New cassane-type diterpenoids from Caesalpinia bonduc

Abstract

Six new cassane diterpenoids, named caesalls H-M (1-6), were isolated from the seed kernels of Caesalpinia bonduc. Their structures were elucidated on the basis of spectroscopic analysis, mainly NMR and MS. The absolute configurations of compounds 1 and 3 were determined by a single-crystal X-ray study using a mirror Cu Kα radiation and circular dichroism (CD) spectra, respectively. None of the compounds were cytotoxic against HepG-2, MCF-7 and MG-63 cells. © 2014 The Pharmaceutical Society of Japan.