Four New Flavonoid C-Glycosides Isolated from Achyranthes aspera and Their Nitric Oxide Production Inhibitory Activities.

A chemical study of the methanol extract of the aerial parts of Achyranthes aspera led to the isolation of four new flavonoid C-glycosides (1-4) along with eight known analogs (5-12). Their structures were elucidated by a combination of spectroscopic data analysis, HR-ESI-MS, 1D and 2D NMR spectra. All the isolates were evaluated their NO production inhibitory activity in LPS-activated RAW264.7 cells. Compounds 2, 4, and 8-11 showed significant inhibition with IC50 values ranging from 25.06 to 45.25 µM, compared to that of the positive control compound, L-NMMA, IC50 value of 32.24 µM, whereas the remaining compounds were weak inhibitory activity with IC50 values over 100 µM. This is the first report of 7 from Amaranthaceae family, and 11 from the genus Achyranthes.