Determination of glucosinolate profiles in Chinese vegetables by precursor ion scan and multiple reaction monitoring scan mode (LC-MS/MS).

摘要

Glucosinolates (GSL) are sulfur-containing secondary metabolites in members of the Brassicaceae. Their biological activity is due to the hydrolysis products released by thioglucosidase. Some of these compounds have toxicological effects but others seem to protect against cancer in humans. In this study, LC-electrospray ionization (ESI) MS was used to describe the GSL profiles of 3 Chinese vegetables. The strategy was based on initially screening for possible glucosinolates via a precursor ion scan mode. Further validation was obtained using the multiple reaction monitoring scan mode. The obtained fragment ions [S=C=NOH]- for m/z 75 and [SO4H]- for m/z 97 were used in both scan modes to reveal the masses of the GSL precursor ions [M-H]-. These results were further validated by comparison to the well known GSL profile of broccoli. The tandem MS experiments in negative ion ESI proved to be sensitive and selective enough to rapidly examine the GSL profiles even of crude plant extracts. These results suggest that this method can adequately characterize the target differences between various GSL distributions in vegetables induced by treatment of methyl jasmonate.