New lignans from Kadsura coccinea and their nitric oxide inhibitory activities.

In vitro anti-allergic screening of medicinal herbal extracts revealed that the chloroform extract of the rhizoma of Kadsura coccinea inhibited nitric oxide (NO) production in a lipopolysaccharide (LPS) and recombinant mouse interferon-gamma (IFN-gamma) activated murine macrophage like cell line RAW 264.7. Further fractionation of the chloroform extract led to the isolation of three new lignans, including two dibenzocyclooctadiene lignans and one arylnaphthalene lignan, together with other three known dibenzocyclooctadiene lignans. This is the first report of NO production inhibitory activity of Kadsura coccinea and first report about the isolation of arylnaphthalene lignan from K. coccinea.