- S-aroylthiooximes: A facile route to hydrogen sulfide releasing compounds with structure-dependent release kinetics
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We report the facile preparation of a family of S-aroylthiooxime (SATO) H2S donors, which are synthesized via a click reaction analogous to oxime formation between S-aroylthiohydroxylamines (SATHAs) and aldehydes or ketones. Analysis of cysteine-triggered H2S release revealed structure-dependent release kinetics with half-lives from 8-82 min by substitution of the SATHA ring. The pseudo-first-order rate constants of substituted SATOs fit standard linear free energy relationships (p = 1.05), demonstrating a significant sensitivity to electronic effects.
- Foster, Jeffrey C.,Powell, Chadwick R.,Radzinski, Scott C.,Matson, John B.
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p. 1558 - 1561
(2014/04/17)
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- Beauveria bassiana ATCC 7159 contains an L-specific α-amino acid benzamidase
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Biotransformation of a series of racemic N-benzoyl α-amino acids by the fungus Beauveria bassiana ATCC 7159 results in isolation of the corresponding D-amino acid benzamides in high enantiomeric purity and yield.
- Holland, Herbert L.,Andreana, Peter R.,Salehzadeh-Asl, Reza,Van Vliet, Aaron,Ihasz, Nancy J.,Brown, Frances M.
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p. 667 - 672
(2007/10/03)
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- Amino Acids, 12. - Syntheses of DL-Cysteines from Acrylic Acid Derivatives
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The addition of sulfenyl chlorides 1 to 2-alkenoic acid esters 2 gives mixtures of 2(3)-chloro-3(2)-thioalkenoic acid esters 3/4, whereas the addition of thiols 7 to methyl 2-chloro-2-propenoate (6) results in the formation of methyl 2-chloro-3-thiopropanoates 3 only.The dependence of the isomerization of 3 to 4 on the reaction conditions was investigated; at higher temperatures the formation of 4 is especially favored.At temperatures below 55 deg C the 2-azido compounds 8 are obtained without isomerization from 3 by reaction with sodium azide in the presence of a PT catalyst.Cysteine derivatives 9 or 10, resp., are obtained by hydrogenation of 8 with H2S/pyridine/H2O or with H2/Re2S; the overall yields of 9 or 10, resp., starting from 6 are as high as 70percent.DL-Cysteine is obtained in good overall yields as hydrochloride hydrate 16 by HCl-catalyzed hydrolysis of the 2-thiazolines 15a*HCl and 15e, which are prepared by HCl-catalyzed addition of thioacetamide (11a) to α-chloroacrylic acid (12) or the amide 13 and consecutive ring closure.
- Effenberger, Franz,Beisswenger, Thomas,Dannenhauer, Fritz
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p. 2209 - 2224
(2007/10/02)
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