Joanna Drzeżdżon

Characterization and cytotoxic effect of aqua-(2,2′,2′′-nitrilotriacetato)-oxo-vanadium salts on human osteosarcoma cells

The use of protonated N-heterocyclic compound, i.e. 2,2′-bipyridinium cation, [bpyH+], enabled to obtain the new nitrilotriacetate oxidovanadium(IV) salt of the stoichiometry [bpyH][VO(nta)(H2O)]H2O. The X-ray measurements have revealed that the compound comprises the discrete mononuclear [VO(nta)(H2O)]− coordination ion that can be rarely found among other known compounds containing nitrilotriacetate oxidovanadium(IV) moieties. The antitumor activity of [bpyH][VO(nta)(H2O)]H2O and its phenanthroline analogue, [phenH][VO(nta)(H2O)](H2O)0.5, towards human osteosarcoma cell lines (MG-63 and HOS) has been assessed (the LDH and BrdU tests) and referred to cis-Pt(NH3)2Cl2 (used as a positive control). The compounds exert a stronger cytotoxic effect on MG-63 and HOS cells than in untransformed human osteoblast cell line. Thus, the [VO(nta)(H2O)]− containing coordination compounds can be considered as possible antitumor agents in the osteosarcoma model of bone-related cells in culture.

New type of highly active chromium(III) catalysts containing both organic cations and anions designed for polymerization of beta-olefin derivatives

The new type of catalysts designed for the olefin derivatives polymerization has been synthetized. The novel catalysts are chromium(III) salt type complexes composed of both organic cation and anion, i.e. [Cr(dipic)2][Cr(bipy)(dipic)H2O]∙2H2O and [Cr(dipic)2]Hdmbipy∙2.5 H2O. The compositions of these complexes have been confirmed by a number of instrumental methods including NMR, IR, UV-Vis, MS and elemental analysis ones. Moreover, the crystal structures of these novel catalysts were determined and reported. Furthermore, the [Cr(dipic)2][Cr(bipy)(dipic)H2O]∙2H2O and [Cr(dipic)2]Hdmbipy∙2.5H2O complexes have been studied towards their catalytic activity, after the activation by MMAO (modified methylaluminoxane), in the case of 2-chloro-2-propen-1-ol polymerization at 21 °C and atmospheric pressure. It has been found that novel catalysts, [Cr(dipic)2][Cr(bipy)(dipic)H2O]∙2H2O and [Cr(dipic)2]Hdmbipy∙2.5 H2O, exhibit a very high catalytic activity in the process of the polymerization of the beta-olefin derivatives. The products of a such catalyzed polymerization are the poly(allyl alcohol) derivatives.

Method for detection of hydrogen peroxide in HT22 cells

We have proposed a new method which can be applied in assessing the intracellular production of hydrogen peroxide. Using this assay we have examined the hydrogen peroxide generation during the L-glutamate induced oxidative stress in the HT22 hippocampal cells. The detection of hydrogen peroxide is based on two crucial reagents cis-[Cr(C2O4)(pm)(OH2)2]+ (pm denotes pyridoxamine) and 2-ketobutyrate. The results obtained indicate that the presented method can be a promising tool to detect hydrogen peroxide in biological samples, particularly in cellular experimental models.

Antioxidant and Cytoprotective Activity of Oxydiacetate Complexes of Cobalt(II) and Nickel(II) with 1,10-Phenantroline and 2,2′-Bipyridine

The antioxidant properties of oxydiacetate complexes of cobalt(II) and nickel(II) with 1,10-phenantroline and 2,2′-bipyridine have been investigated towards the superoxide radical using the nitro blue tetrazolium chloride (NBT) test and the cyclic voltammetry (CV). Moreover, the biological activity of the complexes under study has been investigated in the Human Dermal Fibroblasts adult (HDFa) cell line. In the first step, the cytotoxic and the antiproliferative activities of the complexes were examined. Subsequently, the cytoprotective properties of the complexes have been investigated in an oxidative stress conditions induced by H2O2.

Kinetics and thermodynamics of the reaction of iminodiacetate copper(II) complexes with 1,10-phenanthroline and 2,2′-bipyridine in aqueous, anionic, cationic and nonionic surfactants solutions

The kinetics and thermodynamics have been studied for the reactions of the copper(II) complexes with iminodiacetate (ida), 2,2′-bipyridine (bipy) and 1,10-phenanthroline (phen) as ligands. The kinetics of substitution reactions of two aqua ligands for bipy and phen in the [Cu(ida)(H2O)2] coordination compound has been studied in water and three type of aqueous solutions of the following surfactants: anionic sodium dodecyl sulfate (SDS), cationic hexadecyl trimethyl-ammonium bromide (CTAB) and nonionic t-octylphenoxypolyetoxyethanol (Triton X-100). The progress of the substitution reactions in the studied solutions was monitored spectrophotometrically using the stopped-flow method. The studies have allowed the determination of the effect of the type of surfactant solutions on the rate of the substitution reaction. Moreover, the order of studied reactions has been determined. The research performed has also allowed us to propose the reaction mechanism of the [Cu(ida)(H2O)2] binary complex with chelate ligands (bipy or phen). In addition, the thermodynamic stability of complexes under study in aqueous solutions has been examined using the potentiometric titration method. Moreover, the potential scavenging activity of the copper(II) complexes has been investigated towards the superoxide radical.

Oligomerization of 2-chloroallyl alcohol by 2-pyridinecarboxylate complex of chromium(III) - new highly active and selective catalyst

The new 2-pyridinecarboxylate (2-pic) complex of chromium(III) has been designed and synthesized as a new highly active and selective oligomerization catalyst. The crystal structure of the new compound has been determined by X-ray diffraction. The composition and purity of [Cr(2-pic)2(OH2)2]NO3 have been confirmed by several spectroscopic methods and the elemental analysis. Furthermore, the new complex has been investigated towards its catalytic activity for the oligomerization of 2-chloro-2-propen-1-ol under the atmospheric pressure and at room temperature. It has turned out that the novel catalyst exhibits a very high catalytic activity. Consequently, [Cr(2-pic)2(OH2)2]NO3 belongs to a new generation of non-metallocene catalysts.

Geometric isomerism effect on catalytic activities of bis(oxalato)diaquochromates(III) for 2-chloroallyl alcohol oligomerization

AbstractThe cis- and trans-potassium bis(oxalato)diaquochromates(III) have been studied towards their catalytic activity for the 2-chloroallyl alcohol oligomerization. The geometric isomerism effect on the oligomerization products under mild reaction conditions has been investigated. The molecular masses and tactic structures of obtained poly(2-chloroallyl alcohols) have been compared and analyzed. The mechanisms of oligomerization processes have been proposed. It has been proven that two studied complexes – cis-

Structure and characterization of physicochemical and magnetic properties of new complex containing monobridged oxygen copper(II) dinuclear cation

\hbox {K}[\hbox {Cr}(\hbox {C}_{2}\hbox {O}_{4})_{2}(\hbox {OH}_{2})_{2}]