Five new triterpenoidal saponins from the roots of Ilex cornuta and their protective effects against H₂O₂-induced cardiomyocytes injury.

Five new ursane-type triterpenoidal saponins (1-5), together with five known ones (6-10), were isolated from the EtOH extract of the roots of Ilex cornuta. The structures of saponins 1-5 were elucidated as 19α-hydroxyurs-12-en-28-oic acid 3β-O-β-D-glucuronopyranoside (1), 19α-hydroxyurs-12-en-28-oic acid 3β-O-β-D-glucuronopyranoside-6-O-ethyl ester (2), 19α-hydroxyurs-12-en-28-oic acid 3β-O-α-L-arabinopyranosyl-(1→2)-β-D-glucuronopyranoside (3), 3β-O-[α-L-arabinopyranosyl-(1→2)-β-D-glucuronopyranosyl]-19α-hydroxyurs-12-en-28-oic acid 28-O-β-D-glucopyranosyl ester (4) and 3β-O-[α-L-arabinopyranosyl-(1→2)-β-D-glucuronopyranoside-6-O-methyl ester]-19α-hydroxyurs-12-en-28-oic acid 28-O-β-D-glucopyranosyl ester (5), on the basis of spectroscopic analyses (IR, ESI-MS, HR-ESI-MS, 1D and 2D NMR) and chemical reactions. Protective effects of compounds 1-10 against H₂O₂-induced H9c2 cardiomyocyte injury were tested. Compounds 1-5, 7, and 10 showed cell-protective effects. Among them compound 5 exhibited the highest activity. No significant DPPH radical scavenging activity was observed for compounds 1-10.