S-Substituted Cysteine Derivatives and Sulfoxides

Sulfinic acids, e.g., L-cysteine sulfinic acid and hypotaurine, and sulfonic acids, e.g., L-cysteic acid and taurine, are naturally occurring products of L-cysteiiie and cysteamine oxygenation. They occur in microorganisms, plants, and animals. 

L-Cysteine is transformed to L-cysteine sulfinic acid and L-cysteic acid. Cysteamine (D 11) yields hypotaurine and taurine (Fig. 189). The latter compounds may be transformed to other secondary products by deamination, thiolation, guanylation, and methylation. L-Cysteine sulfinic acid may be degraded to L-alanine and sulfurous acid, which is oxidized to sulfuric acid. 

Hypotaurine and taurine occur in many tissues and in the urine of animals and human beings (E 1). Taurine is a constituent.of several bile acids formed in animals (D 6.4.4) and is of significance as neurotransmitter (E 3.2). 

Cavallini, D., Gaull, G. E., Zappia, V. (eds.) Natural Sulfur Compounds. Plenum Press, New York 1980 

Huxtable, R., Barbeau, A. (eds.) Taurine. Raven Press, New York 1976 

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S-substituted cysteine derivatives and sulfoxides (D 11.2) L-Methionine-derived secondary products (D 12)... 

D 11.2 S-Substituted Cysteine Derivatives and Sulfoxides D 11.1 Sulfinic and Sulfonic Acids... 

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