Polyketides are a large group of bioactive secondary metabolites with various biological activities that arise from the diversity in its structures from the precursors of alternating groups like carbonyl and methylene. For this reason, they have a high value in pharmaceutical properties. They are primarily divided into three types: type I, type II and type III polyketides. This pathway focuses on the biosynthesis of type II polyketide products (from the biosynthesis of type II polyketide backbone) which are often based on aromatic molecules produced iteratively by the action of dissociated enzymes in the bacterial species Streptomyces glaucescens. This pathway shows the production of tetracenomycin C and 8-demethyl-tetracenomycin starting from 9,14-decaketides by the action of tcmI, tcmH, tcmN, tcmP, tcmG and tcmO gene proteins. Via a series of reactions using polyketide-synthase, hydroxylase and other enzymes shown in this illustration, the formation of tetracenomycin C occurs. It must be noted that 8-demethyl-tetracenomycin is a derivative of tetracenomycin-C (both shown to be stemming from tetracenomycin-B3) and acts as a teracenomycin having the similar bacterial metabolite role as tetracenomycin-C.

Biosynthesis of Type II Polyketide Products References