Four new cassane diterpenoids from the seeds of Caesalpinia mimosoides

Four new cassane derivatives (1–4), along with five known compounds (5–9) were isolated from the seeds of Caesalpinia mimosoides. Their gross structures were elucidated by means of comprehensive spectroscopic analysis (UV, NMR, HRESIMS) as well as electronic circular dichroism (ECD) calculations. Compounds 1–3 possessing norcassane‐type skeleton were observed, which was rare structural type in the Caesalpinia genus. The results of biological activity evaluation showed that compounds tested could inhibit the production of NO in LPS‐induced RAW 264.7 cells, especially compound 8 exhibited excellent inhibitory activity, implied that these compounds may be potential anti‐inflammatory candidates.