Topoisomerase-II-Inhibitory principles from the stems of Spatholobus suberectus

Abstract

Bioassay-guided fractionation of the stems of Spatholobus suberectus led to the isolation of procyanidin B4 (=(+)-catechin-(4→8)-(-)-epicatechin) (1) and (+)-catechin-(4→8)-(+)-catechin(4→8)-(-)-epicatechin (2). These compounds, isolated before from other sources, were found to be highly potent inhibitors of DNA-topoisomerase-II (Topo-II)-mediated KDNA decatenation, with IC50 values of 22.5 ± 2.3 and 21.9 ±2.2 nM, resp. © 2007 Verlag Helvetica Chimica Acta AG, Zürich.