Macbecin
Macbecins are a pair of chemical compounds in the ansamycin family of antibiotics. They are designated macbecin I and macbecin II and they were first isolated from actinomycete bacteria. Macbecin possesses antitumor properties. In vitro studies have shown that macbecins are effective in the eradication of Gram-positive bacteria, fungi, and protozoa including Tetrahymena pyriformis.