Pyrone polyketides synthesized by a type III polyketide synthase from Drosophyllum lusitanicum

A polyketide synthase cDNA was isolated from callus cultures of Drosophyllum lusitanicum Link. The corresponding recombinant enzyme DluHKS accepted acetyl-CoA as starter substrate and carried out sequential decarboxylative condensations with a malonyl-CoA extender unit. The main product was identified as the hexaketide 6-(2',4'-dihydroxy-6'-methylphenyl)-4-hydroxy-2-pyrone. In addition, α-pyrones derived from three to five acetate units were detected.