Sinteza i karakterizacija kompleksa zlata(III) sa nekim dipeptidima

Nakon otkrića antitumorske aktivnosti cisplatine, posebna pažnja je posvećena ispitivanju kompleksa zlata(III) kao potencijalnih antitumorskih agenasa, zbog činjenice da su Au(III) i Pt(II) izoelektronski joni (d8 elektronska konfiguracija) i da formiraju kvadratno-planarne komplekse. Usled potencijalne primene kompleksa zlata(III) u lečenju tumora, u toku poslednjih nekoliko decenija,intenzivno su izučavane reakcije Au(III) jona sa biološki važnim ligandima, kao što su aminokiseline, peptidi i proteini. Mehanizam antitumorskog delovanja kompleksa zlata(III) još uvek nije u potpunosti razjašnjen i predstavlja predmet intenzivnih izučavanja. Ispitivanje reakcija kompleksa zlata(III) sa peptidima je od velikog značaja za definisanje mehanizma antitumorskog i toksičnog delovanja ovih kompleksa.After discovery of the anticancer properties of cisplatin, special attention was devoted to evaluation of gold(III) complexes as potential antitumor agents due to the fact that both Pt(II) and Au(III) ions possess the same d8 electronic configuration and preferentially form square-planar complexes. The possible involvement of gold(III)complexes in cancer treatment initiated an interest in the area of gold(III) interactions with different biologically important ligands such as amino acids, peptides and proteins. However, the mechanism of antitumor activity of gold(III) complexes is not yet completely understood and further investigation of this subject is required. A better knowledge of the gold(III) reactions with peptides contributes to the future development of gold(III) complexes as potential antitumor agents and also has importance in relation to the severe toxicity of gold-based drugs

In vitro antimicrobial activity and cytotoxicity of nickel(II) complexes with different diamine ligands

Three diamines, 1,3-propanediamine (1,3-pd), 2,2-dimethyl-1,3-propanediamine (2,2-diMe-1,3-pd) and (+/-)-1,3-pentanediamine (1,3-pnd), were used for the synthesis of nickel(II) complexes 1-3, respectively, of the general formula [Ni(L)(2)(H2O)(2)]Cl-2. The stoichiometries of the complexes were confirmed by elemental microanalysis, and their structures were elucidated by spectroscopic (UV-Vis and IR) and molar conductivity measurements. The complexes 1-3, along with NiCl2 center dot 6H(2)O and the diamine ligands, were evaluated against a panel of microbial strains that are associated with skin, wound, urinary tract and nosocomial infections. The obtained results revealed no significant activity of 1-3 against the investigated bacterial strains. On the other hand, they showed good antifungal activity against pathogenic Candida strains, with minimum inhibitory concentration (MIC) values in the range from 15.6 to 62.5 mu g mL(-1). The best anti-Candida activity was observed for complex 2 against C. parapsilosis, while the least susceptible to the effect of the complexes was C. krusei. The antiproliferative effect on normal human lung fibro-blast cell line MRC-5 was also evaluated in order to determine the therapeutic potential of nickel(II) complexes 1-3. These complexes showed lower negative effects on the viability of the MRC-5 cell line than the clinically used nystatin and comparable selectivity indexes to that of this antifungal drug

Investigation of p-chloroaniline formation in the reactions between different endodontic irrigants

The aim of this study was to determine whether p-chloroaniline (PCA) is formed in the reactions of sodium hypochlorite (NaOCl) with final rinse chlorhexidine (CHX), QMix (combination of ethylenediaminetetraacetic acid (EDTA), CHX and detergent) and EDTA/CHX solutions by thin-layer chromatography (TLC), proton nuclear magnetic resonance (1H NMR) and infrared (IR) spectroscopy. Commercially available 5.25% NaOCl solution was mixed with 2% CHX and QMix in 1:1 (v/v) ratio at room temperature. Furthermore, 2% CHX was associated with 17% EDTA under the same experimental conditions. The obtained solutions were evaluated qualitatively for color changing, precipitate and/or bubble formation and analyzed by TLC chromatography. The association products were investigated by spectroscopic (1H NMR and IR) methods in order to determine whether they contain PCA. It was found that interactions between NaOCl/CHX and CHX/EDTA led to forming of brown and white precipitate. When NaOCl was mixed with QMix, an orange-brown precipitate was formed. PCA was not detected as a product of the reactions between NaOCl and final rinse solutions of CHX, QMix and EDTA/CHX association.Publishe

