Phenolic metabolites of Dalea versicolor that enhance antibiotic activity against model pathogenic bacteria

• Published in: Journal of natural products (Washington, D.C.) Vol. 67; no. 3; pp. 481 - 484
• Main Authors: Belofsky, G, Percivill, D, Lewis, K, Tegos, G.P, Ekart, J
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01-03-2004; Glendale, AZ American Society of Pharmacognosy
• Subjects: Anti-Bacterial Agents - chemistry; Anti-Bacterial Agents - isolation & purification; Anti-Bacterial Agents - pharmacology; Arizona; Bacillus cereus; Bacillus cereus - drug effects; Biological and medical sciences; Dalea versicolor; Fabaceae - chemistry; Flavonoids - chemistry; Flavonoids - isolation & purification; Flavonoids - pharmacology; General pharmacology; Medical sciences; Microbial Sensitivity Tests; Models, Biological; Molecular Structure; Pharmacognosy. Homeopathy. Health food; Pharmacology. Drug treatments; Phenols - chemistry; Phenols - isolation & purification; Phenols - pharmacology; Plants, Medicinal - chemistry; Pterocarpans - chemistry; Spectrometry, Mass, Electrospray Ionization; Staphylococcus aureus; Staphylococcus aureus - drug effects; United States; North America; Arizona; America; Bacillaceae; Flavonoid; Synergism; Medicinal plant; Alkaloid; Polyphenol; Bacillus cereus; Bacillales; Gram positive bacteria; Dicotyledones; Multiple resistance; Angiospermae; Bacteria; Micrococcales; Micrococcaceae; Inhibition; Mechanism of action; Staphylococcus aureus; Pharmacognosy; Whole plant; In vitro; Biological activity; Flavanone derivatives; Antibiotic; Leguminosae; Plant origin; Isolation; Spermatophyta; Antibacterial agent; Structural analysis
• ISSN: 0163-3864; 1520-6025
• DOI: 10.1021/np030409c

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.