Abyssomicins, inhibitors of the para-aminobenzoic acid pathway produced by the marine Verrucosispora strain AB-18-032

A screening method was established to detect inhibitors of the biosynthetic pathways of aromatic amino acids and para-aminobenzoic acid, the precursor of folic acid, using an agar plate diffusion assay modified as an antagonism test. By this screening method, a family of three novel polycyclic polyketides named as abyssomicins was isolated from a marine strain of Verrucosispora. The main component abyssomicin C inhibits the pathway between chorismate and para-aminobenzoic acid and is strongly active against gram-positive bacteria, including multi-resistant clinical isolates of Staphylococcus aureus