Polyketide

Polyketides are secondary metabolites from bacteria, fungi, plants, and animals. Secondary metabolites seem to be unnecessary for an organism’s ontogeny, but appear to have applications such as defence and intercellular communication. Polyketides are derived from the polymerization of acetyl and propionyl subunits in a similar process to fatty acid synthesis. They also serve as building blocks for a broad range of natural products or are derivatized.

Polyketides are structurally a very diverse family of natural products with an extremely broad range of biological activities and pharmacological properties. Polyketide antibiotics, antifungals, cytostatics, anticholesterolemics, antiparasitics, coccidiostatics, animal growth promotants and natural insecticides are in commercial use.

Examples

 * Macrolides
 * Picromycin, the first isolated macrolide (1950)
 * The antibiotics erythromycin A, clarithromycin, and azithromycin
 * The immunosuppressant tacrolimus (FK506)
 * Polyene antibiotics
 * Amphotericin
 * Tetracyclines
 * The tetracycline family of antibiotics
 * Others
 * Discodermolide

Biosynthesis
Polyketides are synthesized by one or more specialized polyketide synthase (PKS) enzymes.