SciELO - Scientific Electronic Library Online

 
vol.17 issue8EPR and semi-empirical studies as tools to assign the geometric structures of FeIII isomer models for transferrinsA novel binuclear ruthenium complex: spectroscopic and electrochemical characterization, and formation of Langmuir and Langmuir-Blodgett films author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Journal of the Brazilian Chemical Society

Print version ISSN 0103-5053

Abstract

GUERRA, Wendell et al. Three new complexes of platinum(II) with doxycycline, oxytetracycline and chlortetracycline and their antimicrobial activity. J. Braz. Chem. Soc. [online]. 2006, vol.17, n.8, pp. 1627-1633. ISSN 0103-5053.  http://dx.doi.org/10.1590/S0103-50532006000800021.

This paper reports on the synthesis and characterization of three new platinum(II) complexes with oxytetracycline, doxycycline and chlortetracycline by elemental analysis, IR and 195Pt RMN spectroscopies. Doxycycline interactions with PtII ions as a function of the pH were studied by 1H NMR. All the investigated tetracyclines form 1:1 complexes with PtII via the oxygen of the hydroxyl group and oxygen of the amide group at ring A. The minimal inhibitory concentrations (MIC) of the ligands and those of their PtII compounds were determined in two sensitive strains (E. coli HB 101 and E. coli ATCC 25922) and in a resistant one (E. coli HB101/pBR322). Platinum complex of doxycycline is twice as potent as the free antibiotic in the resistant strain. Octanol/water partition coefficients of the complexes were determined. Increasing lipophilicity enhances antimicrobial activity in the resistant strain.

Keywords : tetracycline derivatives; platinum complexes; antimicrobial activity; bacterial resistance.

        · abstract in Portuguese     · text in English     · pdf in English