By z.'F. A h r n e d l , A. M. R i z k , F. M. H a m m o u d a and M. M. S e i f E l-N a s r Glucosinolates Glucosinolates, a uniform class of thioglucoside anions (I) (K j a r , 1968), sulphur glucosides o r isothiocyanates producing glucosides are different names of a group of naturally occurring glucosides which contain sulphur atom in its building structure. Glucosinolates are usually hydrolysed with the enzyme myrosinase to mustard oils (isothiocyanates), glucose and sulphate ions. T h e occurrence of pungent principles in numerous higher plants, particularly those belonging to the family Cruciferae, has been recognized since ancient times and has motivated the extensive application in several parts of the world of such plants as potherbs, condiments and remedies (K j z r , 1961). More than a hundred years ago, the sulphur-containing compounds responsible for the production of the biting principles of black and white mustard were isolated in a crystalline form. T h e glucosides encountered thus far have invariably contained D-glucose as the sugar moiety, a fact justifying their designation as glucosides in a stricter sense. I t has been customary to attribute trivial names to the individual parent compounds indicating their botanical provenance and preceded by the prefix gluco-(e.g. glucoiberin (ex lberis), glucotropaeolin (ex Tropaeolurn) etc.). T h e classical glucosides sinigrin and sinalbin represent exceptions to rhis general system of naming. lsothiocyanate Glucosides Occurrence and Distribution Foremost among botanical families containing mustard-oil-producing glucosides are the Cruciferae, Capparidaceae, and Resedaceae (K j a r , 1960; E t tl i n g e r and K j z r , 1967; G m e l i n and K j z r , 1970a and c) generally regarded as a phylogenetic alliance. Sporadic appearance of such glucosides in species belonging t o the families Tropaeolaceae, Saluadoraceae, Caricaceae, Limnanl Deceased in 30. l. 1971.

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