Control in vitro of tocopherol oxidase by light in extracts from leaves of Xanthium strumarium L [proceedings].

the sulphated form of ascorbic acid may play a role in the maintenance of connective tissue, suggested that although 35S-labelled glycosaminoglycans are formed in the presence of ascorbic acid 2-[35S]sulphate, they are not formed by direct transfer of the sulphate moiety from ascorbic acid 2-[35S]sulphate but by a decomposition product of the ester (Shapiro & Poon, 1975). The role of ascorbic acid 2-sulphate in the sulphation of cholesterol is also unclear (Verlangieri & Mumma, 1973). Other investigations on the anti-scorbutic properties of the sulphate ester of ascorbic acid have yielded conflictingresults(Mummaetal., 1972; Campeauetal., 1973). Althoughitis notclaimedthat the work reported here clarifies the role of ascorbic acid sulphate, it may well explain some of the anomalous results obtained by other workers using the 35S-labelled ester. In particular, the work of Hornig (1974) on the metabolic fate of the 35S-labelled ester sulphate in rats and guinea pigs, showing the variations in the extents of secretion and recovery of radioactivity could be rationalized if the 35S-labelled preparation could not be identified with pure L-ascorbic acid 2-[35S]sulphate. It is not suggested that the enterogastric circulation exists for the circulation of the ascorbic acid 2-[3sS]sulphate derivative, but that this compound is utilizing a conservation route normally travelled by naturally occurring compounds. I t seems likely that this circulatory route may be a n important mechanism of conservation for certain biochemicals and might be exploited for the treatment of gastrointestinal disorders.