A new lignan with hypoglycemic activity fromTadehagi triquetrum

A new lignan named tadehaginosin, together with a known compound 3,4-dihydro-4-(4'-hydroxyphenyl)-5,7-dihydroxycoumarin, was isolated from the aerial part of Tadehagi triquetrum. The new structure was determined by various spectroscopic techniques ((1)H and (13)C APT, HSQC, HMBC, (1)H-(1)HCOSY, NOESY and HR-ESI-MS). The two isolates were evaluated for their hypoglycemic effects in vitro. Biological investigation showed that both of them possessed the capability to increase glucose consumption by HepG2 cells.