Triterpenoid saponins from the herb Hylomecon japonica

Abstract

Six undescribed triterpenoid saponins, named as hylomeconoside C–H, were isolated from the EtOH extract of Hylomecon japonica. On the basis of spectroscopic and chemical evidence, their structures were identified as 3-O-β-D-galactopyranosyl-(1 → 2)-β-D-glucuronopyranosyl gypsogenin 28-O-α-L-rhamnopyranosyl-(1 → 2)-β-L-arabinopyranoside; 3-O-β-D-galactopyranosyl-(1 → 2)-β-D-glucuronopyranosyl gypsogenin 28-O-β-D-xylopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 2)-β-L-arabinopyranoside; 3-O-β-D-galactopyranosyl-(1 → 2)-[α-L-arabinopyranosyl-(1 → 3)]-β-D-glucuronopyranosyl gypsogenin 28-O-β-D-glucopyranosyl-(1 → 3)-[β-D-xylopyranosyl-(1 → 4)]-α-L-rhamnopyranosyl-(1 → 2)-β-L-arabinopyranoside; 3-O-β-D-galactopyranosyl-(1 → 2)-β-D-glucuronopyranosyl gypsogenin 28-O-β-D-galactopyranosyl-(1 → 3)-[β-D-xylopyranosyl-(1 → 4)]-α-L-rhamnopyranosyl-(1 → 2)-β-D-fucopyranoside; 3-O-α-L-rhamnopyranosyl-(1 → 3)-[β-D-galactopyranosyl-(1 → 4)]-β-D-glucuronopyranosyl quillaic acid 28-O-β-D-galactopyranosyl-(1 → 3)-[β-D-xylopyranosyl-(1 → 4)]-α-L-rhamnopyranosyl-(1 → 2)-β-D-fucopyranoside; 3-O-α-L-rhamnopyranosyl-(1 → 3)-[β-D-galactopyranosyl-(1 → 4)]-β-D-glucuronopyranosyl quillaic acid 28-O-β-D-xylopyranosyl-(1 → 3)-β-D-xylopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 2)-β-D-quinovopyranoside. The 50% EtOH extract showed moderate inhibitory activity on the human cancer cell line HeLa, HepG-2, MCF-7, A549, K562 and TE-1. And these six compounds were tested for cytotoxicity against K562. Among them, hylomeconoside H was found to be the most active on the K562 cell lines (IC50 6.60 μM).