty-two new potential aminoglycoside antibiotics have been synthesized and characterized.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Biomolecular and Physical Sciences
Faculty of Science, Environment, Engineering and Technology
Full Text
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Zhuang, Rong-Chuan. "Synthesis of polymers and oligomers containing fluorinated side groups for the construction of hydrophobic surfaces". Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2005. http://nbn-resolving.de/urn:nbn:de:swb:14-1120215670616-23184.
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Oligomers and polymers based on functionalized Rf-amides were successfully synthesized for the fabrication of hydrophobic surfaces with either linear or network structure. Firstly, new functionalized Rf-amides (RfCONH-, Rf is a perfluoroalkyl segment) were developed in most cases by a one step reaction and a simple work-up procedure. The reaction behaviors of synthesized Rf-amides in polyreactions were well understood. New fluorinated oligoester polyols, blocked IPDI's, and end-hydroxyl terminated oligo(urea urethane)s have been synthesized, the detail structures and properties are well understood. These materials could be suitable components of powder coatings. On the other hand, the end-hydroxyl terminated oligo(urea urethane)s could be used as reactive additives in high solid content and water-borne coatings. Hydrophobic smooth surfaces based on linear polymers, poly(urea urethane)s and alternating MI copolymers, containing fluorinated side groups were successfully constructed. The attachment of fluorinated side groups into polymers can dramatically alter the surfaces of corresponding polymers from more hydrophilic to hydrophobic due to the enrichment of fluorinated side groups on the top of the surface. The backbone configuration, the polarity of backbones, and the thermal treatment on surfaces can influence the surface properties of corresponding materials. Finally, hydrophobic surfaces of cross-linked polyurethanes as model top coatings were constructed under melt condition at high temperature (180 and 190 oC) using the combination of fluorinated oligouretdiones and non-fluorinated oligoester polyols. It was found that the hydrophobicity of resulting cured films is a matter of the competition between the formation of cross-linking network and the segregation of fluoromoieties on the top of the surface.
Części książek na temat "Lipophilic Groups"
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Suckling, Colin J., Roger D. Waigh, Abedawn I. Khalaf, John Parkinson i Iain S. Hunter. "Minor Groove Binders Substituted by Lipophilic Groups". W 19th International Congress on Heterocyclic Chemistry, 98. Elsevier, 2003. http://dx.doi.org/10.1016/b978-0-08-044304-1.50091-5.
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Silva Figueiredo, Barbara, Julyana Noval de Souza Ferreira, Vannyla Viktória Viana Vasconcelos, Priscila Ponate de Souza, Rafaela Vergna De Angeli i André Romero da Silva. "Synergic Influence of Parameters Involved in the Polymeric Nanoparticle Preparation on the Efficacy of Photodynamic Therapy". W Photodynamic Therapy - from Basic Science to Clinical Research [Working Title]. IntechOpen, 2020. http://dx.doi.org/10.5772/intechopen.94176.
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The challenge was always great for lipophilic photosensitizer use in the photodynamic therapy (PDT) for treatment of internal body diseases. Photosensitizer metabolism in liver, incompatibility of the molecules in the gastric acid, aggregation in the bloodstream, opsonization of molecules and phagocyting process hamper the application of the free lipophilic photosensitizer in disease treatment using PDT. This problem has been partially resolved using the drug delivery system to encapsulate the photosensitizer. Many studies have been reported using polymeric nanoparticles to encapsulate the lipophilic photosensitizer showing excellent results for PDT, but few nanoparticulate formulations are available at the pharmacies. The absence of deep knowledge about the influence of synergic effect of parameters used in the nanoparticle preparation on its properties, the photobleaching process of encapsulated photosensitizer and the molecule aggregation into the nanoparticle can decrease the photodynamic efficacy for the lipophilic photosensitizer. Our research group has studied the influence of many parameters on the nanoparticulate properties of several encapsulated phthalocyanines and porphyrin using factorial design, evaluating the free and encapsulated compound aggregation, efficacy to reduce the viability of cancer cells, the photooxidation of the biomolecules and the influence of photobleaching. This work shows the most important results to be consider in the optimization of the polymeric nanoparticle.
