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

Different coordination abilities of 1,7- and 4,7-phenanthroline in the reactions with copper(II) salts: Structural characterization and biological evaluation of the reaction products

The reactions between equimolar amounts of CuX2 (X = NO3− and CF3SO3−) and two aromatic nitrogen-containing heterocycles differing in the position of nitrogen atoms, 1,7- and 4,7-phenanthroline (1,7- and 4,7-phen), were performed in ethanol/methanol at room temperature. When CuX2 salts were mixed with 4,7-phen, two copper(II) complexes, [Cu(NO3)2(4,7-Hphen)2](NO3)2 (1) and [Cu(CF3SO3)(4,7- phen)2(H2O)2]CF3SO3 (2), were formed. On the other hand, in the reaction of CuX2 salts with 1,7-phen, only 1,7-HphenNO3 (3a/b) and 1,7-HphenCF3SO3 (4) were obtained as the final products. The obtained products 1–4 were characterized by spectroscopic and X-ray diffraction techniques. In the copper(II) complexes 1 and 2, the coordination geometry around the Cu(II) ion is distorted octahedral and square pyramidal, respectively. The antimicrobial potential of the copper(II) complexes 1 and 2 and corresponding compounds used for their synthesis were assessed against four different bacterial species and Candida albicans, displaying moderate growth inhibiting activity. The cytotoxic properties of the investigated complexes were also evaluated against the normal human lung fibroblast cell line (MRC-5) indicating moderate, yet more pronounced cytotoxicity than antimicrobial properties

Synthesis and spectroscopic characterization of lithium salts of copper(II) and nickel(II) complexes with 1,3-propanediamine-N,N,N',N'-tetraacetate

The complexes Li2[Ni(1,3-pdta)]•5H2O and Li2[Cu(1,3-pdta)]•5H2O (where 1,3-pdta represents the 1,3-propanediaminetetraacetate anion) have been synthesized and characterized by applying IR and UV-vis spectroscopy. The obtained spectroscopic results of these complexes are discussed in relation to those for Mg[M(1,3-pdta)].8H2O complexes (M = Ni(II) and Cu(II)) of known crystal structure

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

Conformational study of Co(II), Ni(II), and Cr(III) complexes of the edta-type: Crystal structure of 1D polymeric trans(O6)-Ba[Co(1,3-pddadp)] · 8H2O complex stabilized by infinite water tapes

The trans(O6) isomer of the Ba[Co(1,3-pddadp)] • 8H2O complex (where 1,3-pddadp represents hexadentate 1,3-propanediamine-N,N′-diacetate-N,N′-di-3-propionate ion) has been prepared and characterized by X-ray crystallography. In the crystal structure the complex cations and anions are bridged by carboxylate oxygen atoms from the in-plane coordinated glycinate rings (G-rings) of [Co(1,3-pddadp)]2- and by the barium-coordinated water molecules, thus forming 1D polymeric chains, separated by infinite water tapes hydrogen bonded to the [Co(1,3-pddadp)]2- carboxylate oxygens from the out-of-plane β-alaninate rings (R-rings). Conformational analysis of the three possible geometrical isomers: trans(O5), trans(O5O6), and trans(O6) of the [Co(1,3-pddadp)]2- complex, with ligand acting as hexadentate, as well as of the corresponding complexes of Ni(II) and Cr(III) has been performed using the consistent force field (CFF) method, with the parameters developed previously for edta-type complexes of chromium(III) and supplemented with new parameters for cobalt(II) and nickel(II). The energy-minimized structure of the trans(O5O6) isomer represents the global minimum for the [M(1,3-pddadp)]n- (M = Co(II), Ni(II), and Cr(III)) species. The occurrence of the least energetically favored trans(O6) isomer in a crystal and the exceptional conformation of the axially oriented β-alaninate rings can be accounted for by the stabilizing role of the infinite tapes of planar cyclic water pentamers and hexamers which act as a "glue" to reinforce the coordination polymeric chains

SINTEZA I SPEKTROSKOPSKA KARAKTERIZACIJA NOVOG RASTVORA U ČVRSTOM STANJU KOJI SADRŽI Mg(II) I Cu(II) KOMPLEKSE SA HEKSADENTATNIM 1,3-PROPANDIAMIN-N,N,N’,N’-TETRAACETATO (1,3-PDTA) LIGANDOM: IN VITRO ANTIFUNGALNA AKTIVNOST 1,3-PDTA-Cu(II) KOMPLEKSA

