Open AccessGalangin expresses bactericidal activity against multiple‐resistant bacteria: MRSA, Enterococcus spp. and Pseudomonas aeruginosa
Author(s) -
Pepeljnjak Stjepan,
Kosalec Ivan
Publication year - 2004
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1016/j.femsle.2004.09.018
Subject(s) - galangin , microbiology and biotechnology , antimicrobial , minimum inhibitory concentration , propolis , staphylococcus aureus , pseudomonas aeruginosa , minimum bactericidal concentration , chemistry , enterococcus , bacteria , gram negative bacteria , flavonoid , biology , food science , escherichia coli , antibiotics , biochemistry , antioxidant , kaempferol , genetics , gene
The antimicrobial activity of three propolis ethanol extracts (EEP) was examined for various Gram‐negative and Gram‐positive bacterial species, including multiple‐resistant Staphylococcus aureus , Enterococcus spp. and Pseudomonas aeruginosa strains. EEP had a good bactericidal activity against Gram‐positive species, and all multiple‐resistant bacterial strains tested were sensitive to EEP. Minimal inhibitory concentrations (MICs) were lower in samples of higher flavonoid content (from 0.65 to 7.81 mg mL −1 ), indicating the influence of the concentration of some potent bactericidal compound(s) in propolis or synergism among some bactericidal compounds. Antimicrobial‐guided separation of flavonoid aglycones (bioassay in situ on thin‐layer chromatogram) showed that galangin (3,5,7‐trihydroxyflavone) is one compound in EEP with bactericidal activity. Galangin was isolated by preparative chromatography. After determining the quantity present, the MIC against multiple‐resistant bacteria was determined. The MIC of galangin against multiple‐resistant bacterial strains was significantly lower (from 0.16 to 0.44 mg mL −1 , p < 0.05 ) than that of EEP. The bactericidal activity of galangin against P. aeruginosa strains was present at 0.17 ± 0.05 mg mL −1 .