The Metabolism of Aromatic Compounds in Higher Plants VII. THE ORIGIN OF THE NITRILE NITROGEN ATOM OF DHURRIN (β-d-GLUCOPYRANOSYLOXY-l-p-HYDROXYMANDELONITRILE)

Abstract The data obtained in these experiments show that the nitrile nitrogen of dhurrin is directly derived from the α-amino group of l-tyrosine. This is analogous to the retention of the α-amino nitrogen of valine on its conversion to linamarin (6). The biosynthetic route from l-tyrosine to dhurrin must involve the modification of the amino acid in a manner such that the C6-C2-N unit remains intact. 15N analyses of the amino acids isolated after l-tyrosine-14C, 15N feeding suggest that the l-tyrosine-l-alanine transamination couple is more active than the l-tyrosine-l-glutamic acid couple.