Two new biologically active triterpene saponins from Acanthophyllum squarrosum

Two novel triterpenoid saponins (1 and 2) have been isolated from the roots of Acanthophyllum squarrosum. The structures were established mainly by a combination of 2D NMR techniques as 3-O-β-D-galactopyranosyl-(1→2)[β-D-xylopyranosyl-(1→3)-β-D-glucuronopyra nosylgypsogenin-28-O-β-D-xylopyranosyl-(1→3)-β-D-xylopyranosyl-(1→4)-α-L -rhamnopyranosyl-(1→4)-[α-L-rhamnopyranosyl-(1→3)]-β-D-fucopyranoside (1) and 3-O-β-D-glucopyranosylgypsogenin-28-O-α-L-rhamnopyranosyl-(1→2)-α-L-arabi nopyranosyl-(1→2)-[β-D-glucopyranosyl-(1→6)]-β-D-glucopyranoside (2). Compound 1 showed a moderate concentration-dependent immunomodulatory effect in an in vitro lymphocyte proliferation assay.