title: Antimicrobial Coumarins from the Oyster Culinary-Medicinal Mushroom, Pleurotus ostreatus (Agaricomycetes), from Kenya.
abstract: Pleurotus ostreatus has been widely used as food because of its nutritional and medicinal properties. These have been attributed to the presence of macronutrients, minerals, vitamins, and amino acids, among other secondary metabolites. There are, however, few reports on the antimicrobial activities of different classes of purified compounds from P. ostreatus. This led to the current study, the objective of which was to chemically characterize the antibiotic activities of P. ostreatus against selected human pathogenic bacteria and endophytic fungi. Chemical structures were determined using spectroscopic methods and by comparison with values of related structures reported in the literature. Pure compounds from P. ostreatus were tested in vitro against pathogenic bacteria (Staphylococcus aureus and Escherichia coli) and endophytic fungi (Pencillium digitatum and Fusarium proliferatum). A new compound, (E)-5,7-dimethoxy-6-(3-methylbuta-1,3-dienyl)-2H-chromen-2-one (5-methoxy-(E)-suberodiene) (compound 2), along with ergosterol (compound 1) and 5,7-dimethoxy-6-(3-methylbut-2-enyl)-2H-chromen-2-one (toddaculin; compound 3), were isolated from the fruiting bodies of P. ostreatus. The growth of S. aureus, F. proliferatum, and P. digitatum colonies was inhibited in media containing compound 2, with minimum inhibitory concentrations closely comparable to those of conventional antibiotics.
authors.affiliation: Department of Pure and Applied Chemistry, Masinde Muliro University of Science and Technology, Kakamega, Kenya.
authors.forename: Lilechi D
authors.initials: LD
authors.lastname: Baraza
authors.affiliation: Department of Pure and Applied Chemistry, Masinde Muliro University of Science and Technology, Kakamega, Kenya.
authors.forename: Wekesa
authors.initials: W
authors.lastname: Neser
authors.affiliation: Department of Biological Sciences, Masinde Muliro University of Science and Technology, Kakamega, Kenya.
authors.forename: Korir Cheruiyot
authors.initials: KC
authors.lastname: Jackson
authors.affiliation: Department of Pure and Applied Chemistry, Masinde Muliro University of Science and Technology, Kakamega, Kenya.
authors.forename: Juma B
authors.initials: JB
authors.lastname: Fredrick
authors.affiliation: Department of Biological Sciences, Masinde Muliro University of Science and Technology, Kakamega, Kenya.
authors.forename: Ochieno
authors.initials: O
authors.lastname: Dennis
authors.affiliation: Department of Pure and Applied Chemistry, Masinde Muliro University of Science and Technology, Kakamega, Kenya.
authors.forename: Kamau R
authors.initials: KR
authors.lastname: Wairimu
authors.affiliation: Department of Biological Sciences, Masinde Muliro University of Science and Technology, Kakamega, Kenya.
authors.forename: Aggrey Osogo
authors.initials: AO
authors.lastname: Keya
authors.affiliation: Universität Potsdam, Institut für Chemie, Potsdam, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Heydenreich
mesh_terms: D000890:Anti-Infective Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D001203:Ascomycota / Q000187:drug effects / Q000254:growth & development; D003374:Coumarins / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development; D048690:Fruiting Bodies, Fungal / Q000737:chemistry*; D005670:Fusarium / Q000187:drug effects / Q000254:growth & development; D007630:Kenya; D008826:Microbial Sensitivity Tests; D010407:Penicillium / Q000187:drug effects / Q000254:growth & development; D020076:Pleurotus / Q000737:chemistry*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development
chemical_list: D000890:Anti-Infective Agents; D003374:Coumarins