Two new norneolignans, (7S,8R)-3-methoxy-3',4,9-trihydroxy-4',7-epoxy-8,3'-neolignane-1'-carboxylic acid (1) and (7R,8R)-3-methoxyl-4,9-dihydroxy-3':7,4':8-diepoxyneolignan-1'-carboxylic acid methyl ester (2) were isolated from Callicarpa kwangtungensis, together with ten known compounds, genistin (3), daidzin (4), silybin A (5), isosilybin A (6), isosilybin B (7), p-hydroxybenzaldehyde (8), syringic acid (9), lanceolatin A (10), icariside C5 (11), and (3S,6E,10R)-10-β-D-glucopyranosyloxy-3,11-dihydroxy-3,7,11-trimethyldodeca-1,6-diene (12). Compounds 1 and 2 were evaluated for their effects on the inhibition of nitric oxide (NO) production in lipopolysaccharide induced RAW264.7 cells. Compounds 1 and 2 exhibited inhibitory activity with IC50 values of 31.45 ± 0.38 and 40.72 ± 0.54 μM, respectively.
Keywords: Callicarpa kwangtungensis; RAW264.7 cells; Verbenacase; nitric oxide; norneolignans.