A new megastigmane glycoside from Akebia quinata

A new megastigmane glycoside, 8 S *,9 R *-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.