A new megastigmane glycoside from Akebia quinata

A new megastigmane glycoside, 8S*,9R*-megastigman-3-one-4,6-diene-8,9-diol-9-O-β-D-glucopyranoside, named akequintoside D (1), as well as six known compounds, roseoside II (2), 3-O-caffeoylquinic acid (3), methyl-3-O-caffeoylquinate (4), 3,4,5-trimethoxyphenyl-β-D-glucopyranoside (5), cuneataside D (6), 3,4-dimethoxyphenyl-6-O-(α-L-rhamnopyranosyl)-β-D-glucopyranoside (7) were isolated from the stem of Akebia quinata. The structures of compounds (1-7) were identified based on 1D and 2D NMR, including (1)H-(1)H COSY, HSQC, HMBC and NOESY spectroscopic analyses. The inhibitory activity of these isolated compounds against interleukin-6 (IL-6) production in TNF-α stimulated MG-63 cells was also examined.