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Articles de revues sur le sujet "Biologically important compounds"
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Hart, John P., et Malcolm R. Smyth. « Electroanalysis of biologically important compounds ». Analytica Chimica Acta 244 (1991) : 295–96. http://dx.doi.org/10.1016/s0003-2670(00)82517-9.
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Covington, A. K. « Electroanalysis of biologically important compounds ». Electrochimica Acta 36, no 14 (janvier 1991) : 2196. http://dx.doi.org/10.1016/0013-4686(91)85234-x.
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Bartlett, P. N. « Electroanalysis of biologically important compounds ». Journal of Electroanalytical Chemistry and Interfacial Electrochemistry 310, no 1-2 (juillet 1991) : 454. http://dx.doi.org/10.1016/0022-0728(91)85283-u.
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Perrett, D. « Electroanalysis of biologically important compounds ». Chromatographia 38, no 11-12 (juin 1994) : 792. http://dx.doi.org/10.1007/bf02269638.
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Kissinger, P. T. « Electroanalysis of biologically important compounds ». Journal of Chromatography B : Biomedical Sciences and Applications 568, no 1 (juillet 1991) : 270. http://dx.doi.org/10.1016/0378-4347(91)80364-i.
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Mugesh, Govindasamy, Wolf-Walther du Mont et Helmut Sies. « Chemistry of Biologically Important Synthetic Organoselenium Compounds ». Chemical Reviews 101, no 7 (juillet 2001) : 2125–80. http://dx.doi.org/10.1021/cr000426w.
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Deshmukh, A. R., B. Bhawal, D. Krishnaswamy, Vidyesh Govande, Bidhan Shinkre et A. Jayanthi. « Azetidin-2-ones, Synthon for Biologically Important Compounds † ». Current Medicinal Chemistry 11, no 14 (1 juillet 2004) : 1889–920. http://dx.doi.org/10.2174/0929867043364874.
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Moriarty, Robert M., Yi-Yin Ku et Udai S. Gill. « Novel cyclopentadienyl ruthenium(II) complexes of biologically important compounds ». Journal of the Chemical Society, Chemical Communications, no 24 (1987) : 1837. http://dx.doi.org/10.1039/c39870001837.
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Honda, Y., R. Navarro-Gonzalez et C. Ponnamperuma. « Chemical yields of biologically important compounds from electric discharges ». International Journal of Radiation Applications and Instrumentation. Part C. Radiation Physics and Chemistry 33, no 3 (janvier 1989) : 287. http://dx.doi.org/10.1016/1359-0197(89)90202-6.
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Mugesh, Govindasamy, Wolf-Walther du Mont et Helmut Sies. « ChemInform Abstract : Chemistry of Biologically Important Synthetic Organoselenium Compounds ». ChemInform 32, no 39 (24 mai 2010) : no. http://dx.doi.org/10.1002/chin.200139275.
Texte intégralThèses sur le sujet "Biologically important compounds"
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Joussef, Antonio Carlos. « Free radical methods for synthesis of biologically important compounds ». reponame:Repositório Institucional da UFSC, 1990. https://repositorio.ufsc.br/handle/123456789/111799.
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Pandit, Bijan Kumar. « Solution thermodynamics of some biologically important compounds in various aqueous media ». Thesis, University of North Bengal, 2019. http://ir.nbu.ac.in/handle/123456789/3645.
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Miyahara, Tomoo. « Theoretical studies on the photochemistry of porphyrins and biologically important compounds ». 京都大学 (Kyoto University), 2003. http://hdl.handle.net/2433/148879.
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Rezai, M. Reza. « Synthesis of some biologically important compounds containing the bis(trifluoromethyl)ketal group as phosphate mimics ». Thesis, Brunel University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311540.
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Chincholkar, P. M. « Studies on the synthesis of azetidin-2-ones and their application in the synthesis of biologically important compounds ». Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 2009. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/2721.
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Camp, Claire L. « Combining elemental and molecular mass spectrometry to study 3 types of biologically important compounds : DNA, phosphopeptides and anticancer drugs ». Thesis, Loughborough University, 2014. https://dspace.lboro.ac.uk/2134/15129.
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Mass spectrometry was used to investigate three important biological molecules, deoxyribonucleic acid (DNA), phosphopeptides and oxaliplatin. The quantification of DNA is traditionally performed by UV spectroscopy; however the results can be affected greatly by the sample matrix. The method developed quantified phosphorus in digested calf thymus DNA and human DNA by high performance liquid chromatography (HPLC) coupled to inductively coupled plasma mass spectrometry (ICP-MS). The method presented showed excellent baseline separation between all 4 DNA mono-nucleotides and 5 UMP. Column recoveries ranging from 95% to 99% for phosphorus resulted in a mass balance of 95% ± 0.5% for standard nucleotides, determined by LC-ICP-MS, compared to total DNA determined by flow injection coupled to ICP-MS (FI-ICP-MS). Protein phosphorylation and de-phosphorylation is one of the most common signalling pathways within cells, it is involved in regulating cellular processes, mediating enzyme inhibition, protein-protein recognition and protein degradation. A novel approach to the selective detection of phosphopeptides based on the incorporation of a metal tag, gallium N,N-biscarboxymethyl lysine (Ga-LysNTA), in solution before separation and detection by liquid chromatography coupled to inductively coupled plasma mass spectrometry (LC-ICP-MS) was developed. Linear ion trap electrospray ionisation mass spectrometry (ESI-MS) was employed to study the interaction of the gallium tag with platelet derived growth factor beta receptor (β-PDGF), a small phosphopeptide. In addition molecular modelling was used to investigate the energetically favoured structures of both the Ga-LysNTA material and the β-PDGF-Ga-LysNTA complex. The complexation of the Pt-based anti-cancer drug oxaliplatin (OxPt) with biological ligands other than DNA is believed to be a major cellular sink for the drug reducing its therapeutic potential and acting as a potential cause of toxicity. The role of the naturally abundant cytoplasmic dipeptide ligand β-alanyl-L-histidine dipeptide (carnosine) in OxPt detoxification was investigated. Various mass spectrometry techniques employing electrospray ionization and chip nanospray were employed to study the interaction of oxaliplatin with carnosine as well as two of its derivatives β-alanyl-N-methylhistidine (anserine) and N-acetylcarnosine (NAC). Evidence of complexation between OxPt and each of the three ligands examined is presented. Most species observed were unambiguously assigned and compared to their theoretical isotopic patterns.
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Ghotekar, G. S. « Asymmetric synthesis of biologically important compounds and development of synthetically useful C-C and C-O bond forming reactions via transition metal free conditions ». Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 2019. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/5855.
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Liao, Jen-Hai, et 廖仁海. « Design and Synthesis of Nitrogen-Containing Compounds as the Hydrogen-Bond Receptors for Biologically Important Substrates ». Thesis, 2002. http://ndltd.ncl.edu.tw/handle/14070231422014712124.
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博士國立臺灣大學
化學研究所
90
This thesis presents the design and synthesis of nitrogen-containing compounds as the hydrogen-bond receptors for biologically important substrates, such as phosphates, carbohydrates and tripeptides. The structural cleft of phosphate receptor is established by incorporating four additional amido groups onto pyridine 2,6-biscarboxamide to provide a pseudo-tetrahedral cleft to hold phosphates in 1:1 complexation stoichiometry. The receptor with 1-pyrenylmethyl groups serves as a selective chemosensor for phosphates with unique recognition and sensing properties. The sensing mechanism appears to have phosphate ion encapsulated into the core of cleft via six hydrogen bonds, which disturbs the equilibrium between monomer and excimer fluorescence of pyrenyl moieties before and after complexation. This concept can be further applied in sensing pyrophosphate ion in water-containing solvents. BPN with daad hydrogen-bonding relay forms complexes with glycosides in 1:1 complexation. The binding trend among various saccharides is as follows: α-D-mannoside > β-D-glucoside > α-D-glucoside > β-D-galactoside > β-D-fructoside >β-L-fucoside≒β-D-ribofuranoside. The formation of multiple hydrogen-bonding complex adopts a rigid conformation to enhance fluorescence. More importantly, through themultiple HB effect the unusual push-pull daad relay conjugated through the ethynyl bridge further induces the p-electron delocalization of the intrinsic conjugated chromophore in BPN. These combinations lead to the operation of the multiple hydrogen-bonds induced charge transfer effect, resulting in drastic alternation on both UV-vis and fluorescence properties. The high affinity of BPN for β-D-glucoside, in combination with the high quantum yield and well-separated complex fluorescence, demonstrates its future suitability in developing glucose sensor. The amide-based receptor was designed and synthesized. The macrocyclic amides and ruthenium (II) bipyridyl moieties serve as recognition and sensing unit, respectively. A combinatorial approach is used to examine the recognition of this receptor with a library of tripeptides. The preliminary screening results indicate that the receptor binds the tripeptides having Gly and D-Ala amino acid residues.
