- STUDIES ON THE REACTIONS OF SELENITE ION WITH 1,2-DIMERCAPTOETHANE OR THIOACETIC ACID
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The reactions are reported between selenite and 1,2-dimercaptoethane (DME) or thioacetic acid (TAA) to form moderately stable derivatives having an enhanced absorptions in the 230-360 nm region in combining molar ratios 3:2 and 4:1, respectively.Both reactions invariably yield one product corresponding to the selenium-containing derivative of DME or TAA.The formation of products is a pH dependent process.The equilibrium constants of reactions between selenite and DME or TAA were measured.
- Czauderna, Marian,Samochocka, Krystyna
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- Identification of new anti-inflammatory agents based on nitrosporeusine natural products of marine origin
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Nitrosporeusines A and B are two recently isolated marine natural products with novel skeleton and exceptional biological profile. Interesting antiviral activity of nitrosporeusines and promising potential in curing various diseases, evident from positive data from various animal models, led us to investigate their anti-inflammatory potential. Accordingly, we planned and synthesized nitrosporeusines A and B in racemic as well as enantiopure forms. The natural product synthesis was followed by preparation of several analogues, and all the synthesized compounds were evaluated for in vitro and in vivo anti-inflammatory potential. Among them, compounds 25, 29 and 40 significantly reduced levels of nitric oxide (NO), reactive oxygen species (ROS) and pro-inflammatory cytokines. In addition, these compounds suppressed several pro-inflammatory mediators including inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), nuclear factor-κB (NF-κB), and thereby can be emerged as potent anti-inflammatory compounds. Furthermore, all possible isomers of lead compound 25 were synthesized, characterized and profiled in same set of assays and found that one of the enantiomer (?)-25a was superior among them.
- Philkhana, Satish Chandra,Verma, Abhishek Kumar,Jachak, Gorakhnath R.,Hazra, Bibhabasu,Basu, Anirban,Reddy, D. Srinivasa
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- Photolysis of methyl-parathion thin films: Products, kinetics and quantum yields under different atmospheric conditions
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The present study focuses on the photodegradation of methyl-parathion thin films, an organophosphate insecticide, under different atmospheric conditions. The latter include nitrogenated, oxygenated and ozonated atmospheres, under low and high relative humidity conditions. Addition of oxygen to the atmospheric mixture did not seem to affect the reaction rates and quantum yields. Relative humidity affect was minor, with a small enhancement in reaction rate under 254. nm radiation. The addition of ozone (to either dry or humid atmosphere), at all concentrations tested, largely enhanced degradation rates. In the absence of ozone, the obtained quantum yields for photolysis of methyl-parathion thin films under 254 and 313. nm were 0.024 ± 0.007 and 0.012 ± 0.005, respectively. These values are higher than the values previously reported for solutions of methanol and water. Although the presence of molecular oxygen and water vapors did not seem to affect much the reaction rates, it did have a certain effect on the resulted products. More polar products were obtained under oxygenated and ozonated atmospheres, as well as dimers under ozone conditions. The reaction on thin films has yielded more toxic products than usually found in solutions, adding alkylphosphate esters in addition to the oxons formed normally.
- Segal-Rosenheimer, Michal,Dubowski, Yael
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scheme or table
p. 193 - 202
(2010/10/01)
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- METHOD FOR THE PRODUCTION OF A THIOACETIC ACID AND SALTS THEREOF
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The invention relates to a method for the production of an thioacetic acid and salts thereof of formulae (I) and (II), wherein Mn+ represents ammonium or an alkali metal cation, alkaline earth metal cation, aluminium cation or titanium cation, by reacting ketene with hydrogen sulphide in the presence of a nitrogenous base or reacting ketene with an aqueous alkali metal hydrogen sulphide solution. The thioacetic acid thus formed can be, optionally, subsequently transformed into the corresponding salt by reacting it with ammonia or an alkali metal base, alkaline earth metal base, aluminium base or titanium base. The transformation of thioacetic acid and the formation of salt is carried out as a one-pot method.
