title: Synthesis and biological activity of novel pyranopyrones derived from engineered aromatic polyketides.
abstract: The 4-hydroxy-2-pyrone moiety is commonly observed in polyketides generated via biosynthetic engineering of type II polyketide synthases. To explore the synthetic utility of these 2-pyrones, four engineered polyketides (mutactin, SEK4, SEK15, and SEK15b) were isolated from appropriate derivatives of Streptomyces coelicolor CH999. As a test case, we prepared nine novel pyranopyrones through condensation reactions with either citral, 1-cyclohexene-carboxaldehyde, or S-perillaldehyde. Synthetic tricyclic pyranopyrones with simple aromatic substituents are known to possess anticancer properties. We therefore investigated whether pyranopyrone derivatives of aromatic polyketides exhibited bioactivity in a panel of three cancer cell lines. Pyranopyrones generated from SEK4 had activity comparable to that of H10, a pyranopyrone with a 3-pyridyl substituent, whereas other analogues were less active. These results suggest that the diverse library of carbo- and heterocycles available through the genetic engineering of type II polyketide synthases can serve as useful building blocks to generate unique bioactive molecules.
authors.forename: Christian P
authors.initials: CP
authors.lastname: Ridley
authors.forename: Chaitan
authors.initials: C
authors.lastname: Khosla
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000494:pharmacology; D045744:Cell Line, Tumor; D005818:Genetic Engineering; D006801:Humans; D048630:Polyketide Synthases / Q000235:genetics*; D011753:Pyrones / Q000138:chemical synthesis* / Q000494:pharmacology; D013329:Structure-Activity Relationship
chemical_list: D000970:Antineoplastic Agents; D011753:Pyrones; D048630:Polyketide Synthases