The Use of Bioassay-Guided Fractionation in the Isolation and Characterization of Novel Antifungal Drugs from Fungal Sources

As the medical need for novel antifungal compounds continues to rise, chemical ecology is becoming an attractive tool with which to derive antifungal agents. Ecological tools point to a variety of potential sources of fungistatic secondary metabolites. It is speculated that endophytic fungi, in particular, provide for a wealth of potential antifungal compounds. Endphytes appear to protect host plants from natural enemies by producing mycotoxins and antifeedants. The endophytic fungus, KG77, a basidiomycete, was isolated from Selagenilla arenicola (sand spikemoss) from the Archbold Biological Preserve in Florida. The fungus was cultured on Sabouraud Dextrose agar and in Sabouraud Dextrose broth. The secondary metabolites were extracted from the broth with ethyl acetate. The extracts, at an amount of 0.25 mg of product, have shown antifungal activity against Candida albicans C109, C. Albicans 406, C. Albicans wisconsin, C. Albicans A72 and Saccharomyces cerevisiae in disc-diffusion bioassays. Bioassay-guided franctionation has yielded an antifungal compound. Final purification, activity determination and structure elucidation is ongoing