Stilbene dimer xylosides and flavanols from the roots of Lysidice rhodostegia and their antioxidant activities
Eight new stilbene dimer xylosides (1–8) and one new flavanol (9), along with seven known ones (10–16) were isolated from the roots of Lysidice rhodostegia. Their structures were elucidated by extensive analysis of spectroscopic data (IR, UV, HR-ESI-MS, 1D and 2D NMR), ECD calculations and acid hydrolysis. Compounds 1–16 were evaluated for their antioxidant activities using DPPH radical-scavenging assay. Especially, compounds 9 and 10 exhibited stronger antioxidant effects than the positive control (vitamin E), with IC50 values of 9.57 ± 1.30 and 13.60 ± 1.47 μM, respectively.
stilbene, dimer, flavanol