An acetyl flavonol from Nervilia fordii (Hance) Schltr.

A new acetyl flavonol, named 3-O-acetyl-7-O-methyl kaemferol (1), together with the five known compounds rhamnocitrin (2), rhamnocitrin-3-O-beta-d-glucoside (3), rhamnocitrin-4'-beta-d-glucoside (4), rhamnazin (5), and p-hydroxyl benzoic acid (6) was isolated from Nervilia fordii (Hance) Schltr. The structures of the compounds were determined by spectroscopic analysis. All the compounds were evaluated against nitric oxide (NO) release, based on the production of NO in mice RAW264.7 stimulated by lipopolysaccharide (LPS). This new compound (1) showed potent inhibitory activity against the production of NO in RAW264.7 stimulated by LPS with the IC50 value of 16.79 microM.