The radiolysis of tryptophan and leucine with³²P β-radiation

We have extended earlier experiments on the radiolysis of DL-tryptophan using³²P β-radiation to longer reaction times, observing complete destruction of the tryptophan by secondary, non-radiolytic processes. We have also undertaken the irradiation of DL-leucine with³²P β's at -196°, achieving radiolyses to the extents of ca. 20-30%, but observing no concomittant asymmetric bias. The implications of these observations are discussed with regard to the Vester-Ulbricht mechanism for the origin of optical activity.