Simultaneous Quantification of 22 Glucosinolates in 12 Brassicaceae Vegetables by Hydrophilic Interaction Chromatography–Tandem Mass Spectrometry

Abstract

Glucosinolates, which are unique to Brassicaceae vegetables, have diverse biological activities, including antimicrobial, antioxidant, and anticancer actions. In this study, we applied hydrophilic interaction chromatography–tandem mass spectrometry (HILIC–MS/MS) to the simultaneous quantification of 22 glucosinolates in 12 Brassicaceae vegetables, including pak choi, choy sum, Chinese cabbage, cauliflower, cabbage, broccoli, Kai Lan, Brussels sprouts, rocket salad, daikon radish, red cherry radish, and watercress. Significant differences in concentration and composition of glucosinolates were observed among these vegetables. Cabbage had the highest level of total glucosinolates (μg/g dry weight: 19 551.2 ± 1317.7), whereas Kai Lan had the lowest level (7611.3 ± 868.4). Aliphatic and indole glucosinolates were the major components in the 12 vegetables ranging from 76 to 100%, except watercress (37%). On the basis of the content of glucosinolates, the 12 vegetables were well distinguishable and classified according to their morphological taxonomy. This study presents a HILIC–MS/MS approach for quantification of glucosinolates, and demonstrates the potential of glucosinolate profiles for Brassicaceae species identification.

An Integrated Metabolomics Study of Glucosinolate Metabolism in Different Brassicaceae Genera

“…The results from our principal component analysis (PCA) analysis of the 12 vegetables studied ( Figure 2 ) agreed well with the results from our previous studies [ 30 , 48 ]. In the present study, we are able to distinguish the same 12 vegetables using PCA, based on the profiles of volatile compounds [ 48 ] and glucosinolates [ 30 ]. For volatile organic compounds, 1490 features were subjected to PCA after cleaning the data of features present in blanks and with too low detection frequencies, with the vegetable samples separated into 12 clusters that correspond to each genus.…”

“…The loading plots of PCA as shown in Figure 2 c,d facilitated the visualization of the crucial metabolites for differentiating these Brassicaceae genera. These findings suggest that glucosinolates and their volatile breakdown products could be potential biomarkers for chemotaxonomy, which aligns with classical morphological taxonomy [ 30 ].…”

“…Moreover, the types and abundances of glucosinolates differ significantly among different genera. This is in reminiscence to previous reports that the glucosinolate profiles of Brassicaceae vegetables could be useful for their taxonomical classification, sometimes even at the level of different cultivars [ 30 , 49 , 50 ].…”

“…For volatile metabolites analysis, fresh vegetables were processed and analyzed daily, immediately after being collected from the local supermarkets. The extraction methods and processing of samples for each different type of analysis were done as previously described [ 30 , 48 , 59 ]. Three samples from the same supermarket were purchased on different days and prepared for each of the 12 vegetables for both untargeted and targeted analysis.…”

Induction of Glucoraphasatin Biosynthesis Genes by MYB29 in Radish (Raphanus sativus L.) Roots

“…The GSL composition of radish has been well established from several studies [ 16 , 17 , 18 , 19 , 20 , 21 ]. It contains a specific aliphatic GSL called glucoraphasatin (GRH, 4-methylthio-3-butenyl-GSL), which is only abundant in radish.…”