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Wu, Yu-Ching, et 吳俞慶. « Selective Detection of Biologically Important Compounds at Metal Cyanide Complexes and Silicomolybdate-Doped-PLL-GA Film Modified Electrodes ». Thesis, 2008. http://ndltd.ncl.edu.tw/handle/25dw6a.
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碩士國立臺北科技大學
化學工程研究所
96
Part I：The present work describes oxidation of ascorbic acid (AA) at octacyanomolybdate-doped-glutaraldehyde-cross-linked poly-L-lysine ( PLL-GA-Mo(CN)84- ) film modified glassy carbon electrode in 0.1 M H2SO4. The modified electrode has been successfully prepared by means of electrostatically trapping the Mo(CN)84- mediator in the cationic film of glutaraldehyde-cross-linked poly-L-lysine. The dependence of peak current of modified electrode in pure supporting indicates that the charge transfer process was surface confined at low scan rates ( 5 to 200 mV s-1 ), and under mass transfer control at higher scan rates (200 to 1000 mV s-1). The advantage of cross-linked PLL-GA coating is that it extends the electrochemical activity of PLL-GA-Mo(CN)84- modified electrode over wide pH range compared to protonated poly(4-vinylpyridine) (PVP) based electrocatalytic assemblies. Cyclic voltammetry and rotating disc electrode (RDE) techniques are used to investigate the electrocatalytic oxidation of ascorbic acid and compared with its oxidation at bare and undoped PLL-GA film coated electrodes. The rate constant rate of catalytic reaction (k) obtained from RDE analysis was found to be 9.54 ×105 cm3mol-1s-1. The analytical determination of ascorbic acid has been carried out using RDE technique over the physiological interest of ascorbic acid concentrations with a sensitivity of 74.73 µA mM-1. Interestingly, although PLL-GA-Mo(CN)84- modified electrode facilitated the oxidation of ascorbic acid, the response of other electroactive biomolecules such as dopamine, uric acid, NADH, glucose were generally suppressed. This unique feature of PLL-GA-Mo(CN)84- modified electrode allowed for the development of a highly selective method for the determination of ascorbic acid in complex biological matrices. PartⅡ：The present work describes preparation and characterization of hexacyanoferrate-doped-glutaraldehyde-cross-linked poly-L-lysine (PLL-GA- Fe(CN)64-) film modified glassy carbon electrode and its application in detection of dopamine in the presence of ascorbic acid in pH 6.8 phosphate buffer solution (PBS). The modified electrode has been successfully prepared by electrostatically binding negatively charged Fe(CN)64- mediator into cross-linked poly-L-lysine cationic film. The dependence of peak current of modified electrode in pure supporting shows that the charge transfer process was surface confined at low scan rates, and under mass transfer control at higher scan rates. The PLL-GA-Fe(CN)64- film electrode retains its electrochemical activity over wide pH. Cyclic voltammetry and rotating disc electrode (RDE) techniques are used to investigate the electrocatalytic activity of modified electrode towards oxidation of dopamine and ascorbic acid. The PLL-GA-Fe(CN)64- film electrodes are successfully used for the individual estimation of both biomolecules in the concentration range of physiological interest. The sensitivity of modified electrode is more than 10 times higher for both dopamine and ascorbic acid when determined using RDE technique compared to cyclic voltammetry method. Finally, attempt has been made to use Nafion-coverd- PLL-GA-Fe(CN)64- film electrodes for the detection of dopamine in the presence of ascorbic acid by using voltammetric technique. Part Ⅲ：The present work describes reduction of hydrogen peroxide (H2O2) and bromate (BrO3-) at silicomolybdate-doped-glutaraldehyde-cross-linked poly-L-lysine (PLL-GA-SiMo) film modified glassy carbon electrode in 0.1M H2SO4. The modified electrode has been successfully prepared by means of electrostatically trapping the silicomolybdate mediator in the cationic film of glutaraldehyde-cross-linked poly-L-lysine. The dependence of peak current of modified electrode in pure supporting indicates that the charge transfer process was surface confined. Cyclic voltammetry was used to investigate the electrocatalytic reduction of H2O2 and BrO3-, and compared with their reduction at bare and undoped PLL-GA film coated electrodes. The analytical determination of bromate has been carried out in stirred solution with a sensitivity of 3.57 µA mM-1 over the linear concentration range between 5 ×105 and 1.2 × 10-4 M. Amperometric estimation of H2O2 in stirred solution at -50 mV (vs Ag/AgCl) shows a sensitivity of 0.57 µA mM-1. Interestingly, PLL-GA-SiMo modified electrode facilitated the reduction of H2O2, and not responded to potential interferrents such as dopamine, ascorbic acid and uric acid. This unique feature of PLL-GA-SiMo modified electrode allowed for the development of a highly selective method for the determination of H2O2 in the presence of interferents.
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Silva, Sandra. « The importance of phenolic compounds to the biological activity of virgin olive oil ». Doctoral thesis, 2017. http://hdl.handle.net/10451/30397.
