Figure 2.

Yeast uptake assay with a mixture of genistin, daidzin, and glycitin. Metabolites were extracted from the yeast after feeding for 24 h and analyzed using UPLC against the respective standards. It appeared some of the glycosides were converted to aglycones in the yeast by endogenous enzymes. Values obtained from the yeast expressing GmMATEs were normalized to those from the empty vector control (EV) in the same experiment. The relative uptake levels of individual isoflavone species (A–C,E–G) and different isoflavone combinations (D,H,I–L) were determined. Total aglycones (D) refers to the combination of genistein, daidzein, and glyciteins. Total glycosides (H) refers to the combination of genistin, daidzin, and glycitin. The relative uptake level of total aglycones and glycosides is shown in (L). Values shown are the mean of six independent experiments ± SEM. Significant differences compared to EV were determined by Mann-Whitney test. *, p < 0.05; **, p < 0.01; ns, not significant.