Dimeric Abietane Diterpenoids and Sesquiterpenoid Lactones from Teucrium viscidum

A new abietane diterpenoid, teuvisone (2), a pair of new dimeric abietane diterpenoid stereoisomers, biteuvisones A (3) and B (4), and three new sesquiterpenoid lactones, teuvislactones A-C (6, 7, and 10), were isolated from the whole plants of Teucrium viscidum, along with four known terpenoids (1, 5, 8, and 9). The structures of the new compounds were elucidated by spectroscopic analysis, and the absolute configurations of 5-10 were determined by electronic circular dichroism analysis. The isolated compounds were evaluated for their cytotoxic effects against five human cancer cell lines and for their α-glucosidase inhibitory effects.