New solid solution containing Mg(II) and Cu(II) complexes with hexadentate 1,3-propanediamine-N,N,N’,N’-tetraacetate ligand (1,3-pdta), [Mg(H2O)6][Mg0.5Cu0.5(1,3-pdta)].2H2O was synthesized and structurally characterized by elemental microanalyses, molar conductivity and spectroscopic (IR and UV-Vis) measurements. The spectroscopic data of [Mg(H2O)6][Mg0.5Cu0.5(1,3-pdta)].2H2O were compared with those for [Mg(H2O)6][Cu(1,3-pdta)].2H2O  complex of the known molecular structure determined by single-crystal X-ray diffraction analysis (Rychlewska et al., 2000). In vitro growth inhibition activity of [Mg(H2O)6][Mg0.5Cu0.5(1,3-pdta)].2H2O and [Mg(H2O)6][Cu(1,3-pdta)].2H2O against Colletotrichum acutatum and their effects on this fungus sporulation level are investigated. The obtained results showed that the highest percentage of inhibition for mycelium growth was achieved at a concentration of 500 µg/mL for the investigated complexes. The biological activities of the investigated complexes were compared with those for the commercial formulation of fungicide captan (Method 480 SC). Opisana je sinteza i spektroskopska karakterizacija (IR i elektronski apsorpcioni spektri) novog rastvora u čvrstom stanju koji sadrži Mg(II) i Cu(II) komplekse sa 1,3-propandiamin-N,N,N',N'-tetraacetato (1,3-pdta) ligandom, [Mg(H2O)6][Mg0.5Cu0.5(1,3-pdta)].2H2O. Spektroskopski podaci za [Mg(H2O)6][Mg0.5Cu0.5(1,3-pdta)].2H2O kompleks su upoređeni sa odgovarajućim podacima za [Mg(H2O)6][Cu(1,3-pdta)].2H2O kompleks poznate kristalne strukture. Ispitivana je in vitro antimikrobna aktivnost [Mg(H2O)6][Mg0.5Cu0.5(1,3-pdta)].2H2O i [Mg(H2O)6][Cu(1,3-pdta)].2H2O kompleksa prema fitopatogenoj gljivi Colletotrichum acutatum, koja uzrokuje antraknozu. Analiziran je uticaj različitih koncentracija [Mg(H2O)6][Mg0.5Cu0.5(1,3-pdta)].2H2O i [Mg(H2O)6][Cu(1,3-pdta)].2H2O kompleksa na rast micelija i na intenzitet sporulacije gljive. Dobijeni rezultati su pokazali da ovi kompleksi imaju najveću aktivnost pri koncentraciji od 500 µg/mL. Biološka aktivnost [Mg(H2O)6][Mg0.5Cu0.5(1,3-pdta)].2H2O i [Mg(H2O)6][Cu(1,3-pdta)].2H2O je upoređena sa odgovarajućom aktivnošću komercijalnog fungicida 480 SC (Kaptan)

Cobalt(III) complexes with (±)-1,3-pentanediamine-<i>N,N,N’,N’</i>-tetraacetate. The influence of nature of alkali and alkaline earth metal counter cations on the supramolecular association of the complex

The coordination of hexadentate (±)-1,3-pentanediamine-N,N,N’,N’-tetraacetate (1,3-pndta) ligand with Co(III) has been investigated. Four octahedral [Co(1,3-pndta)]− complexes containing different counter cations, Li[Co(1,3-pndta)]⋅4H2O (1a), Li[Co(1,3-pndta)]⋅2H2O (1b), K[Co(1,3-pndta)]⋅H2O (1c) and Ca[Co(1,3-pndta)]2⋅5H2O (1d), were synthesized and structurally characterized. Single-crystal X-ray diffraction analysis, IR, NMR (1H and 13C) and electronic absorption spectroscopy were used for characterization of 1a − d. The influence of the ethyl substituent of 1,3-propanediamine chain in 1,3-pndta and the nature of metal counter cation on the structural modalities of carboxylate bridging groups in 1a − d were established by comparing with the analogous [M(1,3-pdta)]n− (1,3-pdta = 1,3-propanediamine-N,N,N’,N’-tetraacetate) and [M(1,3-pndta)]n− complexes (M = Co(III), Cr(III) and Ni(II)). Our studies have shown that the supramolecular association of the complexes is primarily governed by the size of the alkali or alkaline earth metal counter cation and its templating ability, while ethyl substituents, in most cases, prevent the formation of 3D polymeric frameworks.</p