Copper(II) complexes with different diamines as inhibitors of bacterial quorum sensing activity

Three copper(II) complexes, trans-[Cu(1,3-pd)(2)Cl-2]center dot H2O (Cu1; 1,3-pd is 1,3-propanediamine), trans-[Cu(2,2-diMe-1,3-pd)(2)Cl-2] (Cu2; 2,2-diMe-1,3-pd is 2,2-dimethyl-1,3-propanediamine) and trans-[Cu(1,3-pnd)(2)Cl-2]center dot H2O (Cu3; 1,3-pnd is (+/-)-1,3-pentanediamine), were synthesized and structurally characterized by elemental microanalyses, IR, electronic absorption and reflectance spectroscopy and molar conductivity measurements. The antimicrobial efficiency of the complexes against four clinically relevant microorganisms and their antiproliferative effect on the normal human lung fibroblast cell line MRC-5 were evaluated. Since in many bacteria, pathogenicity is regulated by an intercellular communication process called quorum sensing (QS), the effect of the copper(II) complexes Cu1-3 on bacterial QS was examined. The obtained results showed that these complexes inhibited violacein production in Chromobacterium violaceum CV026, indicating their anti-QS activity via the homoserine lactone (HSL) pathway. Two biosensor strains were used to determine which pathway, C4-HSL (N-butanoylhomoserine lactone) or 3OC12-HSL (N-(3-oxododecanoyl) homoserine lactone), was affected by the copper(II) complexes. The biological activities of the copper(II) complexes were compared with those for the nickel(II) complexes of the general formula trans-[Ni(L)(2)(H2O)(2)]Cl-2 (L = 1,3-pd, 2,2-diMe-1,3-pd and 1,3-pnd)

Copper(II) complexes with aromatic nitrogen-containing heterocycles as effective inhibitors of quorum sensing activity in Pseudomonas aeruginosa

Five copper(II) complexes 1-5 with aromatic nitrogen-containing heterocycles, pyrimidine (pm, 1), pyrazine (pz, 2), quinazoline (qz, 3 and 4) and phthalazine (phtz, 5) have been synthesized and structurally characterized by spectroscopic and single-crystal X-ray diffraction techniques. The crystallographic results show that, dependent on the ligand structure, complexes 1-5 are of different nuclearity. The antimicrobial efficiency of complexes 1-5 has been evaluated against three clinically relevant microorganisms and none of the complexes showed significant growth inhibiting activity, with values of minimum inhibitory concentrations (MIC) in the mM range. Since in many bacteria, pathogenicity and virulence are regulated by intercellular communication processes, quorum sensing (QS), the effect of the copper(II) complexes on bacterial QS has also been examined. The results indicate that the investigated complexes inhibit violacein production in Chromobacterium violaceum CV026, suggesting an anti-QS activity. In order to differentiate, which of the QS pathways was affected by the copper(II) complexes, three biosensor strains were used: the PAO1 Delta rhlIpKD-rhlA and the PA14-R3 Delta lasIPrsaI lux strain to directly measure the levels of C4-HSL (N-butanoyl-homoserine lactone) and 3OC12-HSL (N-3-oxo-dodecanoyl- homoserine lactone), respectively, and PAO1 Delta pqsA mini-CTX luxPpqsA for the detection of AHQs (2-alkyl-4-quinolones). Complexes 1-5 were shown to be efficient inhibitors of biofilm formation of the human opportunistic pathogen Pseudomonas aeruginosa PAO1, with the qz-containing complex 3 being the most active. Finally, the most anti-QS-active complexes 1 and 3 showed synergistic activity against a multi-drug resistant clinical isolate of P. aeruginosa, when supplied in combination with the known antibiotics piperacillin and ceftazidime

Supplementary data for the article: Glišić, B. Đ.; Nikodinovic-Runic, J.; Ilic-Tomic, T.; Wadepohl, H.; Veselinović, A.; Opsenica, I. M.; Djuran, M. I. Synthesis, Cytotoxic Activity and DNA-Binding Properties of Copper(II) Complexes with Terpyridine. Polyhedron 2018, 139, 313–322. https://doi.org/10.1016/j.poly.2017.11.008

