title: Phenolic metabolites of Dalea versicolor that enhance antibiotic activity against model pathogenic bacteria.
abstract: A new flavonoid (1) was isolated from organic extracts of Dalea versicolor, along with six known phenolic compounds (2-7). The structures of the seven compounds were determined by NMR and HRMS methods. These compounds were evaluated for direct activity against a variety of organisms in vitro, including the Gram-positive bacteria Staphylococcus aureus and Bacillus cereus. In addition, the compounds were evaluated for their ability to potentiate the activity of known antimicrobials through inhibition of multidrug-resistance (MDR) pumps. Compounds 1, 2, 4, and 7 exhibited direct or synergistic activity toward the human pathogen S. aureus and the opportunistic pathogen B. cereus. Compounds 4 and 7 were also found to potentiate the activity of berberine and of prescribed antibiotics, with 4 demonstrating a mode of action consistent with inhibition of the NorA MDR efflux pump in S. aureus.
authors.affiliation: Department of Chemistry and Biochemistry, The University of Tulsa, Tulsa, Oklahoma 74101, USA.
authors.forename: Gil
authors.initials: G
authors.lastname: Belofsky
authors.forename: Diamond
authors.initials: D
authors.lastname: Percivill
authors.forename: Kim
authors.initials: K
authors.lastname: Lewis
authors.forename: George P
authors.initials: GP
authors.lastname: Tegos
authors.forename: Julie
authors.initials: J
authors.lastname: Ekart
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D001130:Arizona; D001409:Bacillus cereus / Q000187:drug effects; D007887:Fabaceae / Q000737:chemistry*; D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D008954:Models, Biological; D015394:Molecular Structure; D010636:Phenols / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D010946:Plants, Medicinal / Q000737:chemistry*; D036343:Pterocarpans / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization; D013211:Staphylococcus aureus / Q000187:drug effects; D000094162:Phytoalexins
chemical_list: D000900:Anti-Bacterial Agents; D005419:Flavonoids; D010636:Phenols; D036343:Pterocarpans; C484933:dalversinol A; C047353:medicarpin; D000094162:Phytoalexins