Four new cassane-type diterpenoids from the seed kernels of Caesalpinia cucullata Roxb.

The first investigation of chemical composition in seed kernels of Caesalpinia cucullata Roxb. resulted in the separation of four new cassane diterpenes, including three furanoditerpenes (1, 2 and 4) and one tricyclic type (3). It was the first found cassane diterpenoids from this plant. Their gross structures were elucidated by means of comprehensive spectroscopic analysis (UV, IR, NMR, HRESIMS) as well as electronic circular dichroism (ECD) calculation. The compound 1 possess a rare isomerized dihydrofuran ring in structure framework. In bioassay, compounds 1-4 exhibited moderate anti-inflammatory activity by inhibiting production of NO in LPS-induced RAW 264.7 cells.