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"New Stratety for Peptide Synthesis Using Highly Lipophilic and Chromophoric Groups. Synthesis of Octapeptide Sequence [24 - 31]H-Lys-Asn-Ala-Tyr-Lys-Lys-Gly-Glu-0H of Human ß-Endorphin". W Proceedings of the Fifth USSR-FRG Symposium on Chemistry of Peptides and Proteins, Odessa, USSR, May 16–20, 1985, 19–28. De Gruyter, 1986. http://dx.doi.org/10.1515/9783110858846-004.
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Żołnierczyk, Anna K. "Nutritional Properties of Edible Insects". W Environmental, Health, and Business Opportunities in the New Meat Alternatives Market, 143–65. IGI Global, 2019. http://dx.doi.org/10.4018/978-1-5225-7350-0.ch008.
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Insects are the biggest animal group on earth. They constitute as much as 80% of the animal kingdom. Over 2000 species of insects are consumed in Central and South America, Africa, Asia, Australia, and New Zealand. Currently almost 1 billion people on this planet suffer from hunger, and we must strive to increase the efficiency of food production. One of the possible solutions is to use insects as a source of food. An important advantage of insect production is the high environmental safety compared to conventional livestock. Conventional animal husbandry is responsible for at least 18% of total greenhouse gas emissions and large consumption of drinking water. A much smaller amount of water is used to produce insect meat and insects require far less feed. Production of insect protein requires much less land and energy than the more widely consumed forms of animal protein. The nutritional usefulness of edible insects varies depending on the species, on the stage of development of the insect and the method of breeding and feeding. Insects have a high nutritional value. They are a rich source of protein which includes all eight essential amino acids (phenylalanine, isoleucine, leucine, lysine, methionine, threonine, tryptophan, and valine). Edible insects contain on average 10-30% of fat in dry matter and they are good source of edible oil which contains more than 50% of polyunsaturated fatty acids (PUFA) desirable for nutritional and health reasons. The average energy value of edible insects is about 400-500 kcal/100g of dry matter. Insects also contain a variety of water soluble or lipophilic vitamins and minerals. Their consumption can build a well-balanced diet. Insects can be regarded as safe, if properly managed and consumed, but international food regulations are needed.
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Żołnierczyk, Anna K. "Nutritional Properties of Edible Insects". W Research Anthology on Food Waste Reduction and Alternative Diets for Food and Nutrition Security, 1187–209. IGI Global, 2021. http://dx.doi.org/10.4018/978-1-7998-5354-1.ch061.
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Insects are the biggest animal group on earth. They constitute as much as 80% of the animal kingdom. Over 2000 species of insects are consumed in Central and South America, Africa, Asia, Australia, and New Zealand. Currently almost 1 billion people on this planet suffer from hunger, and we must strive to increase the efficiency of food production. One of the possible solutions is to use insects as a source of food. An important advantage of insect production is the high environmental safety compared to conventional livestock. Conventional animal husbandry is responsible for at least 18% of total greenhouse gas emissions and large consumption of drinking water. A much smaller amount of water is used to produce insect meat and insects require far less feed. Production of insect protein requires much less land and energy than the more widely consumed forms of animal protein. The nutritional usefulness of edible insects varies depending on the species, on the stage of development of the insect and the method of breeding and feeding. Insects have a high nutritional value. They are a rich source of protein which includes all eight essential amino acids (phenylalanine, isoleucine, leucine, lysine, methionine, threonine, tryptophan, and valine). Edible insects contain on average 10-30% of fat in dry matter and they are good source of edible oil which contains more than 50% of polyunsaturated fatty acids (PUFA) desirable for nutritional and health reasons. The average energy value of edible insects is about 400-500 kcal/100g of dry matter. Insects also contain a variety of water soluble or lipophilic vitamins and minerals. Their consumption can build a well-balanced diet. Insects can be regarded as safe, if properly managed and consumed, but international food regulations are needed.
