ABSTRACT
Objective: To study coumarins from Notopterygium incisum and their anti-inflammatory effect. Methods: Coumarins were separated and purified by repeated column chromatography on silica gel and HPLC, and their chemical structures were determined by spectral data analyses of MS and NMR. Lipopolysaccharide (LPS)-induced RAW 264.7 macrophage cells accompanying overproduction of pro-inflammatory mediator nitric oxide (NO) were applied to investigate the anti-inflammatory effect of these purified coumarins. Results: Twenty-four coumarins were obtained and identified as isoimperatorin (1), angenomalin (2), psoralen (3), bergapten (4), capillarin (5), osthenol (6), 5-dehydronotopterol (7), anhydronotopoloxide (8), 7'-O-methylnotoptol (9), bergamottin (10), 7-isopentenyloxy-6-methoxy-coumarin (11), pabulenol (12), notopterol (13), demethylfuropinarine (14), notoptol (15), cnidilin (16), 6-isopentenyloxyumbelliferone (17), nodakenitin (18), isopimpinellin (19), nodakenin (20), decuroside V (21), decuroside I (22), marmesin-11-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside (23), and forbesoside (24), respectively. Coumarins 7-10, 13, and 15 exhibited potent inhibitory activity against LPS-induced NO production in RAW 264.7 cells with half maximal inhibitory concentration values from 8.50 to 35.12 μmol/L. Conclusion: Compound 7 is a new natural product; compound 17 is obtained from the roots and rhizomes of N. incisum for the first time; Unsaturated double bond on C-5 in the aromatic ring significantly improved the anti-inflammatory activity of coumarins.