Supplementary material for: [https://doi.org/10.1016/j.poly.2017.11.008]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2581

Silver(I) complexes with phthalazine and quinazoline as effective agents against pathogenic Pseudomonas aeruginosa strains

Five silver(I) complexes with aromatic nitrogen-containing heterocycles, phthalazine (phtz) and quinazoline (qz), were synthesized, characterized and analyzed by single-crystal X-ray diffraction analysis. Although different AgX salts reacted with phtz, only dinuclear silver(I) complexes of the general formula {[Ag(X-O)(phtz-N)](2)(mu-phtz-N,N')(2)} were formed, X = NO3- (1), CF3SO3- (2) and ClO4- (3). However, reactions of qz with an equimolar amount of AgCF3SO3 and AgBF4 resulted in the formation of polynuclear complexes, {[Ag(CF3SO3-O)(qz-N)](2)}(n) (4) and {[Ag(qz-N)][BF4]}(n) (5). Complexes 1-5 were evaluated by in vitro antimicrobial studies against a panel of microbial strains that lead to many skin and soft tissue, respiratory, wound and nosocomial infections. The obtained results indicate that all tested silver(I) complexes have good antibacterial activity with MIC (minimum inhibitory concentration) values in the range from 2.9 to 48.0 mu M against the investigated strains. Among the investigated strains, these complexes were particularly efficient against pathogenic Pseudomonas aeruginosa (MIC = 2.9-29 mu M) and had a marked ability to disrupt clinically relevant biofilms of strains with high inherent resistance to antibiotics. On the other hand, their activity against the fungus Candida albicans was moderate. In order to determine the therapeutic potential of silver(I) complexes 1-5, their antiproliferative effect on the human lung fibroblastic cell line MRC5, has been also evaluated. The binding of complexes 1-5 to the genomic DNA of P. aeruginosa was demonstrated by gel electrophoresis techniques and well supported by molecular docking into the DNA minor groove. All investigated complexes showed an improved cytotoxicity profile in comparison to the clinically used AgNO3.This is the peer reviewed version of the paper: Glisić, B., Šenerović, L., Comba, P., Wadepohl, H., Veselinović, A., Milivojević, D., Djuran, M. I.,& Nikodinović-Runić, J.. (2016). Silver(I) complexes with phthalazine and quinazoline as effective agents against pathogenic Pseudomonas aeruginosa strains. in Journal of Inorganic Biochemistry Elsevier Science Inc, New York., 155, 115-128. [https://doi.org/10.1016/j.jinorgbio.2015.11.026

Zinc(II) Complexes with Dimethyl 2,2 '-Bipyridine-4,5-dicarboxylate: Structure, Antimicrobial Activity and DNA/BSA Binding Study

Two zinc(II) complexes with dimethyl 2,2 '-bipyridine-4,5-dicarboxylate (py-2py) of the general formula [Zn(py-2py)X-2], X = Cl- (1) and Br- (2) were synthesized and characterized by NMR, IR and UV-Vis spectroscopy and single-crystal X-ray diffraction analysis. Complexes 1 and 2 are isostructural and adopt a slightly distorted tetrahedral geometry with values of tetrahedral indices tau(4) and tau'(4) in the range of 0.80-0.85. The complexes were evaluated for their in vitro antimicrobial activity against two bacterial (Pseudomonas aeruginosa and Staphylococcus aureus) and two fungal strains (Candida albicans and Candida parapsilosis), while their cytotoxicity was tested on the normal human lung fibroblast cell line (MRC-5) and the model organism Caenorhabditis elegans. Complex 1 showed moderate activity against both Candida strains. However, this complex was twofold more cytotoxic compared to complex 2. The complexes tested had no effect on the survival rate of C. elegans. Complex 2 showed the ability to inhibit filamentation of C. albicans, while complex 1 was more effective than complex 2 in inhibiting biofilm formation. The interactions of complexes 1 and 2 with calf thymus DNA (ct-DNA) and bovine serum albumin (BSA) were studied to evaluate their binding affinity toward these biomolecules