Rifamycin

**Semantic type:** Amino Acid, Peptide, or Protein|Pharmacologic Substance

**Definition:** A natural antibiotic produced by Streptomyces mediterranei, Rifamycin (Ansamycin Family) is a commonly used antimycobacterial drug that inhibits prokaryotic DNA-dependent RNA synthesis and protein synthesis; it blocks RNA-polymerase transcription initiation. Rifamycin has an activity spectrum against Gram-positive and Gram-negative bacteria, but is mainly used against Mycobacterium sp. (especially M. tuberculosis) in association with other agents to overcome resistance. (NCI04)

**Synonyms:** - 5,6,9,17,19,21-hexahydroxy-23-methoxy-2,4,12,16,18,20,22-heptamethyl-2,7-(epoxypentadeca(1,11,13)trienimino)naphtho(2,1-B)furan-1,11(2h)-dione 21-Acetate - M-14 - RIFAMYCIN - Rifamycin SV