Glucosinolate profile of barbarea vulgaris seeds evaluated by lc-esi-fticr mass spectrometry

An important group of bioactive components occurring in Barbarea vulgaris seeds are glucosinolates (GLSs), which are sulfur-rich plant secondary metabolites (1). B. vulgaris is a vegetable belonging to Brassicaceae family and considered as a food supplement. Liquid chromatography with electrospray ionization coupled with Fouriertransform ion cyclotron resonance mass spectrometry (LC-ESI-FTICR MS) and tandem MS, performed by infrared multiphoton dissociation (IRMPD) in the high-resolution trapping cell, were employed to identify GLSs and their derivatives in extracts of B. vulgaris seeds. Along with most common GLSs and derivatives already found in B. vulgaris seeds such as glucoarabihirsuin, glucobarbarin, glucobrassicin, gluconasturtiin, 6’- isoferuloyl-glucobarbarin, 6’-isoferuloyl-glucobrassicin and 6’-isoferuloylgluconasturtiin (2), the occurrence of the uncommon 6’-cumaroylglucobarbarin and 6’-dimethoxycinnamoyl-glucobarbarin is reported. Besides, the presence of five additional GLSs, viz. glucocapparin, sinigrin, glucoelongatin, glucoarabihirin, glucoerucin, was found for the first time. On the basis of their fragmentation behavior, all compounds were successfully identified with mass errors lower than +1.7 ppm. All GLSs and derivative-GLSs were characterized by several product ions, including the HSO4¯ ion at m/z 96.96012, being a good clue for a compound belonging to the GLS family. Moreover, typical fragments derived from thioglucoside moiety and from the side-chain were observed (3,4). It was confirmed that the profiles of isoferuloyl derivatives matched the profiles of non-acylated GSLs (2). (1) D.B. Clarke, Anal. Methods 2 (2010) 310-325. (2) N. Agerbirk, C.E. Olsen, Phytochem. 72 (2011) 610-623. (3) G. Bianco, F. Lelario, F.G. Battista, S.A. Bufo, T.R.I. Cataldi, J. Mass Spectrom. in press DOI 10.1002/jms.2996 (2012). (4) F. Lelario, G. Bianco, S.A. Bufo, T.R.I. Cataldi, Phytochem. 73 (2012) 74-83.