Isolation of novel naphthoquinones from fungal strain MSX53507, Cladorrhinum sp.

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Jacklyn M. Gallagher (Creator)
The University of North Carolina at Greensboro (UNCG )
Web Site:
Nicholas Oberlies

Abstract: This study was conducted as part of an ongoing collaborative project to investigate the chemical diversity of fungi in search of new anticancer drug leads. Fungi have shown to be prolific producers of dynamic secondary metabolites, which exhibit a vast array of physiological activities. In particular, naphthoquinones and their derivatives have long been of interest to medicinal and natural product researchers due to their diverse biological activities such as cytotoxicity, antibacterial, antifungal, antiparasitic, and insecticidal. An established dereplication protocol for screening and prioritization of fungal samples for cytotoxicity, indicated that the biological activity of MSX53507 was not attributable to any compounds (new or known) previously isolated and identified in our research laboratory. Bioactivity-guided fractionation, the primary methodology in our laboratory in which results can take weeks, was conducted solely for screening and prioritization of fractions for further investigation. Preliminary work yielded compounds which encompass an easily identifiable feature in 1H-NMR spectroscopy that is characteristic to this class of compounds. Employing a proton-NMR guided fractionation methodology for purification of biologically active fractions, led to the isolation of four new naphthoquinone analogues (1, 3, and 6-7), two known compounds (4-5) and a naphthoquinone previously misidentified in the literature (2). Naphthoquinone’s broad spectrum of biological activity led us to test compounds 2, 5, and 6 against Staphylococcus aureus (ATCC 35667) and a clinically relevant methicillin-resistant S. aureus strain (MRSA) where 5 was the most active with minimum inhibitory concentrations (MICs) of 2.3 µg/mL and 16.0 µg/mL, respectively. [This abstract has been edited to remove characters that will not display in this system. Please see the PDF for the full abstract.]

Additional Information

Language: English
Date: 2019
Antibacterial, Cladorrhinum, Cytotoxic, Fungi, Naphthoquinones, Natural Products
Antibacterial agents
Fungal metabolites
Natural products

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