Clerodane diterpenoids with potential anti-inflammatory activity from the leaves and twigs of Callicarpa cathayana.

Phytochemical investigation of the leaves and twigs of Callicarpa cathayana led to the isolation of six new clerodane diterpenoids, cathayanalactones A-F (1-6), together with seven analogues (7-13). Their structures were established by extensive NMR analyses together with experimental and calculated ECD spectra analyses. Compounds 1, 2, 3, 7 and 11 showed inhibitory activities on lipopolysaccharide-induced nitric oxide production in RAW264.7 cells.