Sinteza i karakterizacija nekih metal(II) i metal(III) kompleksa sa diaminopolikarboksilatnim ligandima

U prvom delu ove doktorske disertacije, na osnovu rezultata rendgenske strukturne analize, opisana je kristalna struktura {[Sr2(1,3-pdta)(H2O)6].H2O}n kompleksa. Nađeno je da se u koordinacionoj sferi svakog Sr(II) jona, pored četiri molekula vode, nalaze jedan atom azota i četiri atoma kiseonika karboksilnih grupa koje potiču iz 1,3-propandiamin-N,N,N’,N’-tetraacetato liganda (1,3-pdta). Dva Sr(II) jona u {[Sr2(1,3-pdta)(H2O)6].H2O}n kompleksu su međusobno povezani preko diaminskog lanca 1,3-pdta liganda. Pored toga, svaki Sr(II) jon je mostno povezan preko dva karboksilna kiseonikova atoma i molekula vode sa dva susedna Sr(II) jona. Na bazi rezultata difrakcije rendgenskih zraka sa prahova i rezultata IR spektroskopije za različite M(II)-1,3-pdta komplekse, ispitivan je način koordinacije 1,3-pdta liganda u zavisnosti od veličine centralnih jona metala, kao i tip kompleksa koji pri tome nastaje. Rezultati ovih ispitivanja su objavljeni u radu: U. Rychlewska, B. Warżajtis, D. D. Radanović, N. S. Drašković, I. M. Stanojević and M. I. Djuran, Polyhedron, 30 (2011) 983-989. U drugom delu disertacije opisana je sinteza i spektroskopska (UV-Vis i IR spektri) karakterizacija kompleksa nikla(II) i bakra(II) sa novim heksadentatnim (±)-1,3-pentandiamin-N,N,N’,N’-tetraacetato (1,3-pndta) i pentadentatnim (±)-1,3-pentandiamin-N,N,N’-triacetato (1,3-pnd3a) ligandima. Ovi ligandi su strukturno slični sa ranije opisanim heksadentatnim 1,3-propandiamin-N,N,N’,N’- tetraacetato (1,3-pdta) i pentadentatnim 1,3-propandiamin-N,N,N’-triacetato (1,3-pd3a) ligandima. Rezultati rendgenske strukturne analize dobijeni za oktaedarski Mg[Ni(1,3-pndta)]10H2O kompleks ukazuju da prisustvo etil- supstituenta na α-ugljenikovom atomu doprinosi stvaranju novog hiralnog centra, što ima za posledicu građenje izomera (ΔΛΔ (R) i ΛΔΛ (S)) koji se razlikuju u konfiguraciji ovog centra (R ili S). Nađeno je da δ uvijena forma leđnog diaminskog prstena uslovljava Λ konfiguraciju, dok je u slučaju λ uvijene forme ovog prstena potvrđena Δ konfiguracija [Ni(1,3-pndta)]2- kompleksa. U slučaju stereoizomera ΔΛΔ (R) i ΛΔΛ (S) nađeno je da etil grupa zauzima ekvatorijalni položaj na centralnom šestočlanom diaminskom prstenu. Elektronski apsorpcioni i infra-crveni spektri Ni(II) i Cu(II) kompleksa sa heksadentatno koordinovanim 1,3-pndta ligandom (Mg[Ni(1,3-pndta)]10H2O i Mg[Cu(1,3- pndta)].7H2O) i pentadentatno koordinovanim 1,3-pnd3a ligandom (Mg[Ni2(1,3- pnd3a)2]8H2O i Mg[Cu2(1,3-pnd3a)2].7H2O) su poređeni sa odgovarajućim spektrima analognih Mg[Ni(1,3-pdta)].8H2O i Mg[Cu(1,3-pdta)].8H2O i Mg[Cu2(1,3-pd3a)2].7H2O kompleksa poznatih kristalnih struktura. Rezultati ovih ispitivanja su objavljeni u radu: N. S. Drašković, D. D. Radanović, U. Rychlewska, B. Warżajtis, I. M. Stanojević and M. I. Djuran, Polyhedron, 43 (2012) 185-193. U trećem delu disertacije opisana je sinteza i karakterizacija serije hrom(III) kompleksa sa heksadentatno koordinovanim ()-1,3-pentandiamin- N,N,N,N-tetraacetato (1,3-pndta) ligandom i Na+, K+ i Ca2+ jonima kao kontra- katjonima. Struktura ovih kompleksa je potvrđena na osnovu rendgenske strukturne analize. Ispitivan je uticaj kontra-katjona i supstituisanog diaminskog prstena na samoorganizaciju molekula i stepen hidratacije molekula u kristalima. Različiti načini vezivanja karboksilnih grupa za jone metala uslovljavaju formiranje 3D, 2D i 1D polimernih struktura. Elektronski apsorpcioni i 1H NMR spektri [Cr(1,3-pndta)]- kompleksa su diskutovani u odnosu na [Cr(1,3-pdta)]- komplekse poznatih kristalnih struktura. Rezultati ovih ispitivanja su objavljeni u radu: B. Warżajtis, U. Rychlewska, D. D. Radanović, I. M. Stanojević, N. S. Drašković, N. S. Radulović and M. I. Djuran, Polyhedron, 67 (2014) 270-278.The first part of this thesis deals with synthesis and the X-ray characterization of the missing homonuclear s-block metal complex {[Sr2(1,3-pdta)(H2O)6].H2O}n. In the title compound, the hexadentate 1,3-propanediaminetetraacetate (1,3-pdta) ligand joins to two Sr(II) centers via the diamine chain. Moreover, each Sr(II) is bridged through two