Anti-inflammatory diterpene dimers from the root barks of Aphanamixis grandifolia

A total of 14 new diterpene dimers, aphanamenes C-P ()1-14, with four known homologous compounds were isolated from the root barks of Aphanamixis grandifolia Bl. The structures of these compounds were elucidated by spectroscopic analyses, and their absolute configurations were determined using the CD exciton chirality method. In addition, all the compounds exhibited significant inhibition of lipopolysaccharide-induced nitric oxide production in RAW264.7 macrophages, with IC50 values between 7.75 and 38.23 μM.