Isothiocyanate-targeted submetabolome characterization in edible Brassicaceae and Moringaceae plants

Isothiocyanates (ITCs) are widely distributed in Brassicales vegetables and exhibit promising anticancer benefits. However, in-depth mass spectrometric characterization of ITCs remains scarce. Here, we characterized the MS¹ and MS² features of five representative ITC standards and established a four-step screening workflow. Twelve free ITCs and seven ITC-derived adducts were captured and tentatively annotated. More importantly, we discovered a previously unreported class of covalent ITC-derived adducts. The sulforaphane-goitrin and iberin-goitrin adducts were structurally justified via matching full exciting energy ramp-MS³ spectra and chemical synthesis. Nineteen ITC-related compounds were relatively quantified crossing 76 batches of edible plants from 25 Brassicaceae species and one Moringaceae species. Noteworthily, broccoli seeds were found to be a rich source of ITCs. Together, this study revealed a new class of covalent ITC-derived adducts and the distribution patterns of ITCs in edible plants, providing a chemical basis for future anticancer studies and translational studies on ITCs.