Ginsenosides are the principal bioactive ingredients of Panax ginseng and possess diverse notable pharmacological activities. UDP-glycosyltransferase (UGT)-mediated glycosylation of the C6–OH and C20–OH of protopanaxatriol (PPT) is the prominent biological modification that contributes to the immense structural and functional diversity of PPT-type ginsenosides. In this study, the glycosylation of PPT and PPT-type ginsenosides was achieved using a promiscuous glycosyltransferase (Bs-YjiC) from Bacillus subtilis 168. PPT was selected as the probe for the in vitro glycodiversification of PPT-type ginsenosides using diverse UDP-sugars as sugar donors. Structural analysis of the newly biosynthesized products demonstrated that Bs-YjiC can transfer a glucosyl moiety to the free C3–OH, C6–OH, and C12–OH of PPT. Five PPT-type ginsenosides were biosynthesized, including ginsenoside Rh1 and four unnatural ginsenosides. The present study suggests flexible microbial UGTs play an important role in the enzymatic synthesis of novel ginsenosides.


… Page 6. 6 Chemicals and reagents. PPT and PPT-type ginsenosides (ginsenoside Rh1, ginsenoside F1, and  ginsenoside Rg1) 102 were obtained from Chengdu Biopurify Phytochemicals Ltd. (Chengdu, Sichuan, 103 China). UDP-glucose (UDPG), UDP-galactose (UDP-Gal), 104 …