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Tese de doutoramento, Farmácia (Bromatologia), Universidade de Lisboa, Faculdade de Farmácia, 2017Virgin olive oil (VOO) is the oil obtained from the fruit of the olive tree (Olea europaea L.) solely by mechanical or other physical means, under conditions that do not lead to alterations in the oil, which has not undergone any treatment other than washing, decantation, centrifugation or filtration. Oils obtained by this procedure are virgin olive oils and further quality assessment can lead to a classification as extra virgin olive oil (EVOO). VOO is the primary source of fat in the Mediterranean diet and has been associated with a lower incidence of chronic diseases, particularly cardiovascular diseases. Minor components of VOO include the phenolic compounds (e.g.: hydroxytyrosol (OHTyr), tyrosol, secoiridoids and flavonoids) and α-tocopherol. According to the European Food Safety Authority (EFSA) “the olive oil polyphenols contribute to the protection of blood lipids against oxidation reactions”, if the olive oil (OO) contains at least 5 mg of OHTyr and its derivatives per 20 g of oil. Urinary proteomic biomarkers enable an early, presymptomatic diagnosis of diseases, which makes them important and effective, but understudied, tools for primary prevention. In this work we studied the impact of a diet supplementation with OO, with different contents of phenolic compounds (18 mg or 286 mg caffeic acid equivalents per kg), on the urinary proteomic biomarkers of coronary artery disease (CAD), chronic kidney disease (CKD), and diabetes. Self reported healthy participants (n = 69) were randomly allocated to supplementation with a daily dose of 20 mL of OO, either low or high in phenolics, for 6 weeks. Urine and plasma samples were collected at baseline before OO consumption and after 3 and 6 weeks. The consumption of both olive oils improved significantly the proteomic CAD score at endpoint compared with baseline (p < 0.01). However, there was no difference between groups for other proteomic biomarkers or any secondary outcomes including plasma triacylglycerols, oxidized LDL, and LDL cholesterol. As there is a need to monitor intake of VOO, of following the dose in interventions, biomarkers in plasma and/or urine must be selected. In this work plasma and urine samples were collected before (0h) and until 6 h and 24 h, respectively, after ingestion of 50 mL of EVOO in a single dose, containing 322 mg/kg total phenolic content (caffeic acid equivalents), by healthy participants (n = 9). Although individual variability was observed among volunteers, we were able to select plasma and urinary secoiridoid metabolites as biomarkers to monitor EVOO intake. In order to explore novel properties of OHTyr, a chronic rheumatoid arthritis (RA) animal model, with rats, was used to evaluate the anti-inflammatory effects of OHTyr, using refined olive oil (ROO) as vehicle, at 0.5 and 5 mg/kg doses. The treatment at 5 mg/kg dose significantly decreased paw edema (p < 0.01), histological damage, cyclooxygenase-2 and inducible nitric oxide synthase expression (p < 0.001 versus positive control), and improved articular function in treated animals. Moreover for the same dose a significant decrease of TNF-α levels in serum was observed (p < 0.005 versus positive control and ROO). Acute inflammation, induced by carrageenan, was also evaluated for the same doses of OHTyr and using ROO as vehicle. Both doses significantly reduced paw edema (p < 0.001). Our results suggest that the supplementation of ROO with OHTyr may have an effect in RA with significant impact not only on chronic inflammation but also on acute inflammatory processes. Since the approval of the EFSA health claim, the analytical methodology that supports the dose calculation of OHTyr and its derivatives has been appraised as no standardized method for this aim exists so far. In our work a LC method coupled with high resolution mass spectrometry was implemented for determination of OHTyr and its derivatives to support the referred EFSA claim. Our results enhance the need of selection of target molecules to be monitored to assess the EFSA dose in order to proceed to an accurate quantification of these compounds in EVOO by using the adequate standards. As the bioactivity of VOO has been related with antioxidant capacity of phenolic composition, in this work we evaluated radical scavenging activity of EVOO phenolic extracts against peroxyl and hydroxyl radicals (ORAC and HORAC assays, respectively). The linear correlation obtained (r > 0.85) between the total phenolic content (Folin Ciocalteau assay) and the antioxidant capacity, measured as ORAC, shows that the Folin Ciocalteau assay is a suitable tool to preview EVOO oxidative stability concerning hydrophilic antioxidants with activity on peroxyl radical. No correlation was observed in which concerns HORAC antioxidant capacity and total phenolic content evaluated (Folin Ciocalteau assay). Within this work EVOO samples from different olive tree cultivars, different geographic origins, and different crops were characterized in which concerns phenolic compounds and α-tocopherol. To achieve this aim analytical methods were implemented and validated. Chemometric tools as Principal Component Analysis were applied for data analysis. EVOO samples from ‘Arbosana’ olive tree cultivar distinguished by its high levels of apigenin that were independent of its geographical origin, suggesting the use of apigenin, a typical VOO flavonoid, as varietal marker for this olive tree cultivar. The impact of EVOO storage, in the dark at room temperature, on phenolic composition and antioxidant capacity was also evaluated. After 12 months storage a mean decrease of total phenolic content of 21% was observed in EVOO samples that led to changes in antioxidant capacity of EVOO. Finally, as there is a need for the industry to have useful tools, without sample treatment, for rapid screening in VOO of total phenolic and α-tocopherol contents, infrared methods (FTIR-ATR) were implemented and validated within this work.
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Livres sur le sujet "Biologically important compounds"
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Hart, J. P. Electroanalysis of biologically important compounds. New York : Ellis Horwood, 1990.
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Electroanalysis of biologically important compounds. New York : E. Horwood, 1990.
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Sawyer, Donald T., et R. J. P. Williams. Oxygen Chemistry. Oxford University Press, 1992. http://dx.doi.org/10.1093/oso/9780195057980.001.0001.
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This book places oxygen on the center stage of chemistry in a manner that parallels the focus on carbon by 19th century chemists. One measure of the significance of oxygen chemistry is the greater diversity of oxygen-containing molecules than of carbon-containing molecules. One of the most important compounds is water, containing the properties of being a unique medium for biological chemistry and life, the source of all the dioxygen in the atmosphere, and the moderator of the earth's climate. Sawyer first introduces the biological origins of dioxygen and role of dioxygen in aerobic biology and oxidative metabolism, and in separate chapters discusses the oxidation-reduction thermodynamics of oxygen species, and the nature of the bonding for oxygen in its compounds. Additional chapters focus on the reactivities of specific oxygen compounds. The book will be of interest to chemists and biochemists, as well as graduate students, life scientists, and medical researchers.
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Hanahan, Donald J. A Guide to Phospholipid Chemistry. Oxford University Press, 1997. http://dx.doi.org/10.1093/oso/9780195079814.001.0001.
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This book provides a concise introduction to phospholipid chemistry and is intended for a broad audience of biologists, biochemists, and graduate students. Developed as part of a graduate course on lipids, this book also serves as a reference for laboratory investigators on signal transduction and biological membranes. The first part of the text is devoted to an orientation to the chemical nature of lipids in general, how they are thought to be associated in the cell, and the methodology by which the cellular lipids (including the phospholipids) can be recovered from cells and subjected to an initial identification. Subsequent chapters characterize the choline-containing phospholipids, including the sphingolipids, the non-choline containing phospholipids, and finally, the so-called minor phospholipids. The latter compounds, which act as agonists or lipid chemical mediators on cells, form a vanguard of a new category of biologically active substances and have set the study of cellular phospholipids on a new and exiting course. Most importantly, this book provides a basis for further inquiry on these complicated molecules, showing that although the compounds are unique, with care and understanding, they can be studied with ease
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Pearce, Tim C. Chemosensation. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780199674923.003.0017.
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Olfaction in animals still surpasses any technological solution to chemical sensing yet conceived. While certain classes of molecular detection technologies may be capable of high sensitivity to a restricted number of compounds, unique to the biological system is its astonishing dynamic range (over 10 orders of magnitude), combining both extreme levels of sensitivity to certain key compounds of behavioural importance and varying levels of discrimination between an almost infinite variety of ligands, presented both individually and in complex combinations. For over 30 years the olfactory system of insects and mammals has provided biological sensing factors, rich inspiration, and processing principles for use in developing chemical sensing technologies. Here we focus on three such technological translations: recent rapid progress in measuring directly from olfactory binding/receptor proteins and chemosensory neurons as a biohybrid solution to chemical sensing; olfactory system based processing principles and architectures that have been applied to existing chemosensor technologies to achieve real-world sensing performance gains; and full-blown neuromorphic implementations of the olfactory pathways of animals.
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Novikov, Roman, Denis Borisov, Leonid Menchikov et Yuriy Tomilov. Donor-acceptor cyclopropanes. Cycloaddition and annulation reactions. LCC MAKS Press, 2022. http://dx.doi.org/10.29003/m2659.978-5-317-06797-7.
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This is the second book in the Donor-Acceptor Cyclopropanes series. It summarizes and analyzes for the first time the main intermediates formed from D-A cyclopropanes, and also systematizes the main ways of their further transformations. The main attention is paid to the cycloaddition and annulation reactions of D-A cyclopropanes with various substrates under the action of Lewis acids, which are of the greatest practical importance in organic synthesis. The monograph is addressed to a wide range of specialists in the field of small cycle chemistry and organic synthesis, including the synthesis of natural compounds and biologically active substances
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Glorieux, Griet, Nathalie Neirynck, Anneleen Pletinck, Eva Schepers et Raymond Vanholder. Overview of uraemic toxins. Sous la direction de Jonathan Himmelfarb. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780199592548.003.0254_update_001.
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The uraemic syndrome is a complex mixture of organ dysfunctions attributed to the retention of a multitude of compounds that under normal conditions are excreted by healthy kidneys. Although important progress has been made in the identification and characterization of uraemic retention solutes and in the revealing of their pathophysiological effects, this knowledge remains far from complete. Data are discussed on general characteristics of specific uraemic retention solutes, on in vitro and in vivo biological effects and on available observational and interventional studies with respect to their removal and related patient outcome are discussed.
