Two novel diterpenes, norcaesalpinin I (1) featuring an unusual ring C-contracted dinorcassane and caesalpinin U (2) possessing a highly oxygenated furanocassane skeleton were isolated from the seeds of Caesalpinia minax. Their structures were determined by different spectroscopic methods. A plausible biosynthetic pathway of 1 was proposed. The cytotoxic activity of compounds 1 and 2 against HepG2 and HeLa human tumor cell lines was evaluated.
Keywords: Biosynthetic pathway; Caesalpinia minax; Cytotoxic activity; Norcassane diterpene.
Copyright © 2014 Elsevier B.V. All rights reserved.