Purification, primary structures, and antibacterial activities of ␤-defensins, a new family of antimicrobial peptides from bovine neutrophils.

Three novel metabolites (1, 5 and 10) were isolated from a 25-L fermentation broth of Actinomyces sp. JN411010 together with 11 related compounds. Their structures were determined on the basis of 1D and 2D NMR, as well as HR-ESI-MS spectroscopic data analyses. Compounds 1-2, 5-8 and 10 displayed moderate antimicrobial activities against Gram-positive and Gram-negative bacteria. Biosynthetic pathway of 5 and 10 was proposed to be catalysed by polyketide and non-ribosomal peptide gene clusters, respectively.