16533-72-5Relevant articles and documents
Oxidation of maleic acid by tetraethylammonium chlorochromate in an aquo-acetic acid medium- A kinetic and mechanistic study
Awasthi, Anupam,Tomer, Ashish,Singh
experimental part, p. 431 - 433 (2011/11/14)
The oxidation of maleic acid by tetraethylammonium chlorochromate (TEACC) was studied, in the presence of perchloric acid and in acetic acid-water mixtures (50 % v/v). The reaction is first order with respect to maleic acid, tetraethylammonium chlorochromate and acid. Ionic strength changes have no significant effect on the reactivity. The reaction does not induce polymerization of acrylonitrile. The reaction rates were determined at different temperatures and the activation parameters were computed. The reaction rate increased with increasing amount of acetic acid in the mixture. A suitable mechanism consistent with the observed kinetic results has been proposed.
Design, Synthesis, and Evaluation of Aza-Peptide Epoxides as Selective and Potent Inhibitors of Caspases-1, -3, -6, and -8
James, Karen Ellis,Asgian, Juliana L.,Li, Zhao Zhao,Ekici, ?zlem Do?an,Rubin, John R.,Mikolajczyk, Jowita,Salvesen, Guy S.,Powers, James C.
, p. 1553 - 1574 (2007/10/03)
Aza-peptide epoxides, a novel class of irreversible protease inhibitors, are specific for the clan CD cysteine proteases. Aza-peptide epoxides with an aza-Asp residue at P1 are excellent irreversible inhibitors of caspases-1, -3, -6, and -8 with second-order inhibition rates up to 1 910 000 M-1 s-1. In general, the order of reactivity of aza-peptide epoxides is S,S > R,R > trans > cis. Interestingly, some of the R,R epoxides while being less potent are actually more selective than the S,S epoxides. Our aza-peptide epoxides designed for caspases are stable, potent, and specific inhibitors, as they show little to no inhibition of other proteases such as the aspartyl proteases porcine pepsin, human cathepsin D, plasmepsin 2 from P. falciparum, HIV-1 protease, and the secreted aspartic proteinase 2 (SAP-2) from Candida albicans; the serine proteases granzyme B and α-chymotrypsin; and the cysteine proteases cathepsin B and papain (clan CA), and legumain (clan CD).
Kinetics and mechanism of the oxidation of some unsaturated acids by quinolinium bromochromate
Vyas, Shweta,Sharma, Pradeep K.
, p. 820 - 823 (2007/10/03)
The oxidation of maleic, fumaric, crotonic and cinnamic acids by quinolinium bromochromate (QBC) in dimethylsulphoxide (DMSO) leads to the formation of corresponding epoxide. The reaction is of first order with respect to QBC and the acid. The reaction is catalysed by hydrogen ions. The hydrogen-ion dependence has the form: kobs = a + b [H+]. The oxidation of these acids was studied in nineteen different organic solvents. The solvent effect was analyzed by Kamlet's and Swain's multiparametric equations. Solvent effect indicated the importance of the cation-solvating power of the solvent. A mechanism involving a three-centre transition state has been postulated.