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"Metabolism of Xenobiotics". W Environmental Toxicology, redaktor Sigmund F. Zakrzewski. Oxford University Press, 2002. http://dx.doi.org/10.1093/oso/9780195148114.003.0008.
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The action of most xenobiotics ends in either excretion or metabolic inactivation. Some compounds, on the other hand, require metabolic activation before they can exert any biological action. In most cases these biotransformations, activations as well as inactivations, are carried out by specialized enzyme systems. The essential role of these enzymes is to facilitate elimination of xenobiotics. Water-soluble compounds usually do not need to be metabolized, as they can be excreted in their original forms. Lipophilic compounds can be disposed of through biliary excretion, or they may undergo metabolism to become more polar and thus more water-soluble so that they can be disposed of through the kidneys. The metabolism of xenobiotics is usually carried out in two phases. Phase 1 involves oxidative reactions in most cases, whereas phase 2 involves conjugation (combination) with highly water-soluble moieties. Occasionally the products of biotransformation are unstable and decompose to release highly reactive compounds such as free radicals, strong electrophiles, or highly stressed three-member rings (epoxides, azaridines, episulfides, and diazomethane; Figure 3.1) that have a tendency toward nucleophilic ring opening. For order to be retained within the cells, the chemical reactions have to occur through enzymatic processes in which the substrate is activated while bound to the enzyme. Only after the desired reaction takes place is a stable product released. Freely roaming reactive compounds are not welcome in a living organism because they react randomly with macromolecules such as DNA, RNA, and proteins. Alteration of DNA leads to faulty replication and transcription. Alteration of RNA causes faulty messages that, in turn, lead to the synthesis of abnormal proteins and thus alter enzymatic and regulatory activity. Phase 1 processes are carried out by a series of similar enzymes (commonly designated as mixed-function monooxidases) or cytochrome P-450. The basic reactions catalyzed by cytochrome P-450 enzymes involve introduction of oxygen into a molecule. In most cases the oxygen is retained, but sometimes it is removed from the end product. The oxygen carrier is a prosthetic group containing porphyrin-bound iron. The overall reaction catalyzed by these enzymes is hydroxylation.
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Yılmaz, Bayram. "Endokrin Bozucuların Güncel Durumu, Ağır Metaller, Poliklorlu Bifeniller (PCBS), Parabenler, BHA, BHT". W Endokrin Bozucular ve Sağlık, 11–34. Türkiye Bilimler Akademisi Yayınları, 2022. http://dx.doi.org/10.53478/tuba.978-625-8352-04-7.ch02.
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Endocrine Disrupting Chemicals (EDCs) are a global problem for environmental and human health. They are defined as “an exogenous chemical, or mixture of chemicals, that can interfere with any aspect of hormone action”. It is estimated that there are about 1000 chemicals with endocrine-acting properties. EDCs comprise pesticides, fungicides, industrial chemicals, plasticizers, nonylphenols, metals, pharmaceutical agents and phytoestrogens. Persistent Organochlorine Pollutants (POPs) are substances that persist a long time in the environment and pose a threat for human health. Polychlorinated Biphenyls (PCBs) are a group of POPs that were widely used and banned in 1980s. PCBs may have neurotoxic, carcinogenic, immunotoxic, hepatatoxic, nephrotoxic and cytotoxic effects. Some PCBs resemble to estradiol 17-β and hence can mimic estrogenic effects. In contrast, coplanar PCBs mimic dioxin that they bind to aryl hydrocarbon receptor and causes anti-estrogenic effects. Heavy metals (mercury, lead, arsenic, cadmium and uranium) have been reported to have endocrine disruptive effects. However, their carcinogenic, neurotoxic and other adverse effects on human health are more important. Parabens are methyl, ethyl, propyl and ester forms of PHBA that are commonly used in food, pharmaceutical and personal care products. They have weak endocrine disruptive effects. Butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) are food additives as antioxidants. There are very few studies on the endocrine disruptor effects of BHA and BHT. Their use has been limited in USA, EU and Canada. Human exposure to EDCs mainly occurs by ingestion and to some extent by inhalation and dermal uptake. Most EDCs are lipophilic and bioaccumulate in the adipose tissue, thus they have a very long half-life in the body. It is difficult to assess the full impact of human exposure to EDCs because adverse effects develop latently and manifest at later ages, and in some people do not present. Timing of exposure is of importance. Developing fetus and neonates are the most vulnerable to endocrine disruption. EDCs may interfere with synthesis, action and metabolism of sex steroid hormones that in turn cause developmental and fertility problems, infertility and hormone-sensitive cancers in women and men. Some EDCs exert obesogenic effects that result in disturbance in energy homeostasis. Interference with hypothalamo-pituitary-thyroid and adrenal axes has also been reported. Potential EDCs, their effects and mechanisms of action, epidemiological studies to analyze their effects on human health, bio-detection and chemical identification methods, studying EDCs in humans and recommendations for endocrinologists, individuals and policy makers are reviewed.
