Relationship between free amino acids and glucosinolates in primary and secondary inflorescences of 11 broccoli (Brassica oleracea L var italica) cultivars grown in early and late seasons

Abstract

Amino acids have been identified as the precursors of a class of secondary plant metabolites, the glucosinolates, but there is no report on the relationship between the two in vivo. In this work we have investigated the relationship between free amino acids and glucosinolates in 11 broccoli cultivars grown in early (April–July) and late (August–January) seasons. Free amino acids and glucosinolates were quantified by HPLC in primary and secondary inflorescences at maturity stage. Analysis of the data revealed that no significant correlation exists between free amino acids and glucosinolates, suggesting that the precursors of these compounds might be used during the first step of the biosynthetic process to form intermediates, the aldoximes and thiohydroximates, which will then be used in the second stage of the biosynthesis to form, apart from glucosinolates, other secondary plant metabolites.

© 2001 Society of Chemical Industry