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Page/Page column 6
(2008/06/13)
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- Generation of thiols by biotransformation of cysteine-aldehyde conjugates with baker's yeast
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Baker's yeast was shown to catalyze the transformation of cysteine-furfural conjugate into 2-furfurylthiol. The biotransformation's yield and kinetics were influenced by the reaction parameters such as pH, incubation mode (aerobic and anaerobic), and substrate concentration. 2-Furfurylthiol was obtained in an optimal 37% yield when cysteine-furfural conjugate at a 20 mM concentration was anaerobically incubated with whole cell baker's yeast at pH 8.0 and 30 °C. Similarly to 2-furfurylthiol, 5-methyl-2-furfurylthiol (11%), benzylthiol (8%), 2-thiophenemethanethiol (22%), 3-methyl-2-thiophenemethanethiol (3%), and 2-pyrrolemethanethiol (6%) were obtained from the corresponding cysteine-aldehyde conjugates by incubation with baker's yeast. This work indicates the versatile bioconversion capacity of baker's yeast for the generation of thiols from cysteine-aldehyde conjugates. Thanks to its food-grade character, baker's yeast provides a biochemical tool to produce thiols, which can be used as flavorings in foods and beverages.
- Huynh-Ba, Tuong,Matthey-Doret, Walter,Fay, Laurent B.,Rhlid, Rachid Bel
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p. 3629 - 3635
(2007/10/03)
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- Methods of immobilizing ligands on solid supports
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A method is provided for immobilizing a ligand, e.g., a nucleic acid, on a solid support. The method includes providing a solid support containing an immobilized latent thiol group, activating the thiol group, contacting the activated thiol group with a nucleic acid comprising an acrylamide functional group, and forming a covalent bond between the two groups, thereby immobilizing the nucleic acid to the solid support. Kits containing the solid supports and method of utilizing the solid supports are also provided.
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- Amino acid derivatives, the process for their preparation and their applications to therapy
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Amino acid derivatives of formula (Ia) and (Ib) and prodrugs thereof containing a group responsible for chelating the zinc atom of enkephalinase and angiotensin convertase enzymes are disclosed as inhibitors of these enzymes.
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- Facile Catalytic Conversion of Carboxylic Acids into Thiocarboxylic S-Acids by the Ph3SbO/P4S10 System
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Thiocarboxylic S-acids 2 are readily prepared by direct sulfuration of the corresponding carboxylic acids 1 catalyzed by Ph3SbO/P4S10 under mild conditions.
- Nomura, Ryoki,Miyazaki, Shin-Ichiro,Nakano, Takahiro,Matsuda, Haruo
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p. 2081 - 2082
(2007/10/02)
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- Triester derivatives of N-phosphonomethylthionoglycine as herbicides
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This invention relates to triester derivatives of N-phosphonomethylthionoglycine which represent a new class of organic chemical compounds. This invention further relates to herbicidal compositions and methods employing such compounds.