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Parkhomenko, Yu M., et G. V. Donchenko. Vitamins in Human Health. PH “Akademperiodyka”, 2006. http://dx.doi.org/10.15407/akademperiodyka.063.182.
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The book describes the history of the discovery of vitamins, presents modern ideas about the properties of vitamins and their importance for humans as essential nutritional factors. General information is provided about the modern classification of vitamins, physicochemical and biological properties of water- and fat-soluble vitamins and vitamin-like compounds, their role in metabolism and, in general, in human health. The causes of hypovitaminosis are analyzed, advice is given on their prevention and storage of vitamins in food. The book is intended for specialists in the field of biology, medicine, as well as for a wide range of readers, including teachers, students and other people interested in health issues.
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Vairappan, Charles S. Ecological Chemicals as Ecosystem Function Mediaters and Potential Lead Pharmaceuticals. UMS Press, 2021. http://dx.doi.org/10.51200/ecologicalchemicalsumspress2021-978-967-2962-94-6.
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Relationship between functioning ecosystem services and human wellbeing has been established as a bridge connecting nature and society. It has also become central pillar of sustainability science and dictates the paradigms of sustainable development. But, conceptual frameworks that systematically integrates the important roles played by natural ecological chemicals by establishing empirical links between the nature and ecology not only varies, but lacks clear support. The value of ecological chemicals as ecosystem derived natural products warrants explicit acknowledgement, only then trade-offs between services and prioritization of policy can be realised. In the last 20 years, important roles played by the ecological chemicals in Bornean terrestrial and marine ecosystems were investigated and reported. Terrestrial plants produce Volatile Organic Chemicals (VOCs) and structurally interesting secondary metabolites that facilitate their ecological processes that are aimed to establish communication such as defence, attraction, deterrent and territorial marking. Some of the most commonly utilized herbs and plants of traditional medicine importance showed very interesting chemical constituents, that justify their traditional utilization for human wellbeing. The role of VOCs that originated from animal diet and emitted through decomposition of faeces, was traced back to their important role as attractants of insects, particularly dung beetles that facilitates the remineralization of faeces and returns C and N to soil as to replenish global C and N-sink. Marine flora and fauna are perhaps the most vivid producers of structurally interesting secondary metabolites with more than one ecological functions. Halogenated secondary metabolites produced by red algae Laurencia are unique in their structural design and exhibited multiple biological potentials. Similarly, soft corals in the Sulu-Sulawesi Coral Triangle produced a huge diversity of terpenoids and functions as feeding deterrents of these soft bodied invertebrates. Ecological chemicals obtained from the Bornean biodiversity also exhibited a wide array of medically important biological activities such as anti-microbial, anti-inflammation, anti-anticancer and serves an important array of lead pharmaceuticals. Some of these compounds are very potent and have been patented as lead-pharmaceutical candidates from Bornean natural products. Hence, ecological chemicals are important natural products that regulate ecological processes that ensures ecological balance in tropical ecosystems. Humans who are the custodians of natural ecosystem, stand to benefit directly and indirectly when we practice sustainable utilization and regulation of our natural resources.
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Dudek, Piotr. Vision. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780199674923.003.0014.
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Vision is a sensory modality of primary importance to many animal species. The efficient implementation of visual perception is also one of the main challenges in the design of intelligent robotic systems. This chapter reviews the principles of operation and key features of the early stages of biological vision systems. Following the observation that visual information processing starts in the eye, it reviews several approaches to constructing biomimetic artificial vision systems. It presents devices inspired by the morphology of the insects’ compound eyes, and devices tightly integrating image sensing and processing circuitry. These include silicon integrated circuits mimicking the operation of vertebrate retinas, and bio-inspired systems oriented towards machine vision applications, such as dynamic vision sensors and vision chips with pixel-parallel cellular processor arrays. It elucidates the advantages of the near-sensor processing of the visual information, and potential for future developments of neuromorphic vision sensors.
Chapitres de livres sur le sujet "Biologically important compounds"
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Iqbal, Nadia, Sidra Nisar Ahmed, Urooj Subhan, Nageen Arif, Humaira Saleem et Farah Deeba. « Application of Biotechnology to Produce Plant-Derived Biologically Important Compounds ». Dans Bioprospecting of Tropical Medicinal Plants, 1047–59. Cham : Springer Nature Switzerland, 2023. http://dx.doi.org/10.1007/978-3-031-28780-0_43.
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Lundt, Inge. « Iminosugars, Isoiminosugars, and Carbasugars from Activated Carbohydrate Lactones : Efficient Synthesis of Biologically Important Compounds ». Dans ACS Symposium Series, 117–40. Washington, DC : American Chemical Society, 2002. http://dx.doi.org/10.1021/bk-2003-0841.ch007.
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Corn, M., S. Belviso, F. Partensky, N. Simon et U. Christaki. « Origin and Importance of Picoplanktonic DMSP ». Dans Biological and Environmental Chemistry of DMSP and Related Sulfonium Compounds, 191–201. Boston, MA : Springer US, 1996. http://dx.doi.org/10.1007/978-1-4613-0377-0_17.
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Inch, Thomas D. « The Biological Importance of Organophosphorus Compounds Containing a Carbon-Phosphorus Bond ». Dans Ciba Foundation Symposium 57 - Phosphorus in the Enviroment : Its Chemistry and Biochemistry, 135–53. Chichester, UK : John Wiley & Sons, Ltd., 2008. http://dx.doi.org/10.1002/9780470720387.ch8.
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Theng, Benny K. G. « Interactions of Clay Minerals with Organic Compounds of Biological and Environmental Importance ». Dans The Chemistry of Clay-Organic Reactions, 121–80. 2e éd. Boca Raton : CRC Press, 2024. http://dx.doi.org/10.1201/9781003080244-3.
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Jain, Neha, Mukesh Kumar Sharma et Pallavi Kaushik. « Therapeutically Important Bioactive Compounds Derived from Fungal Origin ». Dans Therapeutic Implications of Natural Bioactive Compounds, 223–35. BENTHAM SCIENCE PUBLISHERS, 2022. http://dx.doi.org/10.2174/9789815080025122030014.
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The rising of chronic ailments impinged on humans worldwide has paved the urgent need for newer therapeutic vital compounds that are biologically active and have the capacity to endeavour without exerting any adverse or cytotoxic effects. This necessitates extensive research to investigate unexplored natural sources for such promising sources. A diverse array of fungi species has garnered considerable attention over the past century due to the assortment of their opportunities to generate novel active ingredients with multifunction mechanisms towards recuperative applications. Some of the fungal bioactive compounds possess exclusive therapeutic potential and pharmaceutical importance. These efficacious bioactive compounds including Paclitaxel, Podophyllotoxin, Enniatins, Camptothecin, Ascophytatin with their properties like anti-bacterial, antiviral, anti-parasitic, anti-diabetic, anti-cancerous, immunomodulatory are discussed in this chapter.
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Coronado-Cáceres, Luis Jorge, Sergio de Jesus Calva-Estrada et Eugenia Lugo-Cervantes. « Biologically Active Peptides from Cocoa Bean (Theobroma cacao L.) ». Dans Frontiers in Bioactive Compounds, 191–204. BENTHAM SCIENCE PUBLISHERS, 2023. http://dx.doi.org/10.2174/9789815123340123040015.
