Epothilone B (Epo B) is a macrolide that causes the formation of bundles of intracellular microtubules in non-mitotic cells, induces the formation of hyperstable tubulin polymers, and arrests cell cycling in mitosis. It induces mitotic arrest at the G2-M transition in Hs578T and HeLa cells (IC50 = 3 and 32 nM,...

The epothilones are cytotoxic agents from the common soil bacteria Sorangium cellulosum. They have taxol like mechanism as microtubule stabilizers binding to beta tubulin. The cytotoxity of epothilone B was found to be superior than that of taxol.