N-]S PHOSPHORYL MIGRATION IN PHOSPHORYL GLUTATHIONE

It was found that in the case of N-(diisopropylphosphoryl) glutathion (reduced form), 2, N-->S phosphoryl migration took place, but not for N,N-bis(diisopropylphosphoryl) glutathion (oxidized form) or N-diisopr opylphosphoryl cysteine. These results were deduced by P-31-NMR tracin g experiments. It was shown that phosphoryl migration was catalyzed by an intramolecular carboxyl group, and a mechanism involving a mixed c arboxyl-phosphoric anhydride was proposed. A competitive reaction betw een the amino and thiol group toward diisopropyl phosphite indicated t hat the phospho-thiol derived from N-(diisopropylphosphoryl) glutathio n (reduced form), 2, did not result from direct phosphorylation of the thiol group. N,S-Bis(diisopropylphosphoryl) glutathion provides an au thentic sample to confirm the migrated phosphoryl thiol product. (C) M unksgaard 1993.