carboxylate O atoms and a water molecule to two neighboring Sr(II) ions. The coordination sphere around each Sr(II) ion consists of one diamine nitrogen, four carboxylate oxygens and four water molecules. Comparison with the previously reported M(II)-1,3-pdta complexes reveals that increasing of the ion size results in incorporation of water molecules into its first coordination sphere and consequent increase of the C.N. from six to seven or eight while keeping the hexadentate coordination mode of the ligand. Further increase of the metal ion size leads to the loss of the chelating properties of the diamine and formation of bis-tridentate complex. Associated with it is the change in the binding mode of the carboxylate groups. This forms the basis for classification of the divalent metal 1,3-pdta complexes into five distinct structural classes. Additionally, in the present study the X-ray powder diffraction and IR spectroscopy were used for distinguishing different structural types of M(II)-1,3-pdta complexes including Ba[Ba(1,3- pdta)]·2H2O which has been used for their preparation. The above mentioned results have been published in the paper: U. Rychlewska, B. Warżajtis, D. D. Radanović, N. S. Drašković, I. M. Stanojević and M. I. Djuran, Polyhedron, 30 (2011) 983-989. In the second part of this thesis, structural variations modulated by ethyl side group have been analyzed for nickel(II) and copper(II) complexes with (±)-1,3- Summary IV pentanediamine-N,N,N’,N’-tetraacetate ligand (1,3-pndta) and its pentadentate derivative (±)-1,3-pentanediamine-N,N,N’-triaacetate (1,3-pnd3a). X-ray results obtained for the octahedral 1,3-pndta-Ni(II) complex indicate the distinct correlation of the central chirality of the metal with the chirality at the diamine α-carbon, which leads to the formation of a racemic mixture of ΔΛΔ(R) and ΛΔΛ(S) enantiomeric anionic complexes, where the R and S labels designate the absolute configuration at the ligand (ethyl-substituted) stereogenic center. These stereoisomers are those required to maintain an equatorial ethyl group on the central six-membered chelate ring, whose conformation is λ twist-boat for the ΔΛΔ isomer and δ twist-boat for the ΛΔΛ isomer. Ethyl group discernibly affects the variation of the Ni–N and Ni–O bond lengths compared to the analogous complex lacking the substitution of one of the diastereotopic diamine CH2 hydrogens and functions as steric bulkiness which hampers an efficient and of high symmetry packing, observed in the crystals of the parent complex. The infrared and electronic absorption spectra of hexadentate Mg[Ni(1,3- pndta)]10H2O and Mg[Cu(1,3-pndta)].7H2O, and pentadentate Mg[Ni2(1,3- pnd3a)2].8H2O and Mg[Cu2(1,3-pnd3a)2].7H2O complexes are presented and discussed in comparison with those of the analogous Mg[Ni(1,3-pdta)].8H2O, Mg[Cu(1,3-pdta)].8H2O and Mg[Cu2(1,3-pd3a)2].7H2O complexes of known crystal structures. The obtained results from this investigation has been published in: N. S. Drašković, D. D. Radanović, U. Rychlewska, B. Warżajtis, I. M. Stanojević and M. I. Djuran, Polyhedron, 43 (2012) 185-193. Finally in this thesis, series of Na+, K+ and Ca2+ salts of chromium(III) complexes with the hexadentate ()-1,3-pentanediamine-N,N,N,N-tetraacetate (1,3-pndta) ligand was evaluated. The extent of distortion exhibited in the geometry of these octahedral complexes was computed and related to the configuration at the metal center and the ligand stereogenic center. The materials have been used to investigate the effect of the counter ion and the diamine ring substitution on the self organization and degree of hydration of these molecules in crystals. Various modes of carboxylate binding to metal atoms have been related to the formation of 3D, 2D and 1D polymeric structures. The electronic absorption and 1H NMR spectra of 1,3-pndta-Cr(III) complexes are discussed in relation to those of 1,3-pdta-Cr(III) complex (1,3-propanediamine-N,N,N,N-tetraacetate ion) of known structure. The results of this investigation has been published in: B. Warżajtis, U. Rychlewska, D. D. Radanović, I. M. Stanojević, N. S. Drašković, N. S. Radulović and M. I. Djuran, Polyhedron, 67 (2014) 270-278

