CONJUGATION OF D-BETA-METHIONINE INTO N-MALONYL-BETA-METHIONINE BY NICOTIANA RUSTICA

Intact Nicotiana rustica plants were fed d-β-methionine-methyl-14C and the rate of incorporation of radioactivity into the acidic fraction of methanolic root- and shoot-extracts was investigated. From the radioactive acidic fraction a thioether-positive peak and its sulphoxide were isolated and identified as N-malonyl-β-methionine and its sulphoxide. This was confirmed by comparison with synthetic N-malonyl-dl-, l-, and d-β-methionines and by crystallization of the radioactive thioether-positive spot to constant specific activity. Strong evidence was obtained for the d-configuration of the N-malonyl conjugate. © 1970.