Sesquiterpenoids, phenolic and lignan glycosides from the roots and rhizomes of Clematis hexapetala Pall. and their bioactivities

Abstract

Approximately 17 compounds were isolated from a 60% EtOH aqueous extract of the roots and rhizomes of Clematis hexapetala Pall., including three new guaianolide sesquiterpenoids with 5/7/5-fused rings and 3S-configuration (1–3), five new prenylated tetra-substituted phenolic glycosides (4–8) with 6/6-fused 9H-benzopyran skeleton (5) and 6/7-fused 7,10-dihydro-benzoxepin skeleton (6–8), one new isoferulyl glucoside (9), two new furofuran lignan diglucosides (10–11), and six known compounds. The chemical structures of the new compounds were elucidated via spectroscopic data and electronic circular dichroism (ECD) analyses in combination with a modified Mosher’s method. The possible biosynthetic relationships of prenylated tetra-substituted phenols were postulated. In the in vitro assays, compound 16 exhibited moderate TNF-α secretion inhibitory activity with IC50 value of 3.419 μM. Compounds 14–16 displayed potent PTP1B enzymatic inhibitory activities with inhibition ratios of 48.30–86.00%. And compound 16 showed significant PTP1B enzymatic inhibition with IC50 value of 4.623 μM.