Studies on the identification, biosynthesis and metabolism of a cyanogenic glucoside in Nandina domestica Thunb

Abstract

The occurrence of a new cyanogenic glucoside, p-glucosyloxymandelonitrile, in young shoots of Nandina domestica Thunb. is reported. The amount of the cyanogen varies from 10-20 per cent of the dry weight in young shoots. The administration of ¹⁴C labelled [¹⁴C]tyrosine shows that this amino acid is effectively incorporated into the aldehyde and nitrile moieties. Though no intermediates have been established, experimental evidence indicates that the C_α-C_β bond of tyrosine remains intact during conversion. The nitrile moiety is further metabolized and is incorporated into the amide carbon of asparagine.