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Recently, proteins and peptides have become important ingredients in functional foods due to the emergence of knowledge about their properties and biological activities. Many biologically active peptides (BAPs) have been studied from different animal and vegetal origins, principally legumes, such as soybeans and beans. BAPs have been shown to have anticancer, antitumoral, antioxidant and antimutagenic activities. Cacao, an ancient crop that originated in the Mesoamerican region, contains several bioactive compounds, e.g., polyphenols, alkaloids, flavanols, procyanidins and peptides. Cocoa beans contain 50% lipids and 14% protein, with albumins and globulins prevailing. The principal amino acids from cocoa protein are lysine, arginine, serine, proline, alanine, leucine, valine and methionine, and they allow the elucidation of the peptide’s bioactivity. Cocoa BAPs show antitumoral, antioxidant, antihypertensive and antidiabetic activities and obesity prevention. This work demonstrates the potential of all its BAPs.
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Okuyama, Tadashi, et Howard Maskill. « Electrophilic Aromatic Substitution ». Dans Organic Chemistry. Oxford University Press, 2013. http://dx.doi.org/10.1093/hesc/9780199693276.003.00016.
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This chapter focuses on aromaticity - the parent member of a large class of so-called aromatic compounds. It shows that benzene is a conjugated unsaturated compound which has special stability attributed to aromaticity. However, an organic compound does not have to be either aromatic, or not, as a whole: molecules of many compounds, including natural products and biologically important compounds, contain aromatic and non-aromatic residues linked together. The chapter then displays the distinguishing feature of an aromatic compound: its cyclic system of delocalized ? electrons. It looks at electrophilic aromatic substitution and the main reactions of benzene: halogenation, nitration, sulfonation, and Friedel-Crafts alkylation and acylation. Next, the chapter analyzes the regioselectivity of electrophilic substitution directed by substituents and the reactivity of phenol and aniline. It also looks at the preparation of substituted benzenes.
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Naushad, Edayadulla, et Shankar Thangaraj. « Naturally Isolated Pyridine Compounds Having Pharmaceutical Applications ». Dans Chemistry with Pyridine Derivatives [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.106663.
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Heterocyclic moieties form important constituents of biologically active natural products and synthetic compounds of medicinal interest. Nitrogen heterocycles constitute important pharmacophores in drug design, especially pyridine derivatives, which are among the most frequently cited heterocyclic compounds. The isolated as well as synthesized pyridine compounds exhibited various pharmacological properties due to their diverse physiochemical properties like water solubility, weak basicity, chemical stability, hydrogen bond-forming ability, protein-binding capacity, cell permeability, and size of the molecules attracted the attention of medicinal chemists for the past few years. Their interesting molecular architecture seeks attention to isolate derivatives of medicinal interest from natural source. In this chapter, we plan to describe the isolated natural products having pyridine moiety and their pharmacological importance.
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Castro-Jácome, Tania P., et Erik G. Tovar-Pérez. « Biologically Active Peptides from Sorghum [Sorghum bicolor (L.) Moench] Grain ». Dans Frontiers in Bioactive Compounds, 115–27. BENTHAM SCIENCE PUBLISHERS, 2023. http://dx.doi.org/10.2174/9789815123340123040010.
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Sorghum (Sorghum bicolor L. Moench) is an important staple food crop grown worldwide, easy to grow and drought tolerant. In recent years, sorghum grain has been increasingly regarded as a promising feedstock for the production of bioactive compounds. In particular, its main protein (kafirins fraction) has been used for the generation of biologically active peptides due to its high hydrophobic amino acid content and its hypoallergenicity. Several studies have shown that sorghum-derived peptides have antioxidant, anticancer, antimicrobial and anti-inflammatory activities, among others. These beneficial health effects could be attributed to the fact that in general, peptides derived from kafirins present glutamic acid and non-polar amino acids: proline, leucine and alanine. It has been reported that the presence of these hydrophobic amino acids in peptides facilitates their interaction with free radicals by neutralizing them, in addition to their low molecular weight and the position of the amino acids in the peptide sequence. Therefore, sorghum is a cereal with high potential for the production of biologically active peptides with benefits for human health.
Actes de conférences sur le sujet "Biologically important compounds"
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Urazbaeva, Zemfira G., Alfiya R. Bayguzina et Ilfir R. Ramazanov. « Fe-Catalyzed Synthesis of 2-Benzoxazolone—An Important Fragment of Biologically Active Compounds ». Dans International Electronic Conference on Synthetic Organic Chemistry. Basel Switzerland : MDPI, 2022. http://dx.doi.org/10.3390/ecsoc-26-13564.
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J. AJEENA, Saba, Zainab A. JABARAH et Suhayla khalied MOHAMMED. « EVALUATION THE ANTIOXIDANT ACTIVITY OF ALEO VERA LEAVES EXTRACTS ». Dans VII. INTERNATIONAL SCIENTIFIC CONGRESSOF PURE,APPLIEDANDTECHNOLOGICAL SCIENCES. Rimar Academy, 2023. http://dx.doi.org/10.47832/minarcongress7-8.
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Certain chemical compounds, such as biologically active molecules, can be produced and found in high concentrations in plants. Aloe vera plant consists mainly of more than 90% water and many chemical compounds, such as polysaccharides, due to its ability to adapt to desert conditions and environments. More than 200 nutritional substances were found to be exist in aloe vera, including vitamins, enzymes, minerals, polysaccharides, lignin, antioxidants and amino acids. flavonoids and phenols, among the important compounds, play an important and vital role as antioxidants by their function as free radicals’ scavengers. The current research is aiming to investigate the value of total polyphenols , flavonoids and antioxidant activities of magnetized water, non-magnetized water and alcoholic extracts of fresh Aloe Vera leaves .The study showed that the extracts of ethanol and magnetized water are much better than non-magnetized water.
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Poteshkina, K. I., et A. M. Stenkova. « DEVELOPMENT OF A TEST SYSTEM FOR SCREENING BACTERIA PRODUCING BIOLOGICALLY ACTIVE NONRIBOSOMAL PEPTIDES AND POLYKETIDES ». Dans X Международная конференция молодых ученых : биоинформатиков, биотехнологов, биофизиков, вирусологов и молекулярных биологов — 2023. Novosibirsk State University, 2023. http://dx.doi.org/10.25205/978-5-4437-1526-1-360.
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An important direction in science and medicine is the study of biologically active compounds produced by marine microorganisms, due to which there is a search for new promising drugs. This study is aimed at screening a collection of marine microorganisms obtained from invertebrates from the Vostok Bay of Primorsky Krai for the presence of biochemical gene clusters of nonribosomal peptide synthetases (NRPS) and polyketide synthases (PKS).
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Velciov, Briana Bianca, Maria Rada, Lalescu Virgil -Dacian, Daniela Stoin et Aliodor Marius Suciu. « PRELIMINARY RESEARCH REGARDING THE IMPACT OF MOISTURE CONTENT ON NUTRITIONAL PARAMETERS OF NETTLE POWDER ». Dans 23rd SGEM International Multidisciplinary Scientific GeoConference 2023. STEF92 Technology, 2023. http://dx.doi.org/10.5593/sgem2023v/6.2/s25.41.
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Nettle leaf powder is an excellent source of nutritional compounds (proteins, minerals, fibers, carbohydrates) and biologically active compounds: terpenoids, carotenoids, fatty acids, various polyphenolic compounds, essential amino acids, chlorophyll, vitamins, etc., essential for the health of the human body. Therefore, nettle powder could be used as a nutritional supplement. The nutritional quality of the nettle powder can be influenced by the drying technique of the nettle leaves, respectively by the water content of the final product. This study aims to evaluate the nutritional content of nettle powder obtained by drying nettle leaves through three drying processes. Basically, the variation of moisture, ash, protein, fiber and carbohydrate content of nettle leaf powder obtained by drying was observed in case of fresh leaves of wild nettle (Urtica dioica L.) from the spontaneous flora, using three drying methods: shade drying (SHD), sun drying (SD) and oven drying (OD). The obtained results show that the nettle leaf powder obtained under the conditions of this experiment contains important amounts of nutritional compounds. This research provides evidence that nettle leaf powder contains greatly increased amounts of nutrients compared to fresh leaves.
