title: Flavanones with potent antibacterial activity against methicillin-resistant Staphylococcus aureus.
abstract: With the therapeutic concept of using the defensive ability of plants against microbial infections, phytoalexin, an antimicrobial phytochemical was studied for its ability to inhibit the growth of methicillin-resistant Staphylococcus aureus (MRSA). Extracts from Sophora exigua (Leguminosae) were fractionated by serial chromatography and the anti-MRSA activity of each fraction was determined by the agar-plate method. Among the active isolates, 5,7,2',6'-tetrahydroxy-6-isoprenyl-8-lavandulyl-4'-methox yflavanone (exiguaflavanone D) completely inhibited the growth of all the MRSA strains examined at the concentration of 1.56-6.25 micrograms mL-1, and 5, 2',6'-trihydroxy-8-lavandulyl-7-methoxy-flavanone (exiguaflavanone B) inhibited at a concentration of 50 micrograms mL-1. This former compound is expected to be a phytotherapeutic agent for MRSA infections as an alternative to conventional antibiotics with unwanted side-effects or the appearance of antibiotic-resistant bacteria.
authors.affiliation: Department of Pharmacognosy, Gifu Pharmaceutical University, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Iinuma
authors.forename: H
authors.initials: H
authors.lastname: Tsuchiya
authors.forename: M
authors.initials: M
authors.lastname: Sato
authors.forename: J
authors.initials: J
authors.lastname: Yokoyama
authors.forename: M
authors.initials: M
authors.lastname: Ohyama
authors.forename: Y
authors.initials: Y
authors.lastname: Ohkawa
authors.forename: T
authors.initials: T
authors.lastname: Tanaka
authors.forename: S
authors.initials: S
authors.lastname: Fujiwara
authors.forename: T
authors.initials: T
authors.lastname: Fujii
mesh_terms: D000900:Anti-Bacterial Agents / Q000302:isolation & purification / Q000494:pharmacology*; D044950:Flavanones; D005419:Flavonoids / Q000302:isolation & purification / Q000494:pharmacology*; D016106:Methicillin Resistance / Q000502:physiology*; D008826:Microbial Sensitivity Tests; D018517:Plant Roots / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D013211:Staphylococcus aureus / Q000187:drug effects*
chemical_list: D000900:Anti-Bacterial Agents; D044950:Flavanones; D005419:Flavonoids; C092613:exiguaflavanone D