Triterpenoid saponins from Meryta lanceolata

Four new oleanane-type saponins and a known one were isolated from the leaves and stems of Meryta lanceolata. The new saponins were characterised by spectroscopic means and chemical hydrolysis as 3-O-{β-d-glucopyranosyl-(1→3)-β-d-glucopyranosyl-(1→3)-[β-d-glucopyranosyl-(1→2)]-α-l-arabinopyranosyl}oleanolic acid 28-O-[α-l-rhamnopyranosyl-(1→4)-β-d-glucopyranosyl-(1→6)-β-d-glucopyranosyl] ester, 3-O-{β-d- glucopyranosyl-(1→3)-β-d-glucopyranosyl-(1→3)-[β-d-glucopyranosyl-(1→2)]-α-l-arabinopyranosyl}oleanolic acid 28-O-[α-l-rhamnopyranosyl-(1→4)-β-d-6-O-acetyl glucopyranosyl-(1→6)-β-d-glucopyranosyl] ester, 3-O-[β-d-glucopyranosyl-(1→2)-β-d-glucopyranosyl-(1→3)-β-d-glucopyranosyl-(1→3)-α-l-arabinopyranosyl]oleanolic acid 28-O-[α-l-rhamnopyranosyl-(1→4)-β-d-glucopyranosyl-(1→6)-β-d-glucopyranosyl] ester and 3-O-[β-d-glucopyranosyl-(1→2)-β-d-glucopyranosyl-(1→3)-β-d-glucopyranosyl-(1→3)-α-l-arabinopyranosyl]echinocystic acid 28-O-[α-l-rhamnopyranosyl-(1→4)-β-d-glucopyranosyl-(1→6)-β-d-glucopyranosyl] ester. The NMR assignments were made by means of HOHAHA, 1H–1H COSY, HMQC, HMBC and NOE difference studies. [Copyright &y& Elsevier]