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)

Synthesis and structural analysis of polynuclear silver(I) complexes with 4,7-phenanthroline

New polynuclear silver(I) complexes, [Ag(CF3SO3)(4,7-phen)(CH3CN)]n (1) and [Ag(PO2F2)(4,7-phen)]n (2), were synthesized by the reaction of 4,7-phenanthroline (4,7-phen) and the corresponding AgX salt (X = CF3SO3 - and PF6 -) in 1:2 mole ratio, respectively, in methanol/acetone (1:1 volume ratio) at room temperature. The characterization of the complexes was established on the basis of elemental microanalysis, IR and NMR (1H and 13C) spectroscopic techniques, while their crystal structures were determined by single-crystal X-ray diffraction analysis. The results of spectroscopic and crystallographic analyses revealed that in these complexes, 4,7- phen behaves as a bridging ligand between two metal ions, while the remaining coordination sites of the Ag(I) ions are occupied by the oxygen atom of CF3SO3 - and an acetonitrile nitrogen atom in 1 or by two oxygen atoms from two PO2F2 -, formed after hydrolysis of PF6 -, in 2. In the solid state, both complexes are coordination polymers in which the geometry around the Ag(I) ions is distorted tetrahedral

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

Correction to: Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

The original version of this article unfortunately contained a mistake

Copper(II) complexes of aminopolycarboxylate ligands with N2O2, N2O3 and N2O4 donor sets. The relationship between the ligand structure and molecular geometry of the complex

The article presents an overview of the results achieved during the last several decades on the synthesis and structural characterization of copper(II) complexes with different aminopolycarboxylates. Considering the structural varieties in designing aminopolycarboxylate ligands and significant stereochemical flexibility of the corresponding copper(II) complexes to adopt a wide range of coordination geometries, this review is mainly focused on the results related to the crystallographic characterization of the synthesized complexes. The ligands used for the synthesis of copper(II) complexes described in this article contain two amine nitrogen atoms and different number of the carboxylate oxygen donor atoms (N2O2, N2O3 and N2O4-type of ligands). Giving the importance to the biological relevance of the Cu(II) ion and broad aspects of potential application of aminopolycarboxylate ligands in human practice, the presented results could have some important implications for coordination chemists dealing with structural properties of aminopolycarboxylate-copper(II) complexes and their potential medicinal and biological applications

Early effects of ionizing radiation on rat brain NTPDase activity

IUBMB 50th Anniversary Symposium, Jul 02-07, 2005, Budapest, Hungar

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

Three copper(II) complexes, trans-[Cu(1,3-pd)2Cl2]·H2O (Cu1; 1,3-pd is 1,3-propanediamine), trans-[Cu(2,2-diMe-1,3-pd)2Cl2] (Cu2; 2,2-diMe- -1,3-pd is 2,2-dimethyl-1,3-propanediamine) and trans-[Cu(1,3-pnd)2Cl2]·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]Cl2 (L = 1,3-pd, 2,2-diMe-1,3-pd and 1,3-pnd). [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 172036 and Grant no. 173048

Interaction of Gold Nanoparticles with Rat Brain Synaptosomal Plasma Membrane Na+/K+ - Atpase and Mg2+-Atpase

The aim of the work was to investigate the interaction between borate capped gold nanoparticles (NPs) and the rat brain synaptosomal plasma membranes (SPM), as well as the effects of these NPs on SPM Na+/K+ - ATPase and Mg2+-ATPase activity. The changes in the UV-vis spectra of NPs and SPM assembly suggested the agglomeration and precipitation of NPs. FTIR measurements indicated that both protein -SH and -NH2 groups and positively charged membrane fragments were implicated in the adhesion of SPM to the surface of NPs. AFM showed an increase in the particularization of the SPM material after mixing with gold NPs. Influence of gold NPs on Na+/K+-ATPase and Mg2+-ATPase activity was investigated as the function of NPs and protein concentration, preincubation time and also in the presence of various concentrations of ouabain, the specific enzyme inhibitor. NPs induced the stimulation of Na+/K+-ATPase activity for more than 100%, since Mg2+-ATPase activity reminded unaffected. We propose that this stimulation of enzyme activity was a consequence of an increase of the active surface of membranes