Cyanogenesis in the Australian tropical rainforest endemic Brombya platynema (Rutaceae): chemical characterisation and polymorphism

Abstract

This study examined two aspects of cyanogenesis in Brombya platynema F. Muell. (Rutaceae), a subcanopy tree endemic to tropical rainforest in far north Queensland, Australia. First, cyanogenic glycosides in foliage were fractionated and identified. The rare meta-hydroxylated cyanogenic glycoside, holocalin, was identified as the principal cyanogen, and traces of prunasin and amygdalin were detected. This is the first characterisation of cyanogenic constituents within the genus, and to the authors' knowledge, only the third within the Rutaceae, and the order Rutales. Second, variation in cyanogenic glycoside content within a population of B. platynema in lowland tropical rainforest was quanti..