41 research outputs found

    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

    Polymerase chain reaction in the identification of periodontopathogens: A reliable and satisfactory method?

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    Aggregatibacter actinomycetemcomitans is considered one of the bacterial species of etiological importance in periodontitis. The aim of this study was to evaluate the serotype of A. actinomycetemcomitans in the subgingival biofilm in subjects with periodontal health and disease. Pooled samples of subgingival plaque were taken for culture-based identification of microorganisms. Colonies suspected to be A. actinomycetemcomitans were selected for molecular identification using either multiplex or conventional PCR in serotype-specific genotyping and 16S rRNA gene sequencing. In silico analysis showed that most selected colonies belong to the genus Campylobacter, although positive signals for serotypes of A. actinomycetemcomitans were obtained with these samples. Identification of A. actinomycetemcomitans by conventional PCR for 16S rRNA with one species-specific and one universal primer was inconclusive because an almost identical signal with Campylobacter gracilis was obtained. Although PCR-based methods for the identification of A. actinomycetemcomitans are more rapid, sequencing should not be omitted. [Projekat Ministarstva nauke Republike Srbije, br. 41008 and br. 173048

    Polymerase chain reaction in the identification of periodontopathogens: A reliable and satisfactory method?

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    Aggregatibacter actinomycetemcomitans is considered one of the bacterial species of etiological importance in periodontitis. The aim of this study was to evaluate the serotype of A. actinomycetemcomitans in the subgingival biofilm in subjects with periodontal health and disease. Pooled samples of subgingival plaque were taken for culture-based identification of microorganisms. Colonies suspected to be A. actinomycetemcomitans were selected for molecular identification using either multiplex or conventional PCR in serotype-specific genotyping and 16S rRNA gene sequencing. In silico analysis showed that most selected colonies belong to the genus Campylobacter, although positive signals for serotypes of A. actinomycetemcomitans were obtained with these samples. Identification of A. actinomycetemcomitans by conventional PCR for 16S rRNA with one species-specific and one universal primer was inconclusive because an almost identical signal with Campylobacter gracilis was obtained. Although PCR-based methods for the identification of A. actinomycetemcomitans are more rapid, sequencing should not be omitted

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

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    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)

    The Surface of Sodium Tungsten Bronze Electrodes in Acid Solutions

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    At eledtrddes of sodium tungsten bronzes · of CJWic> syi;r;imetpy (0:25 hydraW,d\u27 laye~ of rion-stoiehiotnetric oxide· is.Jormed, On ·the \u27·base o0f comwn·ative considerations of results of electrochemical and: .some ; othevr me:;i~u:. . remerits the structure •of the ··surface layer is .• ptQposed,· ,a_nd, the thiekfiess\u27 . of . the. isur\u27:flace layer• eS>timated,; •Rossiblgru.eNplanati-on:s.ef\u27 •the nature• of · the rest potential arid ·N ~ .log i· ,relationship :are po1nted \u27 out; On the base\u27 .of study of • kinetics. and · mechanism,. of some simple electron exchange reactions . it \u27is concluded ·:that elei:;trical properties of the surface layer are close to· metallic

    Antiplasmodial Activity and In Vivo Bio-Distribution of Chloroquine Molecules Released with a 4-(4-Ethynylphenyl)-Triazole Moiety from Organometallo-Cobalamins

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    We have explored the possibility of using organometallic derivatives of cobalamin as a scaffold for the delivery of the same antimalarial drug to both erythro- and hepatocytes. This hybrid molecule approach, intended as a possible tool for the development of multi-stage antimalarial agents, pivots on the preparation of azide-functionalized drugs which, after coupling to the vitamin, are released with a 4-(4-ethynylphenyl)-triazole functionality. Three chloroquine and one imidazolopiperazine derivative (based on the KAF156 structure) were selected as model drugs. One hybrid chloroquine conjugate was extensively studied via fluorescent labelling for in vitro and in vivo bio-distribution studies and gave proof-of-concept for the design. It showed no toxicity in vivo (zebrafish model) as well as no hepatotoxicity, no cardiotoxicity or developmental toxicity of the embryos. All 4-(4-ethynylphenyl)-triazole derivatives of chloroquine were equally active against chloroquine-resistant (CQR) and chloroquine-sensitive (CQS) Plasmodium falciparum strains

    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
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