Biological Interactions Of Sulfur Compounds

Author: Stephen C. Mitchell
Publisher: CRC Press
ISBN: 1482272598
Format: PDF, ePub, Mobi
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This text focuses on the biological interactions of sulphur compounds which arise specifically from the presence of the sulphur atom within the molecule. The book opens with introductory chapters on the chemistry and biology of sulphur, before tackling the field by introducing compounds which share a common chemical combination. In general, following a description of the uses and impact upon the biological field, specific chemical group characteristics are discussed together with the biological activity and structure-activity relationships where known. The toxicity of such compounds, their consequences in biochemical and clinical terms, and their mechanisms of biological interaction are then addressed.

Chemico biological Interactions of Sulfide and Organosulfur Compounds microform

Author: Mohammad Ali Eghbal
Publisher: National Library of Canada = Bibliothèque nationale du Canada
ISBN: 9780612916364
Format: PDF
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Exposure of isolated hepatocytes to NaHS led to GSH depletion. CYP450 inhibitors were protective against NaHS toxicity and prevented GSH depletion. Methionine was protective against NaHS and its effect was overcome by inhibition of S-adenosyl-L-homocysteine hydrolase by adenosine. This suggests that S-adenosyhnethionine dependent methylation can detoxify H2S in the liver. The H 2O2 scavengers were protective against H2S toxicity. H2S induced ROS formation was dose dependent and pyruvate inhibited this ROS production. Nontoxic concentrations of H2S enhanced the cytotoxicity of H2O2 generated by glucose/glucose oxidase, which was inhibited by CYP450 inhibitors. Furthermore hepatocyte ROS formation induced by H2S was decreased by CYP450 inhibitors cimetidine and benzyleimidazole. Therefore CYP450-dependent metabolism of H2S is responsible for inducing ROS production. H2S induced cytotoxicity was preceded by mitochondrial depolarization. In this project, two aspects of the action of hydrogen sulfide and reactive sulfur species have been studied: cytotoxic and cytoprotective effects. Freshly isolated hepatocytes have been used in order to examine the prevalence and mechanisms of the different sulfide dependent processes that influence cell survival and death. Our hypothesis is that the exogenous application of high concentrations of HS and other reactive sulfur species to isolated hepatocytes in the presence of various modulators will provide a rapid mechanism dependent screen for ways in which reactive sulfur species can modulate cell survival and death. NaHS and/or garlic/onion derived organosulfur compounds, Allyl mercaptan (AM) and Propyl mercaptan (PM) protected hepatocytes against hydroquinone, methylbenzoquinone, and 5-hydroxynaphtoquinone. NaHS and mercaptans increased the cytotoxicity of tert-butylhydroquinone. Treatment of these benzoquinones with allyl mercaptan, propanethiol or NaHS led to formation of new compounds which by MS/MS analysis were identified as mercaptan conjugates of corresponding hydroquinones. (Abstract shortened by UMI.)H2S, allyl mercaptan (AM), propyl mercaptan (PM), diallyl disulfide (DADS) and diallyl sulfide (DAS) prevented hepatocyte toxicity induced by allyl alcohol, 1-bromoethanol and their toxic metabolites. MS/MS spectrometry revealed adduct formation between AM and/or PM with the acrolein and/or haloacetaldehyde formed by the metabolism of allyl alcohol and alpha-haloethanol. H 2S or garlic and onion mercaptans are cytoprotective by trapping toxic aldehyde metabolites and/or by preventing lipid peroxidation.

Chemical Modification of Biological Polymers

Author: Roger L. Lundblad
Publisher: CRC Press
ISBN: 1439849005
Format: PDF, Mobi
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Examining the chemical modification of biological polymers and the emerging applications of this technology, Chemical Modification of Biological Polymers reflects the change in emphasis in this subsection of biotechnology from the study of protein structure and function toward applications in therapeutics and diagnostics. Highlights The basic organic chemistry of the modification proteins, nucleic acids, oligosaccharides, polysaccharides, and their applications New analytical technologies used to characterize the chemical modification of biological polymers Identification of in vivo, non-enzymatic chemical modification of biological polymers Specific chemical modifications to generate biopharmaceutical products This book covers the basics on the organic chemistry underlying the chemical modification of biopolymers, including updates on the use of various chemical reagents. It describes the current status of chemical modification of biological polymers and emerging applications of this technology in biotechnology. These technologies are important for the manufacture of conjugate proteins used in drug delivery, for the preparation of nucleic acid microarrays, and for the preparation of hydrogels and other materials used in tissue engineering.