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"Hudson River Fishes and their Environment". W Hudson River Fishes and their Environment, redaktorzy Isaac Wirgin i R. Christopher Chambers. American Fisheries Society, 2006. http://dx.doi.org/10.47886/9781888569827.ch19.
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<em>Abstract.</em>—Despite recent successes in eliminating or reducing many point sources of chemical contaminants, sediments in the Hudson River Estuary are still highly contaminated with lipophilic and highly persistent polychlorinated biphenyls (PCBs), polychlorinated dibenzo-<em>p</em>-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polycyclic aromatic hydrocarbons (PAHs). These have been shown to bioaccumulate to high levels in resource species and other key ecological components of the Hudson River food web. Resource managers and stewards must consider the possible toxic effects of these pollutants on the Hudson River biota, including its fish community; however, few studies have directly investigated these effects. A series of toxicological studies on Atlantic tomcod <em>Microgadus tomcod </em>from the Hudson River Estuary have demonstrated profound and broad-based changes in response to local contaminants. Levels of contaminants in the tissues of different life stages of tomcod from the Hudson River Estuary far exceed those in tomcod from other Atlantic Coast estuaries. More importantly, a combination of field and laboratory studies has demonstrated molecular to population level perturbations in tomcod from the Hudson River, all of which are consistent with chemical exposures and many of which appear to be mechanistically linked. These effects include induction of hepatic expression of cytochrome P4501A1 mRNA, high levels of hepatic DNA damage, somatic mutations at an oncogene locus critical to the initiation of chemical carcinogenesis, elevated prevalence of gross and histologically defined hepatic tumors, truncated age structure, and dramatic resistance at the molecular and organismal levels to halogenated aromatic hydrocarbons (HAHs). Resistance, a population level effect, was observed in the toxic responses of tomcod embryos and larvae to 2,3,7,8-tetrachlorodibenzo-<em>p</em>-dioxin (TCDD) and TCDD-like PCBs, but not PAHs. Because young of the year tomcod are a critical node in the Hudson River food chain, their evolved resistance to HAHs and high body burden of these and related contaminants has likely resulted in the trophic transfer of these contaminants to secondary and tertiary consumers of the Hudson River, including important resource species, and an elevated tissue burden of these contaminants in those consumers. In total, these studies are consistent with the hypothesis that exposure to Hudson River-borne contaminants has significantly altered its tomcod population and perhaps evoked broad change in the Hudson River fish community.
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"Hudson River Fishes and their Environment". W Hudson River Fishes and their Environment, redaktorzy Isaac Wirgin i R. Christopher Chambers. American Fisheries Society, 2006. http://dx.doi.org/10.47886/9781888569827.ch19.
