Cyanogenic Glycosides

Abstract

The occurrence of these cyanogenic glycosides is quite widespread, ranging from the simple bacteria and fungi to the much more specialized higher plants as well as some classes of animals. Unlike in the plant kingdom where cyanogenic glycosides are taxonomically widespread, cyanogens in animals appear to be restricted to the phyllum Arthropoda; the subject has been reviewed by Duffey. As in bacterial and fungal cyanogenesis, higher plants utilize two aromatic protein amino acids and three aliphatic branched-chain protein amino acids (including leucine) for the synthesis of most of the cyanogenic glycosides. The inhibition of seleno-enzymes by the removal of selenium when such enzymes are treated with cyanide is a probable reason why selenium poisoning is protected against by the consumption of food sources containing cyanogenic glycosides. The capacity to hydrolyze cyanogenic glycosides is widely distributed among rumen bacteria, but rumen microbes also have the ability to detoxify cyanide via thiocyanate.