Volatile Sulfur Compounds in Food

Author: Michael Qian
Publisher: OUP USA
ISBN: 9780841226166
Format: PDF
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This book brings together intelligent insights and approaches from prominent scientists in the fields of food and flavor to bring a deep understanding about the flavor contributions of sulfur compounds.

The Chemistry and Biology of Volatiles

Author: Andreas Herrmann
Publisher: John Wiley & Sons
ISBN: 1119956986
Format: PDF, ePub
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"Coming to a conclusion, this wonderful, informative and very interesting book presents an excellent overview of small volatile organic compounds and their role in our life and environment. Really fascinating is the entirety of scientific disciplines which were addressed by this book." –Flavour and Fragrance Journal, 2011 "… this book deserves to be a well-used reference in the library of any laboratory specialising in VOC". –Chemistry World, 2011 Volatile compounds are molecules with a relatively low molecular weight allowing for an efficient evaporation into the air. They are found in many areas of our everyday-life: they are responsible for the communication between species such as plants, insects or mammals; they serve as flavours or fragrances in many food products or perfumed consumer articles; and they play an important role in atmospheric chemistry. This book takes an interdisciplinary approach to volatile molecules. Review-style introductions to the main topics in volatile chemistry and biology are provided by international experts, building into a broad overview of this fascinating field. Topics covered include: The structural variety of volatile compounds Biogeneration of volatiles Synthesis of natural and non-natural volatiles Analysis of volatiles Volatile compounds as semiochemicals in plant-plant or plant-insect interactions Volatiles in pest control Pheromones and the influence of volatiles on mammals Olfaction and human perception Volatiles as fragrances The generation of flavours and food aroma compounds Stabilisation and controlled release of volatiles The impact of volatiles on the environment and the atmosphere

Sulfur

Author: A. Müller
Publisher: Elsevier
ISBN: 1483289893
Format: PDF
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Sulfur: Its Significance for Chemistry, for the Geo-, Bio- and Cosmosphere and Technology focuses on the significance of sulfur for chemistry, geosphere, biosphere, cosmosphere, and technology. Topics covered range from the geochemistry and natural cycle of sulfur to the role of sulfur in "black powder". Organometallic sulfur compounds, thiolates, and the spectroscopic effects of sulfur chemistry are also discussed. Comprised of 21 chapters, this volume begins with an introduction to elemental sulfur and related homocyclic compounds and ions, focusing on their preparation, molecular and crystal structures, molecular spectra, and thermodynamic properties. Subsequent chapters deal with the origin and natural cycle of sulfur in the earth's crust; the role of sulfur in the reactions of exploding gunpowder; the use of sulfur in artwork; and developments in the field of organic sulfur chemistry. The catalytic properties of metal complexes of sulfur and sulfur-nitrogen compounds are also examined, along with the synthetic aspects of sulfido-complexes of molybdenum and tungsten. The final section is devoted to the role of sulfur in microbiology, biochemistry, and medicine. This monograph will be useful to students, practitioners, and researchers in the field of inorganic chemistry, as well as those who are interested in sulfur and its compounds.

The Chemistry of Organic Sulfur Compounds

Author: Norman Kharasch
Publisher: Elsevier
ISBN: 1483156117
Format: PDF, ePub, Mobi
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The Chemistry of Organic Sulfur Compounds deals with the chemistry of organic sulfur compounds such as thiocyanates, 1-alkynyl thioethers, thiols, and olefins. Topics covered range from the mechanisms of Raney nickel desulfuration to olefin sulfide chemistry, desulfonylation reactions, and alkaline decomposition of aliphatic disulfides. The reaction of cyanide with cystine and cystine peptides is also discussed. This volume is comprised of 15 chapters and begins with an introduction to electron correlation and bond properties in some selected sulfur compounds including thionyl and sulfuryl fluoride. The following chapters explore the mechanisms of Raney nickel desulfuration; isomerization of organic thiocyanates; polyfluoroalkyl derivatives of sulfur; anionic oxidation of thiols and co-oxidation of thiols with olefins; and the chemistry of the 1,2-sithiole ring. Thiohydantoins, thiophosgene, and the alkaline decomposition of aliphatic disulfides are also considered. The final chapter is devoted to oxidation of disulfides, with special reference to cystine. This book will be a useful resource for organic chemists.