Effects of Ionizing Radiations on L- and DL-tyrosine Studied by Ultra-violet and Infra-red Spectrophotometry

Summary

Solutions of L- and DL-varieties of tyrosine were irradiated by γ-rays from ⁶⁰Co, and samples of L-tyrosine by β, γ-radiations from radon glass capillaries. Marked changes in both ultra-violet and infra-red spectra were observed. L- and DL- varieties irradiated with ⁶⁰Co γ-radiations do not show significant differences in radiation sensitivity; both gave G-values ≈ 3. Greater radiosensitivity towards β-rays is indicated in the results. The evidence presented for radiation effect suggests (i) de-amination, (ii) formation of intermediary compounds with increased OH attachment to the benzene nucleus and (iii) compounds with C-O-C in the ring among the end-products. Probable mechanisms are discussed.