Polyketides

(noun)

Polyketides are secondary metabolites from bacteria, fungi, plants, and animals. Polyketides are usually biosynthesized through the decarboxylative condensation of malonyl-CoA derived extender units in a similar process to fatty acid synthesis (a Claisen condensation).

Related Terms

Examples of Polyketides in the following topics:

  • Polyketide Antibiotics

    • Polyketides are secondary metabolites produced from bacteria, fungi, plants, and animals.
    • Polyketides are secondary metabolites produced from bacteria, fungi, plants, and animals.
    • The polyketide chains produced by a minimal polyketide synthase are often further derivitized and modified into bioactive natural products.
    • Polyketides are synthesized by one or more specialized and highly complex polyketide synthase (PKS) enzymes.
    • Describe the characteristics associated with polyketides, including:  type I, II and III polyketides

  • Nonribosomal Peptide Antibiotics

    • The biosynthesis of nonribosomal peptides shares characteristics with the polyketide and fatty acid biosynthesis.
    • Due to these structural and mechanistic similarities, some nonribosomal peptide synthetases contain polyketide synthase modules for the insertion of acetate or propionate-derived subunits into the peptide chain.

  • Damage to Proteins and Nucleic Acids

    • Tetracycline is a broad-spectrum polyketide antibiotic produced by the Streptomyces genus of Actinobacteria, indicated for use against many bacterial infections.

  • Condensation Reactions

    • Many biological transformations, such as polypeptide synthesis, polyketide synthesis, terpene syntheses, phosphorylation, and glycosylations are condensations.

  • Fungi

    • Many fungal species produce bioactive compounds called mycotoxins, such as alkaloids and polyketides that are toxic to animals including humans, contributing to pathogenecity and disease.

  • Biosynthetic Mechanisms

  • Lipid Biosynthesis

    • Using this approach, lipids may be divided into eight categories: fatty acids, glycerolipids, glycerophospholipids, sphingolipids, saccharolipids, and polyketides (derived from condensation of ketoacyl subunits); and sterol lipids and prenol lipids (derived from condensation of isoprene subunits ).