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- The Mechanism of Thermal Elimination. Part 14. Pyrolysis of Diacetamide, 2-Acetoxypyridine, Diacetyl Sulphide, and Thioacetic Acid: Possible Involvement of Enol Forms in Gas-phase Eliminations
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In the gas phase, diacetamide undergoes unimolecular first-order elimination to give keten and acetamide with log A 12.42 s-1 and Ea 158.23 kJ mol-1 so that the reaction proceeds via a cyclic six-membered transiton state.At 600 K the reaction is 6.7-fold slower than the comparable pyrolysis of acetic anhydride, but 4.4-fold faster than pyrolysis of diacetyl sulphide.This shows that in contrast to ester pyrolysis, heterolysis of the Cα-X bond in these compounds is relatively unimportant, the major rate-determining step being nucleophilic attack of the carbonyl group upon the β-hydrogen; the nucleophilicity of this carbonyl group is probably enhanced by resonance with the lone pair of the group X.The very high reactivity of the diacetyl compounds relative to their ester equivalents suggests that they pyrolyse via the enol forms.Pyrolysis of diacetyl sulphide is accompanied by first-order decomposition of thioacetic acid (one of the primary reaction products) by a number of pathways which give rise to keten, hydrogen sulphide, carbon oxysulphide, methanethiol, and methyl thioacetate, the latter probably arising from a combination of methanethiol with uncharged thioacetic acid which also accounts for the low stoicheiometry (1.8) of the reaction.The rate of elimination of thioacetic acid is governed by the parameters log A 12.5 s-1 and Ea 175.7 kJ mol-1; slightly different values are obtained from the acid produced by decomposition of diacetyl sulphide viz. 12.5 and 173.1 respectively, probably due to the differing initial proportions of the thiono- and thiolo-forms.Decomposition is much faster than the corresponding reactions acetic acid and diacetamide, probably because the nucleophilicity of the thiol group is not lowered by resonance to the extent that operates for the corresponding nucleophiles in acetic acid and acetamide . 2-Acetoxypyridine also undergoes thermal elimination to 2-pyridone and keten, but satisfactory kinetics could not be obtained, due possibly to surface effects and an equilibrium between the N-acetyl and O-acetyl tautomers.The bulk of the compound is much more stable than diacetamide because it exists largely in the O-acetyl form.
- Taylor, Roger
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- Antimicrobial composition and method containing N-(3,5-dihalophenyl)-imide compounds
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Novel N-(3,5-dihalophenyl)imide compounds, which exhibit a strong antimicrobial activity against microorganisms including phytopathogenic fungi, parasites of industrial products and pathogenic microorganisms, represented by the formula, STR1 wherein X and X' each represent halogens and A represents a substituted ethylene such as chloroethylene, C1 - C4 alkylthioethylene, C1 - C2 alkyl-ethylene or 1,2-di-C1 - C2 -alkyl-ethylene, a cyclopropylene such as 1,3-dimethylcyclopropylene, trimethylene, a cyclohexylene-1,2-, cyclohexenylene-1,2-, cyclohexadienylene-1,2- or o-phenylene. The N-(3,5-dihalophenyl)imide compounds can be obtained by any of methods which produce imide compounds or reaction of an N-(3,5-dihalophenyl)maleimide compound with a mercaptan, a hydrogen halide, phosphorus chloride or thionylchloride.
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- 3-Oxomethyl-2-(1-nitro-2-oxoethylidene)-tetrahydro-2H-1,3-thiazines
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Novel compounds defined in the title, useful as insecticides.
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- Pesticidal compositions containing phosphoric esters and divalent sulphur compounds
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Pesticidal composition comprising: a pesticidal, phosphoric ester the molecule of which has at least one alkyl group of 1 to 3 carbon atoms, 0.05 to 10% of an agent stabilizing the said ester against decomposition by protonisation, together with adjuvants characterized in that the stabilizing agent comprises at least one sulphur compound containing per molecule at least one divalent sulphur atom of which one valence is bonded to an atom chosen from sulphur, carbon, nitrogen, hydrogen, and metals capable of giving a salt, the other valence being bonded to an atom chosen from hydrogen, the carbon atom already noted, a second carbon atom, the nitrogen atom already noted, a second nitrogen atom, the metal atom already noted in the case of a metal of valence greater than one, a second atom of metal and oxygen when the first valence is not attached to an atom of hydrogen, the proportion of sulphur calculated with reference to the weight of the sulphur compound being between 5 and 99%. Process for stabilizing a phosphoric ester of which the molecule possesses at least one alkyl group containing 1 to 3 carbon atoms characterized in that there is added to the phosphoric ester or to a mixture which contains it, 0.05 to 10% calculated on the weight of the phosphoric acid ester of an agent capable of stabilizing the said phosphoric ester against protonisation and comprising at least one sulphur compound such as that defined thereupon.
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- Carbamate pesticidal compositions
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Novel 1,3-oxathiolane and 1,4-oxathiane carbamoyloximes have been found to have exceptional miticidal, insecticidal and nematocidal activity.
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