Taccalonolide A is a microtubule stabilizer, which is a steroid isolated from Tacca chantrieri, with cytotoxic and antimalarial activities. Taccalonolide A causes G2-M accumulation, Bcl-2 phosphorylation and initiation of apoptosis. Taccalonolide A is effective in vitro against cell lines that overexpress P-glycoprotein (Pgp) and multidrug resistance protein 7 (MRP7), with an IC50 of 622 nM for SK-OV-3 cells.