Microcalorimetric and Spectroscopic Investigation of the Antibacterial Properties of Cationic Ytterbium(III)–Porphyrin Complexes Lacking Charged Peripheral Groups

Abstract

The antibacterial activities towards Escherichia coli of two cationic Yb(III)-monoporphyrin complexes, [Yb(III)(TMP)(H2O)3]Cl (1) and [Yb(III)(TTP)(H2O)3]Cl (2), were investigated at the cellular and sub-cellular levels. The biological effects of the complexes on the growth of E. coli were evaluated by microcalorimetry and by analysis of the resulting metabolic thermogenic curves, from which IC50 values and metabolic parameters such as growth rate and generation time were derived. At the subcellular level, DNA-binding experiments were performed by means of UV/VIS- and fluorescence-titration experiments, as well as by near-infrared (NIR) emission, which revealed that 1 and 2 strongly bind to herring-sperm DNA (HS-DNA), though by different binding modes.

Synthesis, crystal structure and action on Escherichia coli by microcalorimetry of copper complexes with 1,10-phenanthroline and amino acid

“…This reveals that complex 5 has the strongest antibacterial activity and complex 6 has the weakest antibacterial activity. Except complex 6, IC 50 of these copper complexes on E. coli are higher than that of some antibiotics such as amoxicillin sodium (1.6 mg/L) and cefuroxime sodium (2.0 mg/L) [37], but lower than that of some reported complexes (schiff bases Mo (VI) complex M(PT) 2 , 433 mg/L [38], porphyrin ytterbium(III) complex, 143 mg/L [39]). …”

A Perspective on the Trends and Challenges Facing Porphyrin‐Based Anti‐Microbial Materials

“…The study was further extended to antibacterial activities towards E. coli by two cationic Yb III ‐monoporphyrin complexes, Yb(TMP) and [Yb III (TTP)(H 2 O) 3 ] + Cl − (Yb(TTP)) (TTP = 5,10,15,20‐tetrakis(4‐tolyl)porphyrinate dianion) at the cellular and sub‐cellular levels using same microcalorimetry. The phenomena indirectly suggest an inhibitory effect of the two cationic porphyrinates, which could explain why Yb(TMP) has higher antibacterial activity than Yb(TTP) …”

Luminescent diagnostics of skin defects in the near-infrared range

“…7 Further studies were carried out on two cationic Yb 3þ -complexes: 5,10,15,20-tetrakis(4-methoxyphenyl)porphyrin and 5,10,15,20tetrakis(4-tolyl)porphyrin. 8 Their antibacterial activity was tested at cellular and intracellular levels against Escherichia coli. The binding character of Yb-complexes with DNA molecule was studied at the intracellular level by spectroscopy, and it was concluded that Yb-complex of 5,10,15,20-tetrakis(4-methoxyphenyl) porphyrin, which showed the higher activity, is a promising agent for an intercalating antimicrobial therapy.…”