Phenolic constituents of licorice. VIII. Structures of glicophenone and glicoisoflavanone, and effects of licorice phenolics on methicillin-resistant Staphylococcus aureus

Tsutomu Hatano, Yasushi Shintani, Yasuhiro Aga, Sumiko Shiota, Tomofusa Tsuchiya, Takashi Yoshida

Research output: Contribution to journalArticle

114 Citations (Scopus)

Abstract

Two new phenolic compounds, glicophenone (1) and glicoisoflavanone (2), were isolated from commercial licorice, and their structures were elucidated on the basis of spectroscopic data. Antibacterial assays of licorice phenolics for Staphylococcus aureus, including four strains of methicillin-resistant S. aureus (MRSA), and also for Escherichia coli K12 and Pseudomonas aeruginosa PAO1, were then examined. Two compounds among them, 8-(γ,γ-dimethylallyl)-wighteone (21) and 3'-(γ,γ-dimethylallyl)-kievitone (28), showed remarkable antibacterial effects [minimum inhibitory concentrations (MICs), 8 μg/ml] on the MRSA strains and methicillin-sensitive S. aureus. Licochalcone A (14), gancaonin G (20), isoangustone A (24), glyasperins C (30) and D (31), glabridin, (32), licoricidin (33), glycycoumarin (34) and licocoumarone (40) showed antibacterial effects on the MRSA strains with MIC values of 16 μg/ml. Effects on the β-lactam resistance of the MRSA strains were also examined, and licoricidin (33) noticeably decreased the resistance of the MRSA strains against oxacillin, as shown by the reduction in the MICs of oxacillin (lower than 1/128 - 1/1000 in the presence of 8 μg/ml of 33, and 1/8 - 1/32 in the presence of 4 μg/ml of 33). Mechanistic study suggested that 33 does not inhibit the formation of penicillin-binding protein 2' (PBP2'), but affects the enzymatic function of PBP2'.

Original languageEnglish
Pages (from-to)1286-1292
Number of pages7
JournalChemical and Pharmaceutical Bulletin
Volume48
Issue number9
DOIs
Publication statusPublished - Jan 1 2000

Keywords

  • Glicoisoflavanone
  • Glicophenone
  • Licorice
  • Licoricidin
  • Methicillin-resistant Staphylococcus aureus
  • Oxacillin

ASJC Scopus subject areas

  • Chemistry(all)
  • Drug Discovery

Fingerprint Dive into the research topics of 'Phenolic constituents of licorice. VIII. Structures of glicophenone and glicoisoflavanone, and effects of licorice phenolics on methicillin-resistant Staphylococcus aureus'. Together they form a unique fingerprint.

  • Cite this