np050202e_si_001.pdf (102.65 kB)
Cytotoxic Sesquiterpene Lactones from Vernonia pachyclada from the Madagascar Rainforest
journal contribution
posted on 2005-09-23, 00:00 authored by Russell B. Williams, Andrew Norris, Carla Slebodnick, Joseph Merola, James S. Miller, Rabodo Andriantsiferana, Vincent E. Rasamison, David G. I. KingstonBioassay-guided fractionation of the cytotoxic leaf extract of Vernonia pachyclada Baker led to the isolation
of three new sesquiterpene lactones, designated glaucolides K−M (1−3). The structures of the new
compounds were determined using 1D and 2D NMR spectroscopy, and the structure and stereochemistry
of 1 were confirmed by single-crystal X-ray diffraction. Compound 3 showed moderate activity in the
A2780 human ovarian cancer cell line, with an IC50 of 3.3 μM.