Polyene antimycotic

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

Polyene antimycotics, sometimes referred to as polyene antibiotics, are a class of antimicrobial polyene compounds that target fungi.[1] These polyene antimycotics are typically obtained from some species of Streptomyces bacteria. The polyenes bind to ergosterol in the fungal cell membrane and thus weakens it, causing leakage of K+ and Na+ ions, which may contribute to fungal cell death. Amphotericin B, nystatin, and natamycin are examples of polyene antimycotics. They are a subgroup of macrolides.[2]


Their chemical structures feature a large ring of atoms (in essence, a cyclic ester ring) containing multiple conjugated carbon-carbon double bonds (hence polyene) on one side of the ring and multiple hydroxyl groups bonded to the other side of the ring. Their structures also often have a d-mycosamine (a type of amino-glycoside) group bonded to the molecule.[3] The series of conjugated double bonds typically absorbs strongly in the ultraviolet-visible region of the electromagnetic spectrum, often resulting in the polyene antibiotics having a yellow color.

Chemical structure of Amphotericin B. Amphotericin B is an example of a yellow polyene antimycotic agent. Note the alternating double and single bonds in the center and the mycosamine group in the bottom-right corner.
Chemical structure of Nystatin.
Chemical structure of Natamycin, sometimes called pimaricin.


The natural route to synthesis includes polyketide synthase components.[4]

Other examples of polyenes[edit]


  1. ^ NCBI Bookshelf (1996). "Polyene Antifungal Drugs". The University of Texas Medical Branch at Galveston. Retrieved 29 January 2010. 
  2. ^ Hamilton-Miller (1973). "Chemistry and Biology of the Polyene Macrolide Antibiotics" (PDF). Bacteriological Reviews. American Society for Microbiology. 37 (2): 166–196. PMC 413810Freely accessible. PMID 4578757. 
  3. ^ Solution NMR structure of five representative glycosylated polyene macrolide antibiotics
  4. ^ Khan N, Rawlings B, Caffrey P (Jan 26, 2011). "A labile point in mutant amphotericin polyketide synthases". Biotechnol Lett. 33 (6): 1121–6. doi:10.1007/s10529-011-0538-3. PMID 21267757.