Identification of fusaricidins from the antifungal microbial strain Paenibacillus sp. MS2379 using ultra-high performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry

Authors: QIU, SHI - University Of Mississippi; AVULA, BHARATHI - University Of Mississippi; GUAN, SHAOHUA - Agricen Sciences; RAVU, RANGA RAO - University Of Mississippi; WANG, MEI - University Of Mississippi; ZHAO, JIANPING - University Of Mississippi; KHAN, IKHLAS - University Of Mississippi; HINCHEE, MAUD - Agricen Sciences; LI, XING-CONG - University Of Mississippi

Submitted to: Journal of Chromatography A
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/4/2018
Publication Date: 12/5/2018
Citation: Qiu, S., Avula, B., Guan, S., Ravu, R., Wang, M., Zhao, J., Khan, I.A., Hinchee, M., Li, X. 2018. Identification of fusaricidins from the antifungal microbial strain Paenibacillus sp. MS2379 using ultra-high performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry. Journal of Chromatography A. 1586:91-100. https://doi.org/10.1016/j.chroma.2018.12.007.
DOI: https://doi.org/10.1016/j.chroma.2018.12.007

Interpretive Summary: Paenibacillus sp. MS2379 is a highly efficient microbial strain producing fusaricidins, a class of lipopeptides that have demonstrated strong antifungal activities against a broad array of fungal pathogens. An integrated approach combining chromatographic fractionation, Ultra-High Performance Liquid Chromatography Quadrupole Time-of-Flight Mass Spectrometry (UHPLC-QToF-MS) analysis, and Nuclear Magentic Resonance (NMR) spectroscopic interpretation was employed to characterize antifungal metabolites produced by this microbial strain, resulting in the identification of 48 fusaricidins including 30 cyclic and 18 open-chain species. In this regard, UHPLC-QToF-MS played a vital role in determining structures of 28 new fusaricidins through peptide fragment analysis. The structural determination of the new fusaricidins by the high-resolution mass spectrometry was validated by follow-up isolation and NMR spectroscopic analysis of representative compounds. It is worth noting that novel fusaricidins with amino acid residues of serine and y-aminobutyric acid were identified, which is of great biosynthetic significance for this biologically important class of compounds. This study has demonstrated a powerful approach for microbial metabolite profiling, and the structural diversity of the identified fusaricidins makes this microbial strain unique as a potential biocontrol agent.

Technical Abstract: Paenibacillus sp. MS2379 is a highly efficient microbial strain producing fusaricidins, a class of lipopeptides that have demonstrated strong antifungal activities against a broad array of fungal pathogens. An integrated approach combining chromatographic fractionation, Ultra-High Performance Liquid Chromatography Quadrupole Time-of-Flight Mass Spectrometry (UHPLC-QToF-MS) analysis, and Nuclear Magnetic Resonance (NMR) spectroscopic interpretation was employed to characterize antifungal metabolites produced by this microbial strain, resulting in the identification of 48 fusaricidins including 30 cyclic and 18 open-chain species. In this regard, UHPLC-QToF-MS played a vital role in determining structures of 28 new fusaricidins through peptide fragment analysis. The structural determination of the new fusaricidins by the high-resolution mass spectrometry was validated by follow-up isolation and NMR spectroscopic analysis of representative compounds. It is worth noting that novel fusaricidins with amino acid residues of serine and y-aminobutyric acid were identified, which is of great biosynthetic significance for this biologically important class of compounds. The present study again illustrates the power of UHPLC-QToF-MS for structural identification of lipopeptides, and the structural diversity of the identified fusaricidins makes this microbial strain unique as a potential biocontrol agent.