Liquid chromatography/mass spectrometry-based structural analysis of soyasaponin Ab metabolites by human fecal microflora

Soyasaponin Ab, a major constituent of soybean by human intestinal microflora, was anaerobically incubated with fecal suspensions from ten individuals for 48 h and its metabolites were measured by LC-MS/MS analysis Ten metabolites were detected The spectra of the parental constituent soyasaponin Ab showed a peak at m/z 1435 [M-H](-) ion and those of its nine metabolites showed peaks at m/z 1310 0 [M-3C(2)H(2)O-H](-) ion, m/z 1267 9 [M-4C(2)H(2)O-H](-) ion, m/z 1105 3 [M-Glc-4C(2)H(2)O-H](-) ion, m/z 973 2 [M-Glc-Ara-4C(2)H(2)O-H](-) ion, m/z 943 4 [M-2Glc-4C(2)H(2)O-H](-) ion, m/z 811 1 [M-2Glc-Ara-4C(2)H(2)O-H](-) ion, m/z 781 2 [M-2Glc-Gal-4C(2)H(2)O-H](-) ion, m/z 649 0 [M-2Glc-Gal-Ara-4C(2)H(2)O-H](-) ion, and m/z 458 8 [Soyasapogenol A + H](+) ion Metabolic activity varied significantly between individuals. The metabolic pathway was classified into two groups the first group potently produced soyasapogenol A and the second group accumulated soyasapogenol A 3-beta-D-glucuronide (C) 2010 Elsevier B V All rights reserved