| Resumo: |
The bacteriostatic activity of 2,4,2-trihydroxychalcone; 2,4,3-trihydroxychalcone and 2,4,4-trihydroxychalcone, prepared by condensation of 2,4-dihydroxyacetophenone and benzaldehyde substituted, against Staphylococcus aureus ATCC 25923 was assayed by agar plate method. The three compounds presented important inhibition halos. In order to elucidate structure-activity relationships, the minimal inhibitory concentrations against S. aureus were determined by the broth dilution method and the results obtained were compared to that of 2',4'-dihydroxychalcone. The sequence observed was: MIC 2,4,3-(OH)3 > MIC 2,4-(OH)2 > MIC 2,4,4-(OH)3 > > MIC 2,4,2-(OH)3. These results showed that the introduction of an electron donating group (-OH) in the aromatic B-ring causes an increase in bioactivity, and that the intensity of action depends on the position of the OH substitute.
|
