154 research outputs found

    Binding of [Au(dien)Cl]Cl2 to Tripeptides

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

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    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

    Binding of Platinum(II) to Some Biologicaly Important Thiols

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    The reactions between [Pt(terpy)Cl+ and thiols, such as glutathione, L-cysteine, D-penicillamine and thioglycolic acid have been Studied by conventional UV-VIS spectrophotometry and H NMR spectroscopy. The second-ordero rate constants, K2, are similar for these four thiols, varying between 1.06 x 10-2 and 6.10 x 10+3 M-1 s-1 at 25Ā°C. The activation entropies have large negative values between -100 and -200 J mol-1 which are compatible with an associative A mechanism. However, L-methionine, as thioether ligand, is unreactive under the same experimental conditions. The obtained results have been analyzed in relation to the antitumor activity and toxicity of platinum(II) complexes

    Intermolecular displacement of S-bound L-methionine on platinum(II) by guanosine 5ā€²-monophosphate: Implications for the mechanism of action of anticancer drugs

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    NMR investigations of the kinetics and thermodynamics of the competitive binding of L-methionine (Met), L-histidine (His), and 5ā€²-monophosphates of guanosine (5ā€²-GMP), adenosine (5ā€²-AMP), thymidine (5ā€²-TMP) and cytidine (5ā€²-CMP) to [Pt(dien)Cl]+ (dien = 1,5-diamino-3-azapentane) in aqueous solution show that 5ā€²-GMP selectively displaces S-bound Met, a finding which has implications for DNA platination by anticancer drugs in vivo

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

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    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

    Evaluation of Sustainable Development Management in EU Countries

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    The term sustainable development is used in many areas and spheres of life and is becoming a modern phenomenon determining the direction of progress of every society. Sustainable development implies continuous economic development with respect to environmental principles and focuses on overcoming conflicts between economy and ecology. The aim of this paper is to evaluate sustainable development management in EU countries through selected indicators characterizing sustainable development and its core dimensions. We present the results of an evaluation of the sustainable development of EU countries using cluster analysis. Countries that are similar in terms of sustainability are identified by cluster analysis. Four clusters were separated, the affiliation of each country to a particular cluster was determined, and the characteristics of each cluster were defined. The goal of sustainability management is to create an adequate approach to development of the economic and environmental performance, and therefore achieve sustainability. The achievements of most developed countries should be an incentive for those that are at a lower level of development. In addition, this research provides insight into some specific goals of sustainable development where some countries are lagging behind. This could be the basis for directing efforts in specific areas of sustainable development to improve their own position in such an important global issue

    Gastric Necrosis and Perforation Following Massive Gastric Dilatation in an Adolescent Girl: A Rare Cause of Acute Abdomen.

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    Gastric necrosis with perforation is a rare and potentially life-threatening condition in childhood beyond the neonatal period. We report a case of gastric necrosis and perforation of a portion of the great curvature due to a massive gastric dilatation caused by pathological aerophagia in a 13-years-old, mentally impaired adolescent girl. Despite the successful surgical treatment, the patient's condition rapidly deteriorated post-operatively and she died due to the multisystem organ failure and multiple infections. In addition, we surveyed the literature on this rare condition and assessed the preventive actions to reduce this life-treating condition

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

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    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

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    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
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