Discovery of Four New Compounds from Macropanax membranifolius and Their Cytotoxic Activity.

A phytochemical investigation of the methanolic extract of the Macropanax membranifolius C.B. Shang leaves led to the isolation of three new flavans, (2R,3R)-4'-O-methylcatechin 5-O-β-D-glucopyranoside (1), (2S,3S)-4'-O-methylcatechin 5-O-β-D-glucopyranoside (2), (2S,3R)-4'-O-methylcatechin 5-O-β-D-glucopyranoside (3), one new triterpene glycoside 3-O-β-D-xylopyranosyl-(1→6)-[β-D-xylopyranosyl-(1→2)]-β-D-glucopyranosyl-oleanolic acid 28-O-β-D-glucopyranoside (4), together with nine known compounds (5-13). Their chemical structures were elucidated based on HR-ESI-MS, NMR spectroscopic data. The absolute configurations of compounds 1-3 were established by electronic circular dichroism (ECD) spectra. At concentration of 20 μM, compounds 1-13 showed the percentages of dead cell in the range of 2.14 % to 33.61 % against KB, HepG2, HL60, P388, HT29, and MCF7 cancerous cell lines by SRB assay.