Cytotoxic triterpenoid saponins from the stem bark of Antonia ovata

Phytochemical investigation of the MeOH extract of the stem bark of Antonia ovata led to the isolation of four triterpenoid saponins, along with eleven known Compounds Their structures were established by extensive 1D and 2D NMR, as well as HR-MS analysis and acid hydrolysis All isolated saponins contained the same tetrasaccharide chain O-beta-D-xylopyranosyl-(1 -> 2)-O-beta-D-glucopyranosyl-(1 -> 3)-O-[beta-D-glucopyranosyl-(1 -> 2)]-beta-D-glucuropyranoside linked to C-3 of esterified derivatives of R-1-barrigenol. A(1)-barrigenol, barringtogenol C, or camelliagenin Biological evaluation of the Compounds against KB cell line revealed a potent cytotoxic activity with IC50 Values ranging from 3 1 to 6 6 mu M. The known compounds were found to be inactive at 10 mu g/ml concentration. (C) 2009 Elsevier Ltd All rights reserved.