1940-01-8Relevant academic research and scientific papers
Aroma compounds generated from thermal reaction of l-ascorbic acid with l-cysteine
Yu, Ai-Nong,Zhang, Ai-Dong
experimental part, p. 1060 - 1065 (2011/12/02)
The reaction of l-ascorbic acid with l-cysteine in heated aqueous solution (141 ± 1 °C) at five different pH values (5.00, 6.00, 7.00, 8.00, or 9.00) for 2 h, resulted in the formation of a complex mixture of aroma volatiles. The volatile compounds generated were analysed by SPME-GC-MS. The results gave 43 aroma compounds. The reaction between l-ascorbic acid and l-cysteine led mainly to the formation of alicyclic sulphur compounds, thiophenes, thienothiophenes, thiophenones, thiazoles and pyrazines, most of which contain sulphur. Many of these volatiles had meaty flavour. The origin of many of the compounds was explained. The studies showed that thienothiophenes and thienones were formed mainly at acidic pH. In contrast, higher pH values could promote the production of thiophenes, thiazoles and pyrazines.
Efficient hydrolysis of dithioacetals by the N-fluoro-2,4,6-trimethylpyridinium triflate-water system
Kiselyov,Strekowski,Semenov
, p. 2151 - 2158 (2007/10/02)
Dithioacetals including 1,3-dithianes and 1,3-dithiolanes are efficiently cleaved by the title reagent system to the parent carbonyl compounds. The cleavage of diprotected symmetrical α-diketones and p-phenylenediketones gives monoketones in good yields. Amide, 1,3-dioxolane, disulfide, ester, ether, hydroxy, nitrile, nitro, and sulfide functions are relatively stable under the cleavage conditions but thiols are oxidized to disulfides.
