Isolation and characterization of a new iturinic lipopeptide, mojavensin A produced by a marine-derived bacterium Bacillus mojavensis B0621A

Abstract

Three lipopeptides were isolated by bioactivity-guided fractionation from the fermentation broth of Bacillus mojavensis B0621A. A new iturinic lipopeptide, named mojavensin A (1), was tentatively characterized by 1D, 2D NMR and MS spectroscopy, Marfeys method containing a novel peptide backbone of Asn1, D-Tyr2, D-Asn3, L-Gln4, L-Pro5, D-Asn6, L-Asn7 and an anteiso-type of the saturated Β-fatty acid side chain. Compound 2 and 3 were tentatively identified as iso-C16 fengycin B and anteiso-C17 fengycin B, respectively. These lipopeptides displayed dose-dependent antifungal activity against a broad spectra of phytopathogens and were weakly antagonistic to Staphylococcus aureus. Moreover, they all revealed cytotoxic activities against the human leukemia (HL-60) cell line. Mojavensin A, iso-C16 fengycin B, and anteiso-C17 fengycin B inhibited the growth of HL-60 with IC50 of 100, 100 and 1.6 M, respectively. © 2012 Japan Antibiotics Research Association All rights reserved.