Four new cassane diterpenes from the seeds of Caesalpinia minax

- Four new cassane diterpenes were isolated from the seeds of Caesalpinia minax.
- Their structures were elucidated on the basis of 1D and 2D NMR and mass spectroscopic data analyses.
- The phytochemical investigation further revealed the chemical constituents of Caesalpinia minax.
- The cassane diterpenes are may be regarded as the characteristic constituents of Caesalpinia minax.

In our survey on the chemical composition of traditional Chinese medicines to further elucidate their chemical substances for the treatment of diseases, we investigated the chemical constituents of the seeds of plants Caesalpinia minax. The investigation led to the isolation and identification of four new cassane diterpenes, caesalpines A-D (1-4). Their structures were elucidated on the basis of extensive 1D and 2D NMR (COSY, HMQC, HMBC, and NOESY) and mass (ESIMS and HR-ESIMS) spectroscopic data analyses. The phytochemical results imply that cassane diterpenes are maybe regarded as the characteristic constituents of C. minax.