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Chiselita, Oleg, Natalia Chiselitsa, Elena Tofan, Alina Beshliu, Nadejda Efremova, Marina Danilis et Ana Rotaru. « Antocyanic extracts from yeast winewaste ». Dans 5th International Scientific Conference on Microbial Biotechnology. Institute of Microbiology and Biotechnology, Republic of Moldova, 2022. http://dx.doi.org/10.52757/imb22.15.
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Phenolic compounds, especially phenolic acids, tannins and anthocyanins are among the important biologically active components of wines. Of all the phenolic compounds, anthocyanins are of a particular interest because they have many beneficial effects on human and animal health. In vitro and in vivo studies have revealed the biological potential of these compounds and demonstrated their ability to reduce oxidative stress, to act as antimicrobial substances and to counteract the appearance and progression of many nontransmissible diseases, such as neurodegenerative, cardiovascular, metabolic ones and cancer. In combination with vitamin A and other carotenoids they protect visual function. Anthocyanins and their derivatives have no toxic effect on living organisms, even after ingestion in very high doses. Since the biologically active substances, including anthocyanins, found out in the fermentation medium, are largely absorbed on the surface of the yeast cells, yeast biomass remaining from wine production, can serve as an important source of these substances. The purposes of this research were to obtain anthocyanin extracts from the yeast biomass remaining from the production of the autochthonous wines, to characterize them biochemically, and to assess their antioxidant potential. The research was focused on the sediment yeast biomass from the production of white dry wine Rkatsiteli, red dry wines Merlot and Cabernet, offered by the «Cricova» winery. The extracts were obtained by different methods of destruction of the yeast cell wall, which included the use of the acetic acid and the sodium phosphate buffer solutions, homogenization, different temperatures and biomass-solution ratios. The extracts were characterized by their dry weight, by the content of the anthocyanins, proteins, and carbohydrates, as well as by the activity of the antioxidant enzymes catalase and superoxide dismutase. Depending on the yeast biomass type and the cell wall destruction method the obtained extracts had the dry weight of 2.2 - 13.3 mg/ml, and contained 3.9±0.3 - 20.7±0.4 mg/g of cyanidin anthocyanins, 3.2±0.2 - 9.7±0.4% (d.w.) of proteins, 2.2±0.02 - 31.4±0.3% (d.w.) of carbohydrates, and possessed the antioxidant type catalase activity of 315±2.6 - 524±1.5 mmol/min/mg protein and the superoxide dismutase of 173±5.2 - 457±0.6 U/mg protein. The valuable biochemical composition and high activity of the antioxidant enzymes such as catalase type and superoxide dismutase of the extracts revealed the perspectivity of using the yeast biomass from wine production as a source of anthocyanin preparations for various fields. The results of the research permitted to elaborate a procedure of obtaining the anthocyanin preparations from yeast biomass after red wine fermentation, which is currently being patented.
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Dimić, Dušan, Dejan Milenković, Edina Avdović, Goran Kaluđerović et Jasmina Dimitrić Marković. « MOLECULAR DOCKING AND MOLECULAR DYNAMICS STUDIES OF THE INTERACTION BETWEEN COUMARIN-NEUROTRANSMITTER DERIVATIVES AND CARBONIC ANHYDRASE IX ». Dans 1st INTERNATIONAL Conference on Chemo and BioInformatics. Institute for Information Technologies, University of Kragujevac,, 2021. http://dx.doi.org/10.46793/iccbi21.056d.
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Novel biologically active compounds can be obtained by the structural modification of coumarins. In this contribution, five new derivatives of 4-hydroxycoumarin with tyramine, octopamine, norepinephrine, 3-methoxytyramine, and dopamine were obtained. Their structures were optimized based on the previously obtained crystal structure of the 4-hydroxycoumarin-dopamine derivative. The special emphasis was put on the effect of various substituents on the structure of obtained compounds and intramolecular interactions governing the stability. To investigate their possible antitumor activity, molecular docking and molecular dynamics simulations were performed with Carbonic anhydrase, a prognostic factor in several cancers, and compared to the native ligand, 5-acetamido-1,3,4-thiadiazole- 2-sulfonamide. The results have shown that all of the coumarin-neurotransmitter derivatives bind to the active pocket of protein with the binding energies higher than for the native ligand. The main contributions to the binding energies were discussed. The Root Mean Square Deviation (RMSD), Root Mean Square Fluctuation (RMSF), and Radius of gyration (Rg), as results of MD simulations, were used to predict the activity of compounds towards chosen protein. The highest MD binding energies were obtained for the derivatives with dopamine and 3-methoxytyramine, with the van der Waals interaction and hydrogen bonds being the most important contributors.
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Hasyim, Saiyidah Nafisah, Norrizah Jaafar Sidik, Tay Chia Chay, Nur Nadirah Rodzali, Siti Nur Azmu’i Abdullah et Noor Amira Muhammad. « Phytochemical Compounds and Antioxidants Analysis of <i>Clinacanthus nutans </i>Leaf and Stem Extracts ». Dans International Conference on Nanoscience and Nanotechnology 2022. Switzerland : Trans Tech Publications Ltd, 2023. http://dx.doi.org/10.4028/p-9qsg4u.
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Clinacanthus nutans consists with multiple medicinal properties. The plant is also known to be a source of biologically active compounds, particularly those with an antioxidant capacity. The phytochemical studies of C. nutans plant extract was mostly reported from its leaf part. Thus, the objectives of this study are to assess the phytochemical constituents and antioxidant activity of C. nutans leaf and stem. Methanol was used as solvent for the green extraction. Next, phytochemical screening, Fourier transform infrared (FTIR) analysis, total phenolic (TPC) and flavonoids contents (TFC), quercetin flavonoid compound analysis and in vitro antioxidant activity were performed on C. nutans leaf and stem. In comparison to stem extract, the leaf extract showed a more favorable appearance of metabolites. In FTIR analysis, both sample extracts revealed the presence of hydroxyl and carbonyl functional groups, which are important in antioxidant action. The TPC (228.06 mg GAE/g DW) and TFC (29.76 mg QE/g DW) values were higher in the leaf extract than the stem extract. Quercetin quantification in HPLC analysis revealed that the leaf extract (21.33 g/g) contained more quercetin than the stem extract (18.88 g/g). Between the extracts, leaf providing more antioxidant values of DPPH (15.50%) and FRAP (15.68 gFeSO4/g) than stem. The greatest association was identified between TFC and FRAP reducing activity (r = 0.977, p<0.05) indicating that the flavonoid present in the extract contributed to C. nutans' antioxidant capacity.
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Babarykin, Dmitry, Gaļina Smirnova, Svetlana Vasiļjeva, Anna Fedotova, Andrey Fedotov et Natālija Basova. « Evaluation of the biological activity of sugar-free fractionated red beetroot juice ». Dans 80th International Scientific Conference of the University of Latvia. University of Latvia, 2023. http://dx.doi.org/10.22364/iarb.2022.05.
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In the case of type II diabetes, the most important preventive and therapeutic effect gives a diet with a minimal amount of easily digestible carbohydrates. Vegetable juices are posi-tioned as healthy food, because of the high content of phenolic and other biologically active compounds. However, due to the high glycemic index, juices are contraindicated in obesity, and diabetes, while juices with a reduced glycemic index, are not available on the market. We have developed a technology for the fractionation of red beetroot juice based on molecular mass using ultrafiltration. The resulting fraction stimulates the absorption of iron, increases blood hemoglobin level, and enhances capillary blood flow more effectively than native juice does. Both effects are important for patients with diabetes because the impaired blood supply to tissues and organs is an important pathogenetic factor in the development of diabetic renal failure, blindness, and gangrene. The sugar content in fractionated beetroot juice is 5–7%, which makes its use in diabetes problematic. The purpose of the study was to develop a technology for removing sugar from fractionated red beetroot juice and assessing the safety of its functional properties. The fractionated native red beetroot juice and fractionated fermented juice were studied. Fermentation was carried out using pre-activated yeast Saccharomyces cerevisiae. It was found that after 5-day fermentation, the sugar content in the fermented fractionated juice fell to 0.5–0.7%, while maintaining functional activity.
