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.