Two new cassane-type diterpenes from the seeds of Caesalpinia crista.

Two new cassane-type diterpenes, phangininoxys D and E (1 and 2), together with five known compounds were isolated from the seeds of Caesalpinia crista Linn. The structures of these compounds were elucidated by means of various spectroscopic analyses. All the isolated compounds were evaluated for cytotoxicity activities against HeLa, HT-29 and KB cell lines, and compound 7 showed moderate selective activities against KB cell line with an IC50 value of 17.1 µM.