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Šarko, Julita, et Aušra Mažeikienė. « Investigation of Sorbents for Phosphorus Removal ». Dans 11th International Conference “Environmental Engineering”. VGTU Technika, 2020. http://dx.doi.org/10.3846/enviro.2020.620.
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Nowadays, the problem of water pollution with phosphorus compounds is especially important. Wastewater treatment plants do not always meet the strict requirements for the residual total phosphorus concentration – 1 mg/l in the treated wastewater. Usually individual wastewater treatment plants have a poorer removal of phosphorus from the wastewater because they are more sensitive to fluctuations in wastewater flow and environmental conditions. Research results in the scientific literature shows that only 30–50% of the phosphorus is removed from the wastewater by conventional methods. Additional wastewater treatment is recommended for higher phosphorus removal efficiency achievement. One of the ways to remove phosphorus from wastewater is filtration through sorbents filter media. The efficiency of three sorbents – Filtralite P, foam-glass and crushed shells to remove phosphorus from biologically treated wastewater is investigated in this article. A phosphate phosphorus concentration was reduced by filtering wastewater through sorbents filter media during the experiment. Concentrations of treated wastewater pollutants, filtration rate, efficiency of sorbents to remove phosphorus from the wastewater were measured and evaluated. Experiment results showed that phosphate phosphorus was effectively removed by Filtralite P sorbent (removal efficiency 97–98%), less effective were foam-glass (removal efficiency 66–95%) and crushed shells sorbents (removal efficiency 39–50%).
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Fadil MOUSA, Enaam, et Ibtissam Khalifa JASSIM. « SYNTHESIS ,CHARACTERIZATION AND BIOLOGICAL ACTIVITY STUDY OF SOME HETEROCYCLIC COMPOUNDS ». Dans IV.International Scientific Congress of Pure,Appliedand Technological Sciences. Rimar Academy, 2022. http://dx.doi.org/10.47832/minarcongress4-18.
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Heterocycles are an important class of organic compounds because of their applications in medicines and industrial fields. Therefore our study included preparation of these compound such as oxazepine and quinazoline rings, which were prepared through two steps: The first step included the reaction of the Schiff bases derived from sulfamethaxazole (1-4) with each of phthalic anhydride and 3- nitrophthalic anhydride for the preparation of oxazepines (5-12) .While the second step included the preparation of quinazoline compounds (13-16) from the reaction of Schiff bases (1-4) with anthranilic acid using dry benzene as a medium and solvent for the reaction. All prepared compounds were characterized by using infrared,proton- nuclear magnetic resonance, mass techniques and melting points, and their purity was determined by thin layer chromatography technique also screened the biological activity of some of these prepared compounds by using two types of bacteria Gram-positive and negative . The results showed that these compounds have a good inhibition against these organisms
Rapports d'organisations sur le sujet "Biologically important compounds"
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Terah, E. I. Video lectures on the discipline of «Chemistry» for students of specialty «Dentistry». SIB-Expertise, avril 2022. http://dx.doi.org/10.12731/er0555.13042022.
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There are video lectures on chemistry for students of the specialty "Den-tistry": 6 lectures on general chemistry and 11 lectures on bioorganic chemistry. The total duration of the video lectures is 13 hours 17 minutes. In lectures on general chemistry, the basic provisions of chemical ther-modynamics and kinetics, chemical equilibrium, dispersed systems, solutions and their properties, ionic equilibria in solutions of elektrolites, buffer solutions, hydrolysis are considered. Lectures on bioorganic chemistry discuss the properties and importance of biologically important compounds, including proteins, carbohydrates, nucleic acids and fats, as well as issues of lipid peroxidation, antioxidant protection.
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Galili, Gad, Harry J. Klee et Asaph Aharoni. Elucidating the impact of enhanced conversion of primary to secondary metabolism on phenylpropanoids secondary metabolites associated with flavor, aroma and health in tomato fruits. United States Department of Agriculture, janvier 2012. http://dx.doi.org/10.32747/2012.7597920.bard.
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• Targeted manipulating Phenylalanine (Phe) synthesis is one of the most powerful strategies to boost the biologically and economically important secondary metabolites, including phenylpropaniods, aromatic volatiles and specialized secondary metabolites. • Over-expression of the petunia MYB transcript factor, ODORANT1 (ODO1), results in significant alterations of the levels of specific phenylpropanoid compounds in plants. • Our previous studies indicated that ectopic expression of the feedback-insensitive AroG could break the bottleneck between primary and secondary metabolisms in tomato, thereby aiding in producing new tomato composition and identifying the unknown roles of multiple key regulators in specialized metabolism. Therefore, combining the AroG and ODO1 is of particular interest for elucidating the combined regulatory role of both of these genes in the Phe metabolic pathway, as well as generating tomato fruits that contain higher levels of secondary metabolites. • Here, we performed the LC-MS and GC-MS analyses on fruits of four tomato genotypes, namely, wild type tomato fruits as well as tomato fruits expressing the AroG, ODO1 and the combination of AroG plus ODO1 (AO) genotypes. Our results elaborated that the levels of many of the Phe-derived metabolites were predominately altered in fruits of the AO genotype, compared to tomato fruits expressing either AroG or ODO1 individually. The levels of most of these metabolites were significantly stimulated, such as Tyrosine (Tyr), coumaric acid and ferulic acid derived metabolites, but the levels of some important secondary metabolites were reduced in the AO transgenic genotypes as compared to either AroG or ODO1 lines. Nevertheless, our results also revealed that the levels of aromatic volatiles were obviously down regulated in the AO, compared to that in AroG transgenic fruits, but were boosted while compared to the wild type and ODO1 transgenic fruits. • Our results suggest that ODO1 expression may also have a negative effect on the production of some of the aromatic volatiles in tomato fruits, indicating that ODO1 acts as an important regulator of the shikimate pathway, which leads to the production of the aromatic amino acids and secondary metabolites derived from them. Key words: AroG, ODO1, tomato, metabolism, shikimate pathway
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Chamovitz, Daniel A., et Zhenbiao Yang. Chemical Genetics of the COP9 Signalosome : Identification of Novel Regulators of Plant Development. United States Department of Agriculture, janvier 2011. http://dx.doi.org/10.32747/2011.7699844.bard.
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This was an exploratory one-year study to identify chemical regulators of the COP9 signalosome. Chemical Genetics uses small molecules to modify or disrupt the function of specific genes/proteins. This is in contrast to classical genetics, in which mutations disrupt the function of genes. The underlying concept is that the functions of most proteins can be altered by the binding of a chemical, which can be found by screening large libraries for compounds that specifically affect a biological, molecular or biochemical process. In addition to screens for chemicals which inhibit specific biological processes, chemical genetics can also be employed to find inhibitors of specific protein-protein interactions. Small molecules altering protein-protein interactions are valuable tools in probing protein-protein interactions. In this project, we aimed to identify chemicals that disrupt the COP9 signalosome. The CSN is an evolutionarily conserved eight-subunit protein complex whose most studied role is regulation of E3 ubiquitinligase activity. Mutants in subunits of the CSN undergo photomorphogenesis in darkness and accumulate high levels of pigments in both dark- and light-grown seedlings, and are defective in a wide range of important developmental and environmental-response pathways. Our working hypothesis was that specific molecules will interact with the CSN7 protein such that binding to its various interacting proteins will be inhibited. Such a molecule would inhibit either CSN assembly, or binding of CSN-interacting proteins, and thus specifically inhibit CSN function. We used an advanced chemical genetic screen for small-molecule-inhibitors of CSN7 protein-protein interactions. In our pilot study, following the screening of ~1200 unique compounds, we isolated four chemicals which reproducibly interfere with CSN7 binding to either CSN8 or CSN6.
