Screening and Identification of Glyceollins and Their Metabolites by Electrospray Ionization Tandem Mass Spectrometry with Precursor Ion Scanning

Abstract

A method has been developed for screening glyceollins and their metabolites based upon precursor ion scanning. Under higher-energy collision conditions employing a triple quadrupole mass spectrometer in the negative ion mode, deprotonated glyceollin precursors yield a diagnostic radical product ion at m/z 148. We propose this resonance-stabilized radical anion, formed in violation of the even-electron rule, to be diagnostic of glyceollins and glyceollin metabolites. Liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) established that scanning for precursors of m/z 148 can identify glyceollins and their metabolites from plasma samples originating from rats dosed with glyceollins. Precursor peaks of interest were found at m/z 337, 353, 355, 417, and 433. The peak at m/z 337 corresponds to deprotonated glyceollins, whereas the others represent metabolites of glyceollins. Accurate mass measurement confirmed m/z 417 to be a sulfated metabolite of glyceollins. The peak at m/z 433 is also sulfated, but it contains an additional oxygen, as confirmed by accurate mass measurement. The latter metabolite differs from the former likely by the replacement of a hydrogen with a hydroxyl moiety. The peaks at m/z 353 and 355 are proposed to correspond to hydroxylated metabolites of glyceollins wherein the latter additionally undergoes a double bond reduction.

Glyceollin Transport, Metabolism, and Effects on P-Glycoprotein Function in Caco-2 Cells

“…1) was isolated using a procedure developed at the Southern Regional Research Center (ARS, USDA, New Orleans, LA, USA) 6,8 and used in recent studies to evaluate glyceollin effects on glucose disposition in fat cells 10 and metabolism in rat plasma. 11 UV-Vis spectrophotometry at 285 nm allowed an estimation of the proportions of the three isomers used in all experiments: glyceollin I (68%), glyceollin II (21%), and glyceollin III (11%). Genistein was purchased from Indofine Chemical Company (Hillsborough, NJ, USA).…”

“…In a subsequent study, metabolism profiling of the plasma samples collected in the Boué et al study revealed production of several metabolites, including oxidative and direct sulfate conjugation of the phenolic hydroxyl group, suggesting that first-pass intestinal and hepatic metabolism may present a significant barrier to systemic absorption of glyceollin. 11 Much like the work done to characterize the causes of the low oral bioavailability of genistein, 2,3,12 the aim of the present investigation was to begin to understand the intestinal transport and metabolism of glyceollin. For these initial investigations, we used Caco-2 cells.…”

Recent (2000–2015) developments in the analysis of minor unknown natural products based on characteristic fragment information using LC–MS

“…However, many radical product ions are formed by homolytic cleavage in the analysis of natural products using ESI-MS/MS, in contradiction to the even-electron rule. Homolytic cleavage was reported for the even-electron molecular ions generated from various flavonoids (Hvattum & Ekeberg, 2003;Cuyckens & Claeys, 2004;March, Miao, & Metcalfe, 2004a;March et al, 2004bMarch et al, , 2006Parejo et al, 2004;Liu et al, 2005Liu et al, , 2009Shahat et al, 2005;Ablajan et al, 2006;Kang, Hick, & Price, 2007;Davis & Brodbelt, 2008;Zhao et al, 2008;Kite & Veitch, 2009;Vessecchi et al, 2011;Menezes et al, 2013;Xia et al, 2013), carotenoids (van Breemen, Dong, & Pajkovic, 2012Rivera, Christou, & Canela-Garayoa, 2014), alkaloids (Fabre et al, 2000;Joly et al, 2005Joly et al, , 2007Zhang et al, 2008;Deevanhxay et al, 2009;Aguiar et al, 2010), aryl a-primary amino ketones (Fornal, 2013), feruloyl quinic acids (Kuhnert et al, 2010), benzofuran derivatives (Wu et al, 2010a), cipadesin limonoids , glyceollins (Quadri et al, 2013). It seemed that the loss of a methyl radical occurs readily from methoxy groups attached to aromatic rings.…”

Mass spectrometric approaches for the identification of anthracycline analogs produced by actinobacteria

“…[24,25] The precursor ion scan, a focused method, is mainly used to enable the analyses of minor unknown metabolites monitoring diagnostic fragment ions by focusing in the loss of some specific group of the compounds. [23] This scan mode has been applied in structural characterization of small molecules [26] to detect metabolite derivatives in biological samples [27] in protein identification [28] and others; however, its main application is in recognition of group of compounds with specified functional groups present in complex mixtures.…”