Genome mining of Paraneptunicella aestuarii NBU2194 resulted in the identification of a family of 17-membered macrolides, neptunizhulides A–F. Their structures were elucidated by comprehensive spectroscopic data analysis. Stereochemical assignments of the neptunizhulides were determined by J-based configuration analysis, ROESY NMR, Mosher’s ester derivatization, and bioinformatic predictions. Bioinformatic analysis and a 15N-serine labeling experiment resulted in the identification of a putative trans-acyltransferase polyketide synthase (trans-AT PKS) biosynthetic gene cluster, and a biosynthetic pathway is proposed.

Genome mining of Paraneptunicella aestuarii NBU2194 resulted in the identification of a family of 17-membered macrolides, neptunizhulides A–F. Their structures were elucidated by comprehensive spectroscopic data analysis. Stereochemical assignments of the neptunizhulides were determined by J-based configuration analysis, ROESY NMR, Mosher’s ester derivatization, and bioinformatic predictions. Bioinformatic analysis and a 15N-serine labeling experiment resulted in the identification of a putative trans-acyltransferase polyketide synthase (trans-AT PKS) biosynthetic gene cluster, and a biosynthetic pathway is proposed.