Iterative polyketide synthase; part of the gene cluster that mediates the biosynthesis of asperfuranone, a probable antitumor agent (PubMed:19199437). The polyketide synthase afoG is responsible for producing the 3,5-dimethyloctadienone moiety from acetyl-CoA, three malonyl-CoA, and two S-adenosyl methionines (SAM) (PubMed:19199437). The 3,5-dimethyloctadienone moiety is then loaded onto the SAT domain of afoE and extended with four malonyl-CoA and one SAM, which leads to the formation of 2,4-dihydroxy-6-(5,7-dimethyl-2-oxo-trans-3-trans-5-nonadienyl)-3-methylbenzaldehyde (compound 2) after reductive release and aldol condensation (PubMed:19199437, PubMed:22510154). AfoD is the next enzyme in the biosynthesis sequence and hydroxylates the side chain at the benzylic position of compound 2 (PubMed:19199437). After benzylic hydroxylation, a furan ring is formed after five-member ring hemiacetal formation and water elimination (PubMed:19199437). AfoF and afoC are proposed to oxidize the R-diketone proton and to reduce the unconjugated carbonyl group, respectively, to generate asperfuranone (PubMed:19199437). Since no intermediates could be isolated from afoF and afoC deletants, the sequence of these two enzymes is not fully understood (PubMed:19199437). Moreover, since afoC deletant still produces a small amount of asperfuranone, other endogenous oxidoreductases might catalyze the same reaction with much less efficiency (PubMed:19199437). (3E,5E,7S)-5,7-dimethyl-2-oxonona-3,5-dienyl-[ACP] + AH2 + 3 H(+) + 4 malonyl-CoA + S-adenosyl-L-methionine = 6-[(3E,5E,7S)-5,7-dimethyl-2-oxonona-3,5-dienyl]-2,4-dihydroxy-3-methylbenzaldehyde + A + 4 CO2 + 4 CoA + H2O + holo-[ACP] + S-adenosyl-L-homocysteine Binds 1 phosphopantetheine covalently. Secondary metabolite biosynthesis. Expression is regulated by the asperfuranone cluster transcription factor afoA (PubMed:19199437). Multidomain protein; including an N-terminal starter unit:ACP transacylase (SAT) domain, a beta-ketoacyl synthase (KS) domain, a malonyl-CoA:ACP transacylase (MAT) domain, a product template domain, a acyl carrier protein (ACP) domain, a methyltransferase domain and a reductive NADPH-binding domain that is required for NADPH-dependent product release. Completely abolishes the production of asperfuranone (PubMed:19199437). Asperfuranone provides anti-proliferative activity in human non-small cell lung cancer cells (PubMed:20148857).