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Abstract The physicochemical properties of several chromium(III) complexes with ligands, such as picolinate, dipicolinate, oxalate, 2,2′-bipyridine, and 4,4′-dimethoxy-2,2′-bipyridine were investigated. First, the stability and formation constants of the synthesised chromium(III) complexes in aqueous solutions were evaluated with potentiometric titrations. In addition, the stoichiometry of each chromium(III) complex in water was analysed with conductometric titrations. Next, the potential antioxidant properties of chromium(III) compounds were determined by evaluating the ability of the synthesised complexes to reduce nitro blue tetrazolium salt. We also investigated the antimicrobial properties of the solutions of these compounds against Bacillus subtilis, Escherichia coli , Enterococcus faecalis , Pseudomonas aeruginosa , Staphylococcus aureus , and Staphylococcus epidermidis. The cytotoxic properties of chromium(III) complexes were tested using a human keratinocyte cell line (HaCaT). Highlights • The antimicrobial and cytotoxic properties of Cr(III) complexes have been studied. • The stability of the complexes in aqueous solution has been investigated. • The scavenging activities of the complexes have been studied by NBT. • The stoichiometry of the complexes in aqueous solution has been analysed. [ABSTRACT FROM AUTHOR]

The oxydiacetate complexes of copper(II) with 2,2′-bipyridine (bipy) and 1,10-phenanthroline (phen) have been investigated towards their kinetic and thermodynamic stability. The kinetics of the substitution reactions of the oxydiacetate complex of Cu 2+ with bipy and phen have been studied in two types of surfactant solutions - anionic dodecyl sulfate sodium (SDS) and cationic hexadecyl trimethyl-ammonium bromide (CTAB). The values of the observable rate constants for the studied reactions have been determined using the “Glint” program. Moreover, the thermodynamic stability of the copper(II) complexes with oda, phen and bipy in aqueous solutions has been investigated using potentiometric titration method (PT). The concentration distributions of the studied complexes as a function of pH calculated based on the values of log β pqrs have been determined. Additionally, the antioxidant activities of the oxydiacetate complexes of copper(II) with bipy and phen have been studied by the nitro blue tetrazolium (NBT) test and the cyclic voltammetry (CV) technique. [ABSTRACT FROM AUTHOR]

The crystal and molecular structures of a new dinuclear oxidovanadium(IV) complex with the N -(phosphonomethyl)iminodiacetate (pmida) ligand and the 4-amino-2-methylquinolinium ([amqH] + ) cation of the molecular formula [amqH] 4 [V 2 O 2 (pmida) 2 ]6H 2 O have been determined. The phosphonate groups in the two pmida 4− ligands form two bridges between adjacent V 4+ atoms, resulting in the formation of a [V 2 O 2 (pmida) 2 ] 4− dimer with a V 2 O 4 P 2 eight-membered ring. This is the first example of a quinoline derivative complex containing the [V 2 O 2 (pmida) 2 ] 4− ion. The susceptibility curve for the complex exhibits a maximum at approximately 10 K, indicating the presence of antiferromagnetic interactions transmitted in the crystal lattice. Furthermore, the biological properties of the complex in the concentration range 1–100 μM were investigated in relation to its cytoprotective activity against oxidative damage generated exogenously using hydrogen peroxide in the hippocampal neuronal HT22 cell line (MTT tests). The obtained results were subsequently referred to the [amqH][VO(nta)(H 2 O)]H 2 O analogue as well as trolox and ascorbic acid, used as known antioxidants. It has been established that the title compound effectively protects HT22 from oxidative damage and is a potentially good candidate for further evaluation of the mechanism of its action. [ABSTRACT FROM AUTHOR]

The crystal and molecular structure of the new copper(II) complex with nitrilotriacetate (nta) and 1,10-phenanthroline (phen) ligands of the [Cu(phen) 2 Cu(nta)(phen)] 2 [Cu(Hnta) 2 ]·20H 2 O molecular formula has been determined. The compound comprises the dianionic mononuclear entity, [Cu(Hnta) 2 ] 2− , and two monocationic dinuclear units, [Cu(phen) 2 Cu(nta)(phen)] + , in which the Cu(II) ions are bridged by one oxygen atom of the nta ligand in the rarely found μ 1,1 –O bridging mode. The complex was characterized by spectroscopic (IR, FIR and EPR) methods and magnetic measurements as well as thermogravimetry (TG). The magnetic measurements revealed an antiferromagnetic coupling between the