New cassane- and norcassane-type diterpenoids from the seed kernels of Caesalpinia sinensis and their anti-inflammatory activity in vitro

The first investigation of phytochemistry on the seed kernels of Caesalpinia sinensis led to the isolation and characterization of six new compounds including three tricyclic-type cassane diterpenoids ( 1 ‐– 3 ) and three norcassane-type diterpenoids ( 4 – 6 ), together with three know compounds ( 7 – 9 ). Compounds 1 – 9 represented the first discovery of cassane-type diterpenoids from C. sinensis. Their structures were elucidated by a...