Flavonoids from Artemisia rupestris and their synergistic antibacterial effects on drug-resistant Staphylococcus aureus

Jiang-Er Lan, Xiao-Jin Li, Xiao-Feng Zhu, Zhong-Lin Sun, Jian-Ming He, Mire Zloh, Simon Gibbons, Qing Mu

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30 Citations (Scopus)


This study seeks to discover flavonoids from a traditional Chinese herb, Artemisia rupestris L., with synergistic antibacterial effects against multidrug-resistant Staphylococcus aureus. Five flavonoids, artemetin (1), chrysosplenetin (2), pachypodol (3), penduletin (4) and chrysoeriol (5) were obtained by various column chromatographic methods. Their chemical structures were determined on the basis of comprehensive spectroscopic analysis and comparison with literature data. Three of the compounds (2, 4 and 5) exhibited synergistic activity when combined with norfloxacin against SA1199B, an effluxing fluoroquinolone-resistant strain. The fractional inhibitory concentration indices (FICIs) of 2, 4 and 5 in combination with norfloxacin were 0.375, 0.079 and 0.266 respectively, suggesting synergy. Compound 5 also showed synergistic effects against EMRSA-15 and EMRSA-16 when combined with ciprofloxacin and oxacillin exhibiting FICIs of 0.024 and 0.375 respectively. Real time ethidium bromide (EtBr) efflux assay, qRT-PCR and molecular docking were employed to explore the mechanisms of the synergistic effects.

Original languageEnglish
Pages (from-to)1881-1886
Number of pages6
JournalNatural Product Research
Issue number11
Early online date13 Jul 2019
Publication statusPublished - 2021


  • Artemisia rupestrisL
  • efflux inhibitor
  • flavonoids
  • molecular docking
  • multidrug-resistant Staphylococcus aureus
  • synergism

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