Some Observations on the Action of Alkali upon Cystine and Cysteine.*

The decomposition of cystine by alkaline reagents has received much study, particularly in recent years by Gortner and his collaborators (1) and by Andrews (2). Consideration of the results obtained by these workers leads to the conclusion that the process is far from simple, apparently consisting of a series of successive reactions, possibly accompanied by simultaneous side reactions. The experiments here reported are, in the main, of an orientating character only, having been carried out in the hope of disclosing fresh lines of attack on the general problem. Fate of the Organic Portion of the Molecule.-Investigation of the alkaline decomposition products of cystine and of certain of its derivatives led Baumann and others (3) to the conclusion that the initial product is pyruvic acid,1 which subsequently breaks down under the influence of the alkaline reagent. We have been able to confirm this by the isolation of pyruvic acid p-carboxyphenylhydrazone (which is stable towards alkali) in yields of over 60 per cent from cystine by heating with alkaline plumbite in the presence of sodium phenylhydrazine-p-carboxylate. The same product is obtained in somewhat better yield from cysteine under similar conditions. The phenylhydrazone of pyruvic acid can also be