The radiolysis and racemization of leucine on proton irradiation

D- and L-Leucine have been subjected to 39–55 percent radiolysis using 0–11 MeV protons, both with the proton beam passing through the sample or being absorbed by it, and with quenching the sample immediately on completion of irradiation or after a 21-day interval. Racemization was small (1.1–1.7 percent) and comparable in all cases, suggesting that radioracemization and secondary degradative effects were not important factors in our recent unsuccessful attempts to induce optical activity in DL-leucine by partial radiolysis using 0–11 MeV longitudinally polarized protons.