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<em>Abstract.</em>—Despite recent successes in eliminating or reducing many point sources of chemical contaminants, sediments in the Hudson River Estuary are still highly contaminated with lipophilic and highly persistent polychlorinated biphenyls (PCBs), polychlorinated dibenzo-<em>p</em>-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polycyclic aromatic hydrocarbons (PAHs). These have been shown to bioaccumulate to high levels in resource species and other key ecological components of the Hudson River food web. Resource managers and stewards must consider the possible toxic effects of these pollutants on the Hudson River biota, including its fish community; however, few studies have directly investigated these effects. A series of toxicological studies on Atlantic tomcod <em>Microgadus tomcod </em>from the Hudson River Estuary have demonstrated profound and broad-based changes in response to local contaminants. Levels of contaminants in the tissues of different life stages of tomcod from the Hudson River Estuary far exceed those in tomcod from other Atlantic Coast estuaries. More importantly, a combination of field and laboratory studies has demonstrated molecular to population level perturbations in tomcod from the Hudson River, all of which are consistent with chemical exposures and many of which appear to be mechanistically linked. These effects include induction of hepatic expression of cytochrome P4501A1 mRNA, high levels of hepatic DNA damage, somatic mutations at an oncogene locus critical to the initiation of chemical carcinogenesis, elevated prevalence of gross and histologically defined hepatic tumors, truncated age structure, and dramatic resistance at the molecular and organismal levels to halogenated aromatic hydrocarbons (HAHs). Resistance, a population level effect, was observed in the toxic responses of tomcod embryos and larvae to 2,3,7,8-tetrachlorodibenzo-<em>p</em>-dioxin (TCDD) and TCDD-like PCBs, but not PAHs. Because young of the year tomcod are a critical node in the Hudson River food chain, their evolved resistance to HAHs and high body burden of these and related contaminants has likely resulted in the trophic transfer of these contaminants to secondary and tertiary consumers of the Hudson River, including important resource species, and an elevated tissue burden of these contaminants in those consumers. In total, these studies are consistent with the hypothesis that exposure to Hudson River-borne contaminants has significantly altered its tomcod population and perhaps evoked broad change in the Hudson River fish community.
Streszczenia konferencji na temat "Lipophilic Groups"
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Gerasimchuk, A. L., P. A. Bukhtiyarova, D. V. Antsiferov i D. A. Ivasenko. "Diversity and activity of cultivated lipophilic bacteria from fat-containing industrial wastes". W 2nd International Scientific Conference "Plants and Microbes: the Future of Biotechnology". PLAMIC2020 Organizing committee, 2020. http://dx.doi.org/10.28983/plamic2020.085.
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Pure cultures of lipophilic microorganisms of different phylogenetic groups were isolated from fat-containing industrial wastewaters. The strains of the genera Pseudomonas and Bacillus were the most active lipolytic microorganisms.
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Guo, Xin, i Ming Chang. "Effect of Oil Carbon Chain Length on the Physical Stability and Bioactivity of Nanoemulsion Delivery Systems Incorporating Lipophilic Ingredients". W 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/dyso6286.
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In the nanoemulsion-related research, enough studies have concentrated on the effect of oil types, especially oil carbon chain length, on the bioavailability of the phytochemicals. However, there is still a lack of systematical research on the effect of oil carbon chain length influencing whole delivery system, especially for bioactivity evaluation. Herein, the overall aim of this study was to test the effect of oil carbon chain length on the physical stability and bioactivity of the designed nanoemulision system. The emulsion had good physical stability during the incubation time, but no significant differences were detected in the physical stability among different treated groups. The best bioactivity (lipid-lowering effect, in vivo antioxidant activity) of tocopherol and sesamol was in the palm oil (long carbon chain length) group.Overall, this data is meaningful for underlying applications of designed system in lipophilic ingredients delivery.*Xin Guo, Biotechnology Division Student Award Winner*
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John, George, Jose James, Malick Samateh, Siddharth Marwaha i Vikas Nanda. "Sucralose Hydrogels: Peering into the Reactivity of Sucralose versus Sucrose Using Lipase Catalyzed Trans-Esterification". W 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/xkza4963.
