Bioactive diarylheptanoids and stilbenes from the rhizomes of Dioscorea septemloba Thunb

The 70% ethanol extract of Dioscorea septemloba rhizomes was subjected to chromatographic columns including silica gel, ODS, D101 resin, Sephadex LH-20 and HPLC, to yield three new diarylheptanoids (1-3) and two novel stilbenes (4 and 5), together with six known ones (6-11). Their structures were elucidated on the basis of extensive 1D NMR (¹H and ¹³C), 2D NMR (COSY, HSQC, HMBC, NOESY), IR, and MS spectroscopic data analyses. Moreover, the in vitro bioactivity screening experiment suggested that compounds 6-8 and 10 could significantly increase the glucose consumption in differentiated L6 myotubes, and that 2, 9-11 displayed triglyceride inhibitory effects in HepG2 cells.