Abstract

ALVAREZ, María De Los Angeles; ZARELLI, Valeria E. P.; PAPPANO, Nora B.  and  DEBATTISTA, Nora B.. Bacteriostatic action of synthetic polyhydroxylated chalcones against Escherichia coli. Biocell [online]. 2004, vol.28, n.1, pp.31-34. ISSN 0327-9545.

In previous work the bacteriostatic action of trihydroxylated chalcones against Staphylococcus aureus ATCC 25 923 was investigated. In this work the action of 2´,4´,2-(OH)3-chalcone, 2´,4´,3-(OH)3- chalcone and 2´,4´,4-(OH)3 -chalcone against Escherichia coli ATCC 25 922 was evaluated. Growth kinetic curves of E.coli were made in nutritive broth added with increasing drug concentrations. The specific growth rates of the microorganisms were calculated by a kinetic turbidimetric method, which was previously probed and the minimal inhibitory concentrations (MIC´s) were evaluated by a mechanism of action proposed. The MICs of 2´,4´,3-(OH)3-chalcone and 2´,4´,2-(OH)3-chalcone were 46 mg/ml and 122 mg/ml, respectively. The 2´,4´,4-(OH)3-chalcone was inactive. The MIC value of 2´, 4´, 3-(OH) 3-chalcone (46 mg/ml), more active than 2´, 3-(OH) 2-chalcone (72.2 mg/ml) may be due to the introduction of an electron donating group (-OH) at position 4´ in the aromatic A- ring, which activates the region that includes the 2´-hydroxyl neighbur group and the a,b- unsaturated carbonyl group.

Keywords : Chalcones; Bacteriostatic Activity; Hydroxylation.

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