A New Mechanism for Benzopyrone Formation in Aromatic Polyketide Biosynthesis

摘要

This work demonstrated that, in addition to amide-and pyridone-containing compounds, a primary amide moiety can also serve as an electrophilic center when positioned favorably, readily yielding pyrone-containing polyketides. Benzopyrones are widely present in natural products and are typically formed through esterification of carboxylic acids, intramolecular hydrolysis of enzyme-attached thioesters, or through recently reported oxidative rearrangement. The observed involvement of the amide moiety in pyrone formation may be the mechanism by which pyrones are formed in other aromatic polyketides, including those in the rubromycin family. Interestingly, OxyD-like amidotransferase ho-mologues are present in these gene clusters, while no nitrogen atoms were present in the reported polyketide structures.