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Jurkevitch, Edouard, Carol Lauzon, Boaz Yuval et Susan MacCombs. role of nitrogen-fixing bacteria in survival and reproductive success of Ceratitis capitata, the Mediterranean fruit fly. United States Department of Agriculture, septembre 2005. http://dx.doi.org/10.32747/2005.7695863.bard.
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Objectives: to demonstrate nitrogen fixation in the gut of Ceratitiscapitata, the Mediterranean fruit fly and that fixed nitrogen is important for the fly. Background: Fruit flies (Diptera: Tephritidae) are a highly successful, widespread group of insects causing enormous economic damage in agriculture. They are anautogenous, i.e. the acquisition of nitrogenous compounds by both male and female is essential for the realization of their reproductive potential. Nitrogen, although abundant in the atmosphere, is paradoxically a limiting resource for multicellular organisms. In the Animalia, biological nitrogen fixation has solely been demonstrated in termites. Major achievements and conclusions: We found that all individuals of field-collected medflies harbor large diazotrophicenterobacterial populations that express dinitrogenreductase in the gut. Moreover, nitrogen fixation was demonstrated in isolated guts and in live flies and may significantly contribute to the fly’s nitrogen intake. Specific components of these communities were shown to be transmitted vertically between flies. Moreover, we found that the gut bacterial community changes during the fly’s active season both in composition and complexity. Moreover, strong changes in community structure were also observed between the fly's various developmental stages. An initial analysis using SuPERPCR, a technology enabling the detection of minor populations by selective elimination of the dominant 16S rDNA sequences revealed that Pseudomonasspp. may also be part of the gut community. Implications: The presence of similar bacterial consortia in additional insect orders suggests that nitrogen fixation occurs in vast pools of terrestrial insects. On such a large scale, this phenomenon may have a considerable impact on the nitrogen cycle.
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Israel, Alvaro, et John Merrill. Production of Seed Stocks for Sustainable Tank Cultivation of the Red Edible Seaweed Porphyra. United States Department of Agriculture, 2006. http://dx.doi.org/10.32747/2006.7696527.bard.
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Porphyra species (commonly known as ‘nori’ or ‘purple laver’) are edible red seaweeds rich in proteins, vitamins and other highly valued biogenic compounds. For years Porphyra has been cultured using seeded nets extended in the open sea, and its biomass consumed primarily in the Far East. While demands for international markets have increased steadily at an average of 20% per year, supplies are on the verge and not expected to meet future demands. Alternatively, land-based cultivation of seaweed has become attractive in the mariculture industry since (1) important growth parameters can be controlled, (2) is environmentally friendly and (3) perfectly matches with integrated aquaculture leading to sustainable, high quality products. During the last few years a tank cultivation technology for Porphyra has been developed at the Israeli institution. This technology is based on indoor production of asexual spores and their subsequent growth to 1-2 mm seedlings. The seedlings are then transferred to outdoor tanks and ponds when seawater temperatures drop to 20 °C, or below, and days become shorter during winter time. However, the current technology efficiently serves only about 100 m2 of ponds during one growth season. In order to produce seedlings in sufficient amounts, it is critical to address both technical and biological aspects of seedling production, securing optimal up-scale to commercial-size cultivation farms. We hypothesize that massive production of spores is related to thalli origin, thalli age and sporulation triggers, and that seedling survival and their subsequent growth potential is determined by the seawater quality and overall indoor growth conditions imposed. A series of bio-reactors were constructed and tested in which spore release and spore growth were separately studied. The main assessment criteria for optimal viability of the seedlings will be by determining their electron transport rate using PAM fluorometry and by subsequent growth and biomass yields in outdoor ponds. Altogether the project showed (1), controlled sporulation is possible in big outdoor/growth chamber settings provided initial stock material (small frozen seedlings) is at hand, (2), contamination problems can be almost completely avoided if stock material is properly handled (clean as possible and partially dehydrated prior to freezing), (3), spore release can significantly be enhance using high nutrient levels during thawing for P. yezoensis and P. haitanensis, but not for P. rosengurttii, (4), PAM fluorometry is an efficient tool to estimate growth capacity in both seedlings and juvenile thalli. The BARD funding also served to explore other aspects of Porphyra biology and cultivation. For example, the taxonomical status of Porphyra strains used in this study was defined (see appendix), and the potential use of this seaweed in bioremediation was well substantiated. In addition, BARD funding supported a number of opportunities and activities in the Israeli lab, direct or indirectly related to the initial objectives of the project such as: additional molecular work in other seaweeds, description of at least 2 new species for the Israeli Mediterranean, and continuous support for the writing of a book on Global Change and applied aspects of seaweeds. The technology for Porphyra cultivation in land-based ponds is readily available. This study corroborated previous know-how of Porphyra growth in tanks and ponds, and yet offers important improvements regarding seedling production and their handling for successful cultivation. This study supported various other activities opening additional important issues in the biology/cultivation/use of Porphyra and other seaweeds.
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Lichter, Amnon, Joseph L. Smilanick, Dennis A. Margosan et Susan Lurie. Ethanol for postharvest decay control of table grapes : application and mode of action. United States Department of Agriculture, juillet 2005. http://dx.doi.org/10.32747/2005.7587217.bard.
Texte intégralRésumé :
Original objectives: Dipping of table grapes in ethanol was determined to be an effective measure to control postharvest gray mold infection caused by Botrytis cinerea. Our objectives were to study the effects of ethanol on B.cinerea and table grapes and to conduct research that will facilitate the implementation of this treatment. Background: Botrytis cinerea is known as the major pathogen of table grapes in cold storage. To date, the only commercial technology to control it relied on sulfur dioxide (SO₂) implemented by either fumigation of storage facilities or from slow release generator pads which are positioned directly over the fruits. This treatment is very effective but it has several drawbacks such as aftertaste, bleaching and hypersensitivity to humans which took it out of the GRAS list of compounds and warranted further seek for alternatives. Prior to this research ethanol was shown to control several pathogens in different commodities including table grapes and B. cinerea. Hence it seemed to be a simple and promising technology which could offer a true alternative for storage of table grapes. Further research was however required to answer some practical and theoretical questions which remained unanswered. Major conclusions, solutions, achievements: In this research project we have shown convincingly that 30% ethanol is sufficient to prevent germination of B. cinerea and kill the spores. In a comparative study it was shown that Alternaria alternata is also rather sensitive but Rhizopus stolonifer and Aspergillus niger are less sensitive to ethanol. Consequently, ethanol protected the grapes from decay but did not have a significant effect on occurrence of mycotoxigenic Aspergillus species which are present on the surface of the berry. B. cinerea responded to ethanol or heat treatments by inducing sporulation and transient expression of the heat shock protein HSP104. Similar responses were not detected in grape berries. It was also shown that application of ethanol to berries did not induce subsequent resistance and actually the berries were slightly more susceptible to infection. The heat dose required to kill the spores was determined and it was proven that a combination of heat and ethanol allowed reduction of both the ethanol and heat dose. Ethanol and heat did not reduce the amount or appearance of the wax layers which are an essential component of the external protection of the berry. The ethanol and acetaldehyde content increased after treatment and during storage but the content was much lower than the natural ethanol content in other fruits. The efficacy of ethanol applied before harvest was similar to that of the biological control agent, Metschnikowia fructicola, Finally, the performance of ethanol could be improved synergistically by packaging the bunches in modified atmosphere films which prevent the accumulation of free water. Implications, both scientific and agricultural: It was shown that the major mode of action of ethanol is mediated by its lethal effect on fungal inoculum. Because ethanol acts mainly on the cell membranes, it was possible to enhance its effect by lowering the concentration and elevating the temperature of the treatment. Another important development was the continuous protection of the treated bunches by modified atmosphere that can solve the problem of secondary or internal infection. From the practical standpoint, a variety of means were offered to enhance the effect of the treatment and to offer a viable alternative to SO2 which could be instantly adopted by the industry with a special benefit to growers of organic grapes.