Dibenzocyclooctadiene lignans from Kadsura coccinea.

In vitro anti-allergic screening of medicinal herbal extracts revealed that the EtOAc extract of the rhizoma of Kadsura coccinea inhibited nitric oxide (NO) production in a lipopolysaccharide and recombinant mouse interferon-γ activated murine macrophage-like cell line, RAW264.7. Further fractionation of the EtOAc extract led to the isolation of two new dibenzocyclooctadiene lignans kadsuralignan G (1) and kadsuralignan L (2), and three known analog compounds. The absolute stereostructures were established by circular dichroism spectra. Both 1 and 2 showed moderate NO production inhibitory activities.