title: Heterologous biosynthesis of truncated hexaketides derived from the actinorhodin polyketide synthase.
abstract: Heterologous expression of the actinorhodin polyketide synthase in the recombinant host Streptomyces lividans K4-114 led to the characterization of three new minor polyketides, the novel hexaketides BSM1 and BSM3 and 9'-hydroxyaloesaponarin II, in addition to known anthraquinone and aromatic octaketides. The structures of BSM1 and BSM3 imply that these compounds are derived from a C-5-reduced hexaketide intermediate, suggesting that the timing of the ketoreduction reaction in the actinorhodin biosynthetic pathway may take place during the polyketide elongation process rather than after the completion of the octaketide chain as previously suggested.
authors.affiliation: College of Pharmacy and Department of Chemistry, University of Arizona, Tucson, Arizona 85721, USA.
authors.forename: John A
authors.initials: JA
authors.lastname: Kalaitzis
authors.forename: Bradley S
authors.initials: BS
authors.lastname: Moore
mesh_terms: D000880:Anthraquinones / Q000138:chemical synthesis* / Q000737:chemistry; D005818:Genetic Engineering; D018942:Macrolides / Q000138:chemical synthesis* / Q000378:metabolism*; D015394:Molecular Structure; D009097:Multienzyme Complexes / Q000235:genetics / Q000378:metabolism*; D013302:Streptomyces / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*
chemical_list: C492418:9'-hydroxyaloesaponarin II; D000880:Anthraquinones; D018942:Macrolides; D009097:Multienzyme Complexes