γ-Radiolysis of disulfides in aqueous solution. II. D-Penicillamine disulfide

Abstract

The γ-radiolysis of D-penicillamine disulfide (PenSSPen) in 3 × 10−4 M aqueous solution has been studied under aerated and deaerated conditions. G values were determined for the following products: penicillamine sulfinic acid (PenSO2H), penicillaminic acid (PenSO3H), β-hydroxyvaline (PenOH), 2-amino-3-methylbut-3-enoic acid (HOOC•CH(NH2)•C(CH3)=CH2), penicillamine (PenSH), penicillamine disulfide-S-monoxide (PenS(O)SPen), valine (PenH), penicillamine trisulfide (PenSSSPen), and ammonia. The low yield of PenSO3H in aerated solution indicated that PenSOH did not react with oxygen or O2−. The trisulfide, which was obtained in high yield, was found to come mainly from the reactions:[Formula: see text]Experiments with •OH radicals produced chemically (TiCl3/H2O2) and irradiations with cysteine or penicillamine present were used to confirm these reactions. These and the other reactions were tested with radical scavengers; formate and monochloroacetate ions and nitrous oxide.