Seven new triterpene glycosides, bryoniosides A-G (1-7), have been isolated along with two known triterpene glycosides, cabenoside D (8) and bryoamaride (9), from a methanol extract of the roots of Bryonia dioica. The structures of 1-7 were determined on the basis of spectroscopic and chemical methods. Six compounds, 2, 3, 5, and 7-9, and 11 compounds, 1-9, bryodulcosigenin (10), and bryosigenin (11), respectively, were evaluated for their inhibitory effects on 12-0-tetradecanoylphorbol-13-acetate (TPA)induced inflammation (1 mug/ear) in mice and on Epstein-Barr virus early antigen (EBV-EA) activation induced by TPA. All compounds tested showed marked anti-inflammatory effects, with 50% inhibitory doses (ID50) of 0.2-0.6 mg per ear. In addition, all of the compounds tested except for compound 5 showed potent inhibitory effects on EBV-EA induction (100% inhibition at 1 x 10(3) mol ratiq/TPA).
Efficient O-Glycosylation of Triterpenes Enabled by Protein Engineering of Plant Glycosyltransferase UGT74AC1
wild-type enzyme and conserved regioselectivity. Based on the results of molecular docking and molecular dynamics simulations, it was proposed that the improved enzymatic activity and substrate promiscuity were likely owing to the stable hydrophobic interactions and favorite conformations between the enzyme and substrates. This work has also laid a foundation for the engineering of other plant UGTs for their