ansamitocin

Ansamitocins are a group of potent benzenic ansamycin antibiotics, specifically maytansinoids, originally isolated from the Gram-positive bacterium *Actinosynnema pretiosum*. They function as highly effective microtubule-disrupting agents by binding to the vinblastine-binding site on tubulin, which inhibits microtubule assembly and leads to cell cycle arrest in the G2/M phase. While their extreme systemic toxicity precludes their use as standalone chemotherapeutic agents, ansamitocins (particularly ansamitocin P-3) serve as essential precursors for the synthesis of thiol-containing maytansinoids like DM1 (mertansine) and DM4. These derivatives are widely utilized as cytotoxic payloads in antibody-drug conjugates (ADCs), such as ado-trastuzumab emtansine. Hisun Pharmaceutical is a major commercial manufacturer of ansamitocin API for the pharmaceutical industry.

Other names

ansamitocin P-3maytansinoid