Caesalpanins A-C, Three Dimeric Cassane Diterpenoids from the Seeds of Caesalpinia sappan L.

Three dimeric cassane diterpenoids, caesalpanins A-C, were isolated from the seeds of Caesalpinia sappan L., as well as three known compounds. Their structures were determined via analysis of 1D-, 2D-NMR, and HR-ESI-MS data. Caesalpanins A and B were the second and third compounds that presented a nitrogen-containing cassane diterpenoid dimer linked through one ether bond between C-19 and C-20'. Caesalpanin B exhibited moderate cytotoxic activity against MCF-7 cell lines with IC50 value of 29.98 μm. Caesalpanins A and B had weak inhibitory effects against LPS-induced nitric oxide (NO) production in RAW 264.7 macrophages at 50 μm with inhibitory rate of 36.01 % and 32.93 %, respectively.