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.