Spermacosides a and B, two new triterpenoid saponins from Spermacoce ocymoides burm.f.

Two new triterpenoid saponins, named spermacosides A-B ( 1  -  2 ), together with two known oleanane-type triterpenoid saponins, 3- O - β- D-xylopyranosyl-(1→3)- β- D-glucopyranosylbayogenin ( 3) and 3- O - β -D-glucopyranosylbayogenin ( 4 ), were isolated from the ethyl acetate extract of Spermacoce ocymoides Burm.f. in a phytochemical investigation. Their chemical structures were elucidated by spectroscopic data analysis (1D and 2D NMR, and HR-ESI-MS), as well as comparison with reported data. All these compounds were evaluated for inhibiting nitric oxide production in lipopolysaccharide-stimulated RAW 264.7 cells. Among them, 1 showed a slight effect with an IC50 value of 108.65 ± 7.91 µM, and compounds 2-4 were inactive.