African Journal of
Biochemistry Research

  • Abbreviation: Afr. J. Biochem. Res.
  • Language: English
  • ISSN: 1996-0778
  • DOI: 10.5897/AJBR
  • Start Year: 2007
  • Published Articles: 408

Full Length Research Paper

Kinetic study of different flavonoids as inhibitors of beta-lactamase enzyme

BOUSSOUALIM, Naoual1, MEZIANE-CHERIF, Djalal2 and BAGHIANI, Abderrahmane1*
1Laboratory of Applied Biochemistry, Department Biochemistry, Faculty of Natural Sciences and Life, University Ferhat Abbas-Setif, Algeria. 2Institut Pasteur, Plateforme 6, CNRS URA 2185, 25 rue du Dr Roux, 75724 Paris Cedex 15, France.
Email: [email protected]

  •  Accepted: 15 August 2011
  •  Published: 30 September 2011


The phenotypic study of the clinical strain Escherichia coli K18 showed that it is resistant to penicillin and amoxicillin-clavulanate, but susceptible to the combination of piperacillin-tazobactam and the cephalosporins 3rd generation and meropenem. The isolated β-lactamase, using ion-exchange chromatography on resin Mono-Q, gave a yield of 56%, a purification factor equal to 5.9, a molecular weight of approximately 24 KDa and a pI of 5.2. Clavulanic acid, tazobactam and sulbactam were competitive inhibitors with KI and IC50 far beyond the values of those of TEM-1. 13 molecules of different flavonoÏŠds, three phenolic acids (cafeic acid, ellagic acid and gallic acid) are tested for their ability to inhibit β-lactamase. The type of inhibition and KIare determined and the relationship between the structure and activity was established. The results showed that fisetin, flavone, quercetin, catechin and gossypin are non-competitive inhibitors. Myricetin, quercitrin, naringenin, morin, kaempferol and rutin are non-competitive inhibitors. The KI of the most flavonoÏŠds tested are above 100 μM, which are 200 folds less effective than clavulanic acid (KI = 0.5 µM). We can conclude that the position of OH in the structures of molecules has a major influence.


Key words: β-lactamase, Escherichia coli, β-lactam, clavulanic acid, flavonoids, phenolic acids.