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Sucralose differs from sucrose only by virtue of having three Cl groups instead of OH groups. Its intriguing features include being noncaloric, noncariogenic, 600 times sweeter than sucrose, stable at high temperatures/acidic pH's, and void of disagreeable aftertastes. These properties are attractive as food additive, one of which is as hydrogel obtainable via the technique of molecular gelation using a sucralose-derived low-molecular weight gelator (LMWG). The process of molecular gelation entails using specially designed lipid-like amphiphilic molecules capable of self-assembling in a liquid solvent to form a 3D-network. A rational molecular design would involve appending lipophilic alkyl chain to sucralose to afford sucralose-based amphiphiles. Our preliminary study has shown that sucralose, unlike sucrose, is unreactive under biocatalytic conditions using lipase enzyme, which is consistent with its reported lack of reactivity by hydrolytic enzymes in the body. Hence, the aim of this work was (i) to use computation and simulations to further understand sucralose's lack of enzymatic reactivity and (ii) to synthesize the sucralose-based amphiphiles using conventional chemical synthesis and systematically study their tendency towards hydrogelation. Three of the sucralose-based amphiphiles (SL-5, SL-6 and SL-7) proved to be successful hydrogelators. The gelators also showed the ability to gel selected beverages. The LMWGs gelled quantities of water and beverage up to 71 and 55 times their weight, respectively, and remain thermally stable up to 144 °C.
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Privat, Romain, Jean-Noe¨l Jaubert i Michel Molie`re. "Ethanol and Distillate Blends—A Thermodynamic Approach to Miscibility Issues: Part 2—The Influence of Water". W ASME 2011 Turbo Expo: Turbine Technical Conference and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/gt2011-45896.
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In recent years, the quest for sustainable primary energies has increased the potential interest of biogenic/fossil fuels mixes. As an example, ethanol is used as a gasoline extender to both partly substitute hydrocarbons and increase octane number while improving vehicle emissions. In a previous paper (GT2010-22126), it has been shown that ethanol and gasoil are able to blend and form homogeneous solutions only in limited proportion ranges, due to their markedly different physical and chemical properties. However the incorporation of small amounts of water in ethanol dramatically decreases this already narrow miscibility domain. Indeed, in function of the temperature, such ternary mixtures often give rise to liquid-liquid equilibria i.e. to two separated phases that are respectively lipophilic and hydrophilic. A key parameter is thus the Minimum Miscibility Temperature, i.e. the temperature above which ethanol, water and gasoil become completely miscible. On another hand, commercial gasoils do not constitute a single product but display worldwide a large range of compositions that influence the stability of these ternary blends. In this context, an investigation program intended to characterize and predict the stability of ternary ethanol + water + gasoil blends has been carried out by the LRGP laboratory (Laboratoire Re´actions et Ge´nie des Proce´de´s). The approach is based on a thermodynamical, theoretical calculation of the liquid-liquid phase diagrams formed by ethanol, water and a mixture of various hydrocarbons representative of the diesel oil pool using the group-contribution concept. The basic idea is that whereas there are thousands of chemical compounds, the number of functional groups that constitute these compounds is much smaller. The work relies on the experimentally verified theory that a physical property of a fluid can be expressed as the sum of contributions made by molecule’s functional groups, which allows correlating the properties of a very large number of substances in terms of a much smaller number of parameters that represent the contributions of individual groups. This work shows the huge influence exerted by the water content of ethanol on the shape of the liquid-liquid phase diagram and on the value of the Minimum Miscibility Temperature (MMT). As seen in our previous paper, the paraffinic, aromatic or naphthenic character of the fossil fraction, also considerably influences the value of the MMT. Calculations were performed with a water content varying between 1 and 10%. This study concludes that the MMT expressed in kelvins is generally multiplied by two when the water content rises from 1 to 10%.
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Akkerman, J. W. N., E. Kloprogge i P. L. B. Bruynzeel. "PLATELETS PLAY A ROLE IN THE IMMEDIATE ALLERGEN-INDUCED BRONCHOCONSTRICTIVE REACTION IN ASTHMATICS". W XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1642880.
