Phytochemical constituents from (Thunb.) Hyl. and their nitric oxide production inhibitory activities.

A new megastigmane glycoside, (3,47-megastigma-5,7-diene-9-one-3,4-diol 3-D-apiofuranosyl-(1→2)--D-glucopyranoside () and a new cyanogenic glycosyl derivative, ()-2-(6'rosmarinoyl--D-glucopyranosyloxy)-phenylacetonitrile () were isolated from the methanol extract of the together with twelve known compounds, 1-D-glucopyranosyl-2-hydroxy-4-allylbenzene (), citrusin C (), 1,2-di-D-glucopyranosyl-4-allylbenzene (), manglieside B (), 4-allyl-2-hydroxyphenyl 1-D-apiofuranosyl-(1→6)--D-glucopyranoside (), (-)-isolariciresinol 3α--D-glucopyranoside (), 7,8-threo-4,7,9-trihydroxy-3,3'-dimethoxy-84'-neolignan-9'-D-glucopyranoside (), 7,8-threo-4,7,9,9'-tetrahydroxy-3-methoxy-84'-neolignan-9'-D-glucopyranoside (), cedrusin-4-D-glucopyranoside (), icariside E (), everlastoside L () and rosmarinic acid (). Their chemical structures were elucidated on the basic of extensive 1D and 2D-NMR experiments, as well as their mass spectroscopic data. The absolute configurations of the compounds and were successfully indicated by both theoretical and calculated CD spectra. Compounds -, and potential inhibited NO production in LPS-activated RAW264.7 cells with IC values of 6.71, 8.97, 12.38, 14.27, 16.13, 13.54, 16.27 µM, respectively, compared to that of the positive control of -monomethyl-L-arginine acetate (L-NMMA), IC = 32.51 µM.