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

A new megastigmane glycoside, (3 S ,4 R, 7 E) -megastigma-5,7-diene-9-one-3,4-diol 3 -O-β -D-apiofuranosyl-(1→2)- β -D-glucopyranoside ( 1 ) and a new cyanogenic glycosyl derivative, ( S )-2-(6' -O-R- rosmarinoyl- β -D-glucopyranosyloxy)-phenylacetonitrile ( 2 ) were isolated from the methanol extract of the Elsholtzia ciliata together with twelve known compounds, 1 -O-β -D-glucopyranosyl-2-hydroxy-4-allylbenzene ( 3 ), citrusin C ( 4 ), 1,2-di -O-β -D-glucopyranosyl-4-allylbenzene ( 5 ), manglieside B ( 6 ), 4-allyl-2-hydroxyphenyl 1 -O-β -D-apiofuranosyl-(1→6)- β -D-glucopyranoside ( 7 ), (-)-isolariciresinol 3α- β -D-glucopyranoside ( 8 ), 7 R ,8 R -threo-4,7,9-trihydroxy-3,3'-dimethoxy-8 -O- 4'-neolignan-9' -O-β -D-glucopyranoside ( 9 ), 7 R ,8 R -threo-4,7,9,9'-tetrahydroxy-3-methoxy-8 -O- 4'-neolignan-9' -O-β -D-glucopyranoside ( 10 ), cedrusin-4 -O-β -D-glucopyranoside ( 11 ), icariside E 3 ( 12 ), everlastoside L ( 13 ) and rosmarinic acid ( 14 ). 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 1 and 2 were successfully indicated by both theoretical and calculated CD spectra. Compounds 3 - 7 , 9 and 10 potential inhibited NO production in LPS-activated RAW264.7 cells with IC 50 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 N G -monomethyl-L-arginine acetate (L-NMMA), IC 50 = 32.51 µM.