title: Structures of two new flavonoids and effects of licorice phenolics on vancomycin-resistant Enterococcus species.
abstract: Since our previous study revealed that several licorice phenolics have antibacterial effects on methicillin-resistant Staphylococcus aureus (MRSA), and suppressive effects on the oxacillin resistance of MRSA, we further investigated effectiveness of licorice constituents on vancomycin-resistant Enterococcus (VRE) bacteria, and purified 32 phenolic compounds. Two flavonoids among them were characterized structurally, and identified their structures as demethylglycyrol (31) and 5,7-di-O-methylluteone (32), respectively. Examination of antibacterial effects of licorice phenolics showed that 3-arylcoumarins such as licoarylcoumarin (9) and glycycoumarin (26), and 2-arylcoumarones such as gancaonin I (17), have moderate to potent antibacterial effects on the VRE strains used in this study.
authors.affiliation: Department of Natural Product Chemistry, Okayama University, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Tsushima-naka, Kita-ku, Okayama 700-8530, Japan. eerdun3@163.com.
authors.lastname: Eerdunbayaer
authors.affiliation: Department of Natural Product Chemistry, Okayama University, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Tsushima-naka, Kita-ku, Okayama 700-8530, Japan. m_a_orabi@yahoo.com.
authors.forename: Mohamed A A
authors.initials: MA
authors.lastname: Orabi
authors.affiliation: Department of Natural Product Chemistry, Okayama University, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Tsushima-naka, Kita-ku, Okayama 700-8530, Japan. ph20101@s.okayama-u.ac.jp.
authors.forename: Hiroe
authors.initials: H
authors.lastname: Aoyama
authors.affiliation: Drug Discovery Technology Center, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Tsushima-naka, Kita-ku, Okayama 700-8530, Japan. tkuroda@cc.okayama-u.ac.jp.
authors.forename: Teruo
authors.initials: T
authors.lastname: Kuroda
authors.affiliation: Department of Natural Product Chemistry, Okayama University, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Tsushima-naka, Kita-ku, Okayama 700-8530, Japan. hatano@pharm.okayama-u.ac.jp.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Hatano
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D003374:Coumarins / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D016983:Enterococcus / Q000187:drug effects* / Q000254:growth & development; D005419:Flavonoids / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D006035:Glycyrrhiza / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D010636:Phenols / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D010936:Plant Extracts / Q000737:chemistry; D014640:Vancomycin / Q000494:pharmacology; D020713:Vancomycin Resistance / Q000502:physiology
chemical_list: D000900:Anti-Bacterial Agents; D003374:Coumarins; D005419:Flavonoids; D010636:Phenols; D010936:Plant Extracts; D014640:Vancomycin