S-Methyl cysteine sulphoxide

Organosulphur compounds, e.g., S-methyl cysteine sulphoxide (SMCSO) and its metabolite methyl methane thiosulphinate, both naturally occurring compounds present in Brassica vegetables (broccoli, cabbage) were found to inhibit benzo[a]pyrene-induced micronucleus formation in mouse bone marrow by 31 and 33%, respectively, after oral administration (Marks et al. 1993). 

Marks HS, Anderson JA, Stoewsand GS. 1993. Effect of S-methyl cysteine sulphoxide and its metabolite methyl methane thiosulphinate, both occuring naturally in brassica vegetables, on mouse genotoxicity. Food Chem Toxic 31 (7) 491-495. 

Kale contains an imbalance of trace elements such as iodine and manganese and a chemical called S-methyl cysteine sulphoxide (SMCO) very high intakes should be avoided as they can lead to haemolytic anaemia and fertility problems. 

Barsley, E. a. Correlation of the configuration of some sulphoxides with (+)-S-methyl-L-cysteine S-oxide. Tetrahedron 24, 3747 (1968). 

Properties and Reactions of Sulphoxides.—Simple reactions resulting in the reduction of sulphoxides to sulphides, reported recently, concern SnCU-HCl, NaHSOj (SO2 is ineffective), RCS2H, and MeCOCl. During the reaction of butyl methyl sulphoxide with L-cysteine, ( -)-2 ner-captopropionic acid, or other optically active thiols, the (-HR)-sulphoxide accumulates, indicating that the (S)-enantiomer is reduced faster by the thiol. ... 

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