نتایج جستجو برای: pyrrolidine 1 dithiocarboxylic acid ammonium
تعداد نتایج: 3308511 فیلتر نتایج به سال:
A new pyrrolidine alkaloid codonopsinol C (1), and pyrrolidine alkaloidal glycoside, codonopiloside A (2), were isolated from the roots of Codonopsis pilosula, along with four known pyrrolidine alkaloids, codonopsinol A (3), codonopsinol B (4), codonopyrrolidium B (5), and radicamine A (6). The structures of the new compounds were established by acid hydrolysis and spectroscopic methods. We des...
a method for the degradation of pyrrolidine in water is described. the method relaies on the photocatalytic degradation of pyrrolidine to co2 and nh3 by uv irradiation and using titanium dixide semiconductor as a photocatalyst. compared with direct photolysis, the semiconductor catalytic photolysis gave consistently higher degradation yields for pyrrolidine in water. the effects of variable par...
We analyzed a recently reported (K. Seno, T. Okuno, K. Nishi, Y. Murakami, F. Watanabe, T. Matsuur, M. Wada, Y. Fujii, M. Yamada, T. Ogawa, T. Okada, H. Hashizume, M. Kii, S.-H. Hara, S. Hagishita, S. Nakamoto, J. Med. Chem. 43 (2000)) pyrrolidine-based inhibitor, pyrrolidine-1, against the human group IV cytosolic phospholipase A2 K-isoform (cPLA2K). Pyrrolidine-1 inhibits cPLA2K by 50% when p...
The development of enantioselective anti-selective Mannich-type reactions of aldehydes and ketones with imines catalyzed by 3-pyrrolidinecarboxylic acid and related pyrrolidine derivatives is reported in detail. Both (3R,5R)-5-methyl-3-pyrrolidinecarboxylic acid and (R)-3-pyrrolidinecarboxylic acid efficiently catalyzed the reactions of aldehydes with alpha-imino esters under mild conditions an...
A sensitive method was developed to speciate and quantify As(III) and As(V) in fruit juices. At pH 3.0, As(III) and ammonium pyrrolidine dithiocarbamate (APDC) formed a complex, which was extracted into CCl4 by dispersive liquid-liquid microextraction (DLLME) and subsequently quantified by hydride generation-atomic fluorescence spectrometry (HG-AFS). After As(V) was reduced by thiosulphate at p...
A simple, sensitive and low cost, flow injection time-based method was developed for on-line preconcentration and determination of copper, lead and chromium(VI) at sub mug l(-1) levels in natural waters and biological samples. At the optimum pH, the on-line formed metal-ammonium pyrrolidine dithiocarbamate (APDC) complexes were sorbed on the unloaded commercial polyurethane foam (PUF), and subs...
The fragmentation of peptides containing quaternary ammonium group, but lacking easily mobilizable protons, was examined with the aid of deuterium-labeled analogs and quantum-chemical modeling. The fragmentation of oligoproline containing quaternary ammonium group involves the mobilization of hydrogens localized at α- and γ- or δ-carbon atoms in the pyrrolidine ring of proline. The study of the...
A systematic study on the electrochemical behavior of the S-derivatives of 2-amino cyclopentene-1-dithiocarboxylic acid (ACDA) has been carried out in aqueous ethanolic solutions by means of polarography, coulometry and voltammetry. All the compounds studied exhibited a well defined anodic wave corresponding to a diffusion controlled process. Controlled potential coulometry gave n=1 per mol...
a systematic study on the electrochemical behavior of the s-derivatives of 2-amino cyclopentene-1-dithiocarboxylic acid (acda) has been carried out in aqueous ethanolic solutions by means of polarography, coulometry and voltammetry. all the compounds studied exhibited a well defined anodic wave corresponding to a diffusion controlled process. controlled potential coulometry gave n=1 per mole fo...
A new, high yielding method for the preparation of vasicinone (7) is described. Reaction of 2-nitrobenzoic acid with N, N¢-carbonyldiimidazole followed by 2-pyrrolidinone gave 1-(2-nitrobenzoyl)pyrrolidine-2-one (3). Reduction of the latter with 10% Pd-C afforded deoxyvasicinone (4). Reaction of deoxyvasicinone (4) with bromine yielded monobromo-deoxyvasicinone (5). Exchange of bro...
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