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Platelet Activating Factor (PAF) is generally considered to play an important role in acute allergic reactions. A special example of such a reaction is allergic asthma and indirect evidence suggests that here too PAF may be involved. Direct proof for a role of PAF, however, is difficult to obtain since in blood PAF has an extremely short half-life due to its inactivation by an acetyl-hydrolase in plasma, its uptake and degradation by many cell types and its lipophilic properties making it easily stick to membranes. Despite these handicaps we report here that during an acute bronchoconstrictive reaction in asthmatics, PAF is liberated into the circulation and binds to platelets. Eight patients with allergic asthma were challenged by inhalation provocation. Four patients responded with an immediate bronchoconstrictive reaction, which was accompanied by a 40% decrease in freely accessible PAF-receptors on their platelets, collected 1 hour after bronchoconstriction (specific bindings of 3H-PAF decreased from 264 ± 44 to 164 ± 45 mol/platelet, p < 0.05). The patients who did qpt respond to allergen provocation failed to show a change in 3H-PAF binding. In both groups platelet counts and PAF-induced aggregation did not change significantly. In view of the high specificity of PAF-receptors on platelets (a 200-fold excess of histamine did not interfere) and the fact that in vitro3H-PAF-binding gradually becomes irreversible, we conclude that during an immediate bronchoconstrictive reaction circulating platelets make contact with PAF. Together with evidence that urtder similar conditions secreted products from platelets appear in the circulation, these data indicate that platelet activation by PAF forms an important step in the pathophysiology of allergic asthma.
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Elkady, Ashraf S. "DNA-Lipophilic Vitamins Supramolecular Complexes". W ASME 2008 2nd Multifunctional Nanocomposites and Nanomaterials International Conference. ASMEDC, 2008. http://dx.doi.org/10.1115/mn2008-47031.
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The self-assembly of supramolecular complexes between DNA and lipophilic vitamins, e.g. vitamin D group was examined, in the absence and presence of different cations, to the first time. A novel method for preparing DNA-lipophilic vitamins nanostructured complexes in the existence of divalent cations is introduced. The nanostructure of the supramolecular complexes ranged from beads-on-strings to compact globules and liquid crystalline forms depending on the vitamin nature, cations concentration and incubation time. A nucleation mechanism and flower-like aggregates are proposed as an initial state for complex formation. The biomedical applications of the functional nanostructured supramolecular complexes will be discussed in details.
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Tartis, Michaelann S., Jan Marik, Azadeh Kheirolomoom, Rachel E. Pollard, Hua Zhang, Jinyi Qi, Julie L. Sutcliffe i Katherine W. Ferrara. "Pharmacokinetics of Encapsulated Paclitaxel: Multi-Probe Analysis With PET". W ASME 2007 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2007. http://dx.doi.org/10.1115/sbc2007-176435.
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We have combined two imaging probes and used PET as a means to provide image-based validation for a novel targeted drug delivery system. The first probe was a direct labeling of the drug [18F]fluoropaclitaxel [1–3], which was inserted into various carrier vehicle formulations. The second probe, [18F]fluoro-1,2-dipalmitoyl-sn-glycerol, i.e. [18F]FDP involved radiolabeling the lipid vehicle. Paclitaxel, which is poorly soluble in aqueous media, also has limited solubility and stability in lipophilic environments such as liposomes. Stable association of paclitaxel with the lipid bilayer is affected by a variety of physicochemical factors such as temperature and liposome composition. Paclitaxel crystal formation has been documented, with two forms of solid state within aqueous media and organic solvents, although crystal conformation differs in each media [4,5]. We provide dynamic in vivo image sets providing biodistribution and time activity curves of free [18F]fluoropaclitaxel and liposomal [18F]fluoropaclitaxel as well as free [18F]FDP, liposomal [18F]FDP, and [18F]FDP in an ultrasound contrast agent. Serial studies were performed within a small group of rats, minimizing inter-animal variability. The two labeled molecules have different biodistributions: paclitaxel is rapidly taken up in the liver, intestines and kidneys, while the labeled lipid incorporated into liposomes stays in circulation with minimal uptake in organs other than spleen. Here, we have developed a quantitative method to follow paclitaxel and lipid vehicles to their destination in vivo in order to improve targeted paclitaxel delivery.