Fig. 3

P450 enzymes screening and functional identification. a Overview of the P450 gene screening method. The detailed method is described in Methods. b HPLC analysis of the apigenin-7-O-glucuronide standard, scutellarin standard, the fermented product of the scutellarin-producing strain (SC1-Y22-EbF6H-EbCPR&Y33-EbF7GAT-EbUDPGDH), and the negative control strain (SC1-Y22&Y33). Y22 and Y33 represent the plasmids Ycplac22 and YcplacY33. c MS analysis of scutellarin in the fermented product of the scutellarin-producing strain. d HPLC analysis of microsomal enzyme assays (containing EbF6H and EbCPR) incubated with apigenin in vitro. The microsomal fraction containing only EbCPR was used as negative control. e HPLC analysis of microsomal enzyme assays incubated with apigenin-7-O-glucuronide in vitro. The microsomal fraction containing only EbCPR was used as the negative control