|Shim, Sang hee|
Submitted to: Journal of Natural Products
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/4/2011
Publication Date: 1/19/2011
Citation: Shim, S., Baltrusaitis, J., Gloer, J.B., Wicklow, D.T. 2011. Phomalevones A-C: Dimeric and pseudodimeric polyketides from a fungicolous Hawaiian isolate of Phoma sp. (Cucurbitariaceae). Journal of Natural Products. 74(3):395-401. Interpretive Summary: Fungicide resistance in agriculture and antibiotic resistance in medicine necessitates the need to find new active agents. Fungi that parasitize and kill other fungi offer a potential source of novel antifungal compounds. A previously undescribed species of Phoma sp. NRRL 39060, encountered as a colonist and potential parasite of a wood decay fungus collected in a Montane Dry Forest, Kailua-Kona, Hawaii, was examined for its ability to produce antifungal agents and other bioactive metabolites. Phomalevones are reported as new metabolites exhibiting antifungal activity against pathogens Aspergillus flavus, Candida albicans and Fusarium verticillioides as well as antibacterial activity against Bacillus subtilis, Escherichia coli and Staphylococcus aureus. The research has discovered novel metabolites with antifungal and antibacterial effects, information that can serve to guide the synthesis of antibiotics and fungicides important to agriculture with additional considerable potential for discovery of chemistry with medically relevant biological effects.
Technical Abstract: Phomalevones A-C (1-3), three new compounds with bis-dihydroxanthone and bis-benzophenone systems, were isolated from cultures of a Hawaiian isolate of Phoma sp. (MYC-1734 =NRRL 39060; Cucurbitariaceae). The structures of 1-3 were determined by analysis of NMR and MS data. The absolute configurations of the sp3 stereocenters in the monomeric unit of 1 were assigned by application of Mosher’s method, and overall absolute configurations were proposed on the basis of ECD data using both computational methods and comparisons with literature data for model compounds. All three compounds showed antibacterial activity, and compounds 2 and 3 also exhibited antifungal effects.