A new lignan with hypoglycemic activity from Tadehagi 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 (1H and 13C APT, HSQC, HMBC, 1H–1HCOSY, 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.