Ansamycin should not be confused with Annamycin.
Ansamycins is a family of bacterial secondary metabolites that show antimicrobial activity against many Gram-positive and some Gram-negative bacteria, and includes various compounds, including streptovaricins and rifamycins.[1] In addition, these compounds demonstrate antiviral activity towards bacteriophages and poxviruses.
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They are named ansamycins (from the Latin ansa, handle) because of their unique structure, which consists of an aromatic moiety bridged by an aliphatic chain.[2] The main difference between various derivatives of ansamycins is the aromatic moiety, which can be a naphthalene ring or a naphthoquinone ring as in rifamycin and the naphthomycins.[3] Another variation consists of benzene or a benzoquinone ring system as in geldanamycin or ansamitocin. Ansamycins were first discovered in 1959 by Sensi et al. from Amycolatopsis mediterranei, an actinomycete bacterium.[4]
Rifamycins are a subclass of ansamycins with high potency against mycobacteria. This resulted in their widespread use in the treatment of tuberculosis, leprosy, and AIDS-related mycobacterial infections.[5] Since then various analogues have been isolated from other prokaryotes.