(-)-Epothilone A

Epothilone A exhibits kinetics similar to paclitaxel by inducing tubulin polymerization in vitro and producing enhanced microtubule stability and bundling in cultured cells. In contrast to paclitaxel, Epothilone A exhibits a greater cytotoxicity against P-glycoprotein-expressing multidrug resistant cells (IC50= 20 nM for MDR CCRF-CEM/VBL100 cells).Epo A is cytotoxic to human T-24 bladder carcinoma cells (IC50 = 0.05 µM in vitro) but has poor pharmacological properties and is 2-fold less potent in stabilizing microtubules compared to epothilone B. (-)-Epothilone A is a microtubule stabilizing agent. (-)-Epothilone A is a Tubulin inhibitor.