A Biosynthetic Classification of Fungal and Streptomycete Fused-Ring Aromatic Polyketides

摘要

Polyketides are one of the largest and most structurally diverse classes of naturally occurring compounds, ranging from simple aromatic metabolites to complex macrocyclic lactones. Fungi and filamentous bacteria, particularly the actinomycetes, are major sources of polycyclic aromatic structures, which include many clinically important antibiotics and other useful metabolites. These fused-ring polyketides are formed by the action of poluyketide synthases (PKSs), which catalyse the assembly, folding and crosslinking of poly-#beta#-ketoacyl intermediates. In view of the taxonomic gulf between the eukaryotic fungi and prokaryotic bacteria, it is not surprising that they are rarely found to produce structurally identical fused-ring metabolites. A review of [~(13)C_2] acetate incorporation data has revealed consistent differences in the reported cyclisation patterns, which require regiospecifically distinct crosslinking of otherwise identical linear polyketides, which has a number of useful ramifications