Photochemistry and radiation chemistry of sulfur-containing amino acids. New reaction of the 1-propenylthiyl radicals

Abstract

In connection with food-flavor deterioration caused by uv or y irradiation, a new reaction of the 1-propenylthiyl radicals from S-(cts-l-propenyl)-L-cysteine irradiated by uv ray or -ray in oxygen-free aqueous solutions was investigated. The main products, formed via 1-propenylthiyl radicals, in uv photolysis were 1-propene-l-thiol, 2,4dimethylthiophene, 3,4-dimethylthiophene, and 3-methylthiophene, while y radiolysis yielded 1-propene-l-thiol, re-propyl 1-propenyl sulfide (cis and trans), and di-l-propenyl sulfide (cis,cis and cis,trans). Furthermore, cistrans isomerization of 1-propenylthiyl radicals plays an important role in the formation of these products.

Synthesis, molecular modeling and biological evaluation of novel 2-allyl amino 4-methyl sulfanyl butyric acid as α-amylase and α-glucosidase inhibitor

“…The AMSB was prepared according to the method of Nishimura and Mizutani [21] reported for the synthesis of S-(2-Propenyl)-L-cysteine and was obtained as white needles with a yield of 79%. Structural conformation of AMSB was done using FTIR, NMR ( 1 H and 13 C), Mass spectra and elemental analysis.…”

“…2-Allyl amino 4-methyl sulfanyl butyric acid was synthesized by the method of Nishimura and Mizutani [21] with slight modification. To the ice cooled solution of 2-amino-4-(methylthio) butanoic acid, 10.0 g, 0.082 M in NH 4 OH (2 M, 240 ml) was added to 3-bromopropene (15.0 g, 0.12 M) with vigorous stirring.…”

Volatile constituents of the distilled oils of Welsh onions (Allium fistulosum L. variety maichuon) and scallions (Allium fistulosum L. variety caespitosum)

“…Radicals centered at sulfur (Le., RS') are most highly reactive and are encountered only as fleeting intermediates in chemical reactions (Block, 1978). The detection of a thiyl radical and/or polysulfur radicals (R(S)n*) was reported by using an ESR method (Block, 1978;Nishimura and Mizutani, 1975;Nishimura et al, 1973). Figure 2 illustrates the mechanism proposed for the formation of alkyl-substituted 1,2,4-trithiolanes, 1,2,3,5-tetrathianes, and 1,2,3,4,6-~entathiepanes.…”

Thermal Degradation Products ofS-Alkyl-l-cysteine Occurring in theA IliumSpecies withd-Glucose

“…These amino acids were confirmed by an interpretation of their spectral data. 17 . 1S ) 2-Propylthioethanol was synthesized from 0.8 g of sodium dissolved in 250 ml of ethanol, to which was added 1.9 g (0.025 mol) of propyl mercaptan.…”