ABSTRACT
The antibacterial effect of Zn(II), tetraphenyl porphyrin (TPP), propdioxyl bridged tetraphenyl bisporphyrin 1, and its metallobisporphyrin complexes (ZnMnbisporphyrin 2 and ZnZnbisporphyrin 3) towards Staphylococcus aureus growth was investigated by microcalorimetry at 37 degrees C. Differences in their capacities to inhibit the growth metabolism of S. aureus were observed. By analyzing the power-time curves, crucial parameters such as the rate constant of bacterial growth (k), inhibitory ratio (I), and generation time (t (G)) were determined. The growth rate constant (k) of S. aureus (in the log phase) in the presence of the drugs decreased linearly with increasing concentrations of the complexes. The sequence of the antibacterial activities of these compounds tested was 3 > 2 > 1 > Zn(II) > TPP. ZnZnbisporphyrin 3 is proposed to benefit from the synergetic effects of Zn(II) and 1.
Subject(s)
Anti-Bacterial Agents/pharmacology , Metalloporphyrins/pharmacology , Porphyrins/pharmacology , Staphylococcus aureus/drug effects , Zinc Compounds/pharmacology , Anti-Bacterial Agents/chemistry , Calorimetry , Metalloporphyrins/chemistry , Microbial Sensitivity Tests , Porphyrins/chemistry , Staphylococcus aureus/growth & development , Temperature , Zinc Compounds/chemistryABSTRACT
The actions of two novel diselenide-bridged bis(porphyrin)s (1 and 2) on Staphylococcus aureus growth was investigated by microcalorimetry at 37.00 degrees C, compared with that of Na2SeO3. Differences in their capacities to inhibit the growth metabolism of S. aureus were observed. By analyzing the power-time curves, crucial parameters such as the rate constant of bacterial growth (k), inhibitory rate (I), and generation time (tG) were determined. The growth rate constant (k) of S. aureus (in the log phase) in the presence of the drugs decreased with increasing concentrations of the drugs regularly. The relationship of k and c is nearly linear for diselenide-bridged bis(porphyrin) 2. The sequence of the antibacterial activities of these selenium compounds tested was 2 > 1 > Na2SeO3.