title: Antibacterial secondary metabolites from an endophytic fungus, Fusarium solani JK10.
abstract: Extensive chemical investigation of the endophytic fungus, Fusarium solani JK10, harbored in the root of the Ghanaian medicinal plant Chlorophora regia, using the OSMAC (One Strain Many Compounds) approach resulted in the isolation of seven new 7-desmethyl fusarin C derivatives (1-7), together with five known compounds (8-12). The structures of the new compounds were elucidated by analysis of their spectroscopic data including 1D, 2D NMR, HRESI-MSnand IR data. The relative configuration of compounds 1/2 was deduced by comparison of their experimental electronic circular dichroism (ECD) and optical rotation data with those reported in literature. The absolute configuration of solaniol (10), a known compound with undefined absolute stereochemistry, was established for the first time by X-ray diffraction analysis of a single-crystal structure using Cu-Kα radiation. The antibacterial activities of the crude fungal extract and the compounds isolated from the fungus were evaluated against some clinically important bacterial strains such as Staphylococcus aureus and Bacillus subtilis, as well as an environmental strain of Escherichia coli and the soil bacterium Acinetobacter sp. BD4. Compounds 3/4 and 6 exhibited antibacterial efficacies against the soil bacterium Acinetobacter sp., comparable to the reference standard streptomycin. All the tested compounds (1-9) demonstrated antibacterial activity against the environmental strain of E. coli, whereas no antibacterial activity was observed against S. aureus and B. subtilis. The antibacterial activity of the isolated compounds typically against E. coli and Acinetobacter sp. provides further insight into the possible involvement of root-borne endophytes in chemical defense of their host plants in selected ecological niches.
authors.affiliation: Department of Pharmaceutical Chemistry, Faculty of Pharmacy and Pharmaceutical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana; Institute of Environmental Research (INFU), Department of Chemistry and Chemical Biology, Chair of Environmental Chemistry and Analytical Chemistry, TU Dortmund, Otto-Hahn-Straße 6, 44221 Dortmund, Germany.
authors.forename: James Oppong
authors.initials: JO
authors.lastname: Kyekyeku
authors.affiliation: Institute of Environmental Research (INFU), Department of Chemistry and Chemical Biology, Chair of Environmental Chemistry and Analytical Chemistry, TU Dortmund, Otto-Hahn-Straße 6, 44221 Dortmund, Germany. Electronic address: souvik.kusari@tu-dortmund.de.
authors.forename: Souvik
authors.initials: S
authors.lastname: Kusari
authors.affiliation: Department of Pharmaceutical Chemistry, Faculty of Pharmacy and Pharmaceutical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
authors.forename: Reimmel Kwame
authors.initials: RK
authors.lastname: Adosraku
authors.affiliation: Institute of Environmental Research (INFU), Department of Chemistry and Chemical Biology, Chair of Environmental Chemistry and Analytical Chemistry, TU Dortmund, Otto-Hahn-Straße 6, 44221 Dortmund, Germany.
authors.forename: Anke
authors.initials: A
authors.lastname: Bullach
authors.affiliation: Inorganic Chemistry, Department of Chemistry and Chemical Biology, TU Dortmund, Otto-Hahn-Straße 6, D-44221 Dortmund, Germany.
authors.forename: Christopher
authors.initials: C
authors.lastname: Golz
authors.affiliation: Inorganic Chemistry, Department of Chemistry and Chemical Biology, TU Dortmund, Otto-Hahn-Straße 6, D-44221 Dortmund, Germany.
authors.forename: Carsten
authors.initials: C
authors.lastname: Strohmann
authors.affiliation: Institute of Environmental Research (INFU), Department of Chemistry and Chemical Biology, Chair of Environmental Chemistry and Analytical Chemistry, TU Dortmund, Otto-Hahn-Straße 6, 44221 Dortmund, Germany. Electronic address: michael.spiteller@tu-dortmund.de.
authors.forename: Michael
authors.initials: M
authors.lastname: Spiteller
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000302:isolation & purification; D001419:Bacteria / Q000187:drug effects; D060026:Endophytes / Q000737:chemistry*; D005670:Fusarium / Q000737:chemistry*; D005869:Ghana; D015394:Molecular Structure; D018517:Plant Roots / Q000382:microbiology; D010946:Plants, Medicinal / Q000382:microbiology
chemical_list: D000900:Anti-Bacterial Agents
keywords: 7–desmethyl fusarin C derivatives; Antibacterial; Chlorophora regia; Fusarium solani; Solaniol; X–ray crystallography