Alkaloids from Phaeanthus vietnamensis with inhibitory effect on nitric oxide production lipopolysaccharide-stimulated in RAW264.7 macrophages

The chemical study of the acidic extract of Phaeanthus vietnamensis leaves led to the isolation of one new alkaloid, vietnamine A (1) and eight known alkaloids (R,S)-2N-norberbamunine (2), grisabine (3), 1S,1 ' R,O,O '-dimethylgrisabine (4), dauricine (5), neothalibrine (6), vietnamine (7), xylopine (8), and argentinine (9) by NMR and MS and comparing with the data reported in the literature. Compounds 1-9 were evaluated for inhibitory NO production in RAW 264.7 macrophages, LPS-stimulated. Compounds 1-3 significantly inhibited on NO production with the IC50 values of 6.8 +/- 0.9, 9.8 +/- 1.0, and 7.1 +/- 0.4 mu g/ml, respectively.