Synthesis, characterization, and antibacterial activity of three palladium(II) complexes of tetracyclines.
Pd(II) complexes with three antibiotics of the tetracycline family (tetracycline, doxycycline and chlortetracycline) were synthesized and characterized by elemental, thermogravimetric, and conductivity analyses, and infrared spectroscopy. The interactions between Pd(II) ions and tetracycline were investigated in aqueous solution by (1)H NMR. All the tetracyclines studied form 1:1 complexes with Pd(II) via the oxygen of the hydroxyl group at ring A and that of the amide group. The effect of the three complexes on the growth of bacterial strains sensitive and resistant to tetracycline was studied. The Pd(II) complex of tetracycline is practically as efficient as tetracycline in inhibiting the growth of two Escherichia coli (E. coli) sensitive bacterial strains and 16 times more potent against E. coli HB101/pBR322, a bacterial strain resistant to tetracycline. Pd(II) coordination to doxycycline also increased its activity in the resistant strain by a factor of 2.
Guerra
Wendell
W
Departamento de Química - ICEx, Universidade Federal de Minas Gerais, Avenida Antonio Carlos, 6627, 31.270-901 Belo Horizonte MG, Brazil.
de Andrade Azevedo
Elaine
E
de Souza Monteiro
Ana Raquel
AR
Bucciarelli-Rodriguez
Mônica
M
Chartone-Souza
Edmar
E
Nascimento
Andréa Maria Amaral
AM
Fontes
Ana Paula Soares
AP
Le Moyec
Laurence
L
Pereira-Maia
Elene C
EC
D000900:Anti-Bacterial Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D004926:Escherichia coli / Q000187:drug effects; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D010165:Palladium / Q000737:chemistry / Q000494:pharmacology*; D013754:Tetracyclines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D013816:Thermodynamics
D000900:Anti-Bacterial Agents; D009942:Organometallic Compounds; D013754:Tetracyclines; D010165:Palladium