Biosynthesis of brevinic acid from lawsone.

The menaquinone-pathway (men) is widespread in bacteria and key to the biosynthesis of intriguing small molecules such as the essential vitamin menaquinone and the natural dye lawsone. The violet molecule brevinic acid is another proposed product of men, but its direct biosynthetic precursor has remained doubtful. In this study, we isolated brevinic acid from and confirmed its non-enzymatic formation from lawsone and homocysteine involving an intermediate acetylation or phosphorylation step.

Product Selectivity in Baeyer-Villiger Monooxygenase-Catalyzed Bacterial Alkaloid Core Structure Maturation.

Baeyer-Villiger monooxygenases (BVMOs) play crucial roles in the core-structure modification of natural products. They catalyze lactone formation by selective oxygen insertion into a carbon-carbon bond adjacent to a carbonyl group (Baeyer-Villiger oxidation, BVO). The homologous bacterial BVMOs, BraC and PxaB, thereby process bicyclic dihydroindolizinone substrates originating from a bimodular nonribosomal peptide synthetase (BraB or PxaA).