Genome mining and chemical characterization of a new cyclic lipopeptide associated with MDN-0066 from Pseudomonas moraviensis HN2 cultured in a valine-rich medium

A new cyclic lipopeptide (CLP) MDN-0066-beta (1) and MDN-0066 (2) were isolated and characterized from the bacterial cultures of P. moraviensis HN2 in this study. The CLPs were purified by solid-phase extraction (SPE) and reversed-phase high performance liquid chromatography (RP-HPLC). Moreover, chemical structures of two CLPs were characterized by genome mining and analysis, nuclear magnetic resonance (NMR), high-resolution mass spectrometry (HR-MS), Marfey's method and (C-H)alpha NMR fingerprint matching approach. MDN-0066 (2) has an amino acid sequence of l-Leu(1), d-Glu(2), d-allo-Thr(3), d-Leu(4), d-Leu(5), d-Ser(6), l-Leu(7), l-Ile(8) linked to a saturated C-10 beta-hydroxyl fatty acid moiety (R-configuration for 3-OH). The new CLP MDN-0066-beta (1) differs MDN-0066 (2) in the 8th position of l-valine in its peptide moiety, this variation in structure could be attributed to the supplement of l-valine in the cultural medium during liquid fermentation. Further antimicrobial tests showed that the two CLPs display moderate antagonistic activity against Staphylococcus aureus and Escherichia coli.

Automated summary

A new cyclic lipopeptide (CLP) MDN-0066-beta (1) and MDN-0066 (2) were isolated and characterized from the bacterial cultures of P. moraviensis HN2 in this study. The chemical structures of these two CLPs were determined using genome mining and analysis, NMR, HR-MS, Marfey's method, and C-H NMR fingerprint matching approach. MDN-0066-beta (1) and MDN-0066 (2) showed moderate antagonistic activity against Staphylococcus aureus and Escherichia coli.