Copper(II) Complexes with Mixed Heterocycle Ligands as Promising Antibacterial and Antitumor Species

Abstract

Complexes with mixed ligands [Cu(N-N)2(pmtp)](ClO4)2 ((1) N-N: 2,2′-bipyridine; (2) L: 1,10-phenanthroline and pmpt: 5-phenyl-7-methyl-1,2,4-triazolo[1,5-a]pyrimidine) were synthesized and structurally and biologically characterized. Compound (1) crystallizes into space group Pa and (2) in P-1. Both complexes display an intermediate stereochemistry between the two five-coordinated ones. The biological tests indicated that the two compounds exhibited superoxide scavenging capacity, intercalative DNA properties, and metallonuclease activity. Tests on various cell systems indicated that the two complexes neither interfere with the proliferation of Saccharomyces cerevisiae or BJ healthy skin cells, nor cause hemolysis in the active concentration range. Nevertheless, the compounds showed antibacterial potential, with complex (2) being significantly more active than complex (1) against all tested bacterial strains, both in planktonic and biofilm growth state. Both complexes exhibited a very good activity against B16 melanoma cells, with a higher specificity being displayed by compound (1). Taken together, the results indicate that complexes (1) and (2) have specific biological relevance, with potential for the development of antitumor or antimicrobial drugs.

Biological Activity of Triazolopyrimidine Copper(II) Complexes Modulated by an Auxiliary N-N-Chelating Heterocycle Ligands

“…Copper(II) exhibits particular traits, such as borderline acid characteristics or stereochemical and oxidation state versatility [16]. Moreover, most of the Cu(II) complexes with tps were reported as having antiparasitic [17], antitumor, or antimicrobial activity [18].…”

“…It is worth mentioning the activity of all complexes against methicillin-resistant S. aureus (MRSA). Moreover, complexes with mixed ligands [Cu(N-N) 2 (pmtp)](ClO 4 ) 2 (N-N: 2,2 -bipyridine (bpy) and phen) showed antibacterial potential against several bacterial strains, including MRSA, the extended-spectrum beta-lactamase (ESBL)-producing E. coli 5, and the multi-drug-resistant P. aeruginosa 9027, both in planktonic and biofilm growth state [18].…”

New Cobalt (II) Complexes with Imidazole Derivatives: Antimicrobial Efficiency against Planktonic and Adherent Microbes and In Vitro Cytotoxicity Features

“…The range of tested concentrations prepared from a stock solution in dimethyl-sulfoxide (DMSO) (10 mg/mL) was from 1000 to 1.9 µg/mL. After incubating the tested compounds with standard microbial suspensions at 0.5 MacFarland density (1.5 × 10 8 microbial cells/mL) for 24 h at 37 °C, the MIC was established as being the lowest concentration of the compound that inhibited the visible microbial growth in the wells, in comparison with the untreated culture [ 32 , 33 ].…”

“…In this purpose, the plates were emptied and then washed three times with sterile phosphate buffered saline (PBS) to remove the planktonic cells, and the remaining adherent cells were fixed for 5 min with cold methanol, stained for 20 min with 0.1% aqueous solution of crystal violet, and resuspended in acetic acid 33%. The MBEC corresponded to the lowest concentration that inhibited the microbial adherence, in comparison with the untreated culture [ 32 , 33 ].…”

Improvement in the Pharmacological Profile of Copper Biological Active Complexes by Their Incorporation into Organic or Inorganic Matrix

“…As a result, many copper complexes with potential therapeutic activities were developed. The biological application of these complexes extends from enzyme inhibition or species with enzyme-like activity [ 30 , 31 , 32 , 33 ] to active species with antimicrobial, anti-inflammatory or antitumor activity [ 17 , 18 , 19 , 20 , 22 , 23 , 29 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 ], aspects presented in several reviews.…”