combretastatin A-4

Combretastatin A-4 (CA4) is a **natural cis-stilbene compound** originally isolated from the African bush willow (*Combretum caffrum*). It acts primarily as a **vascular-disrupting agent** with potent **anti-angiogenic and antitumor activity**. CA4 exerts its activity by binding to the **colchicine-binding site on β-tubulin**, thereby inhibiting tubulin polymerization, which destabilizes microtubules in newly formed endothelial cells of tumor vasculature, leading to selective shutdown of blood supply in tumors and subsequent tumor necrosis. CA4 itself has very limited water solubility, so a phosphate prodrug (CA4P, combretastatin A-4-phosphate) has been developed for clinical trials, where it is rapidly converted in vivo to the active CA4 compound. CA4 and its prodrugs have been evaluated in clinical trials for various cancers, particularly as vascular-disrupting agents in solid tumors.

Other names

cis-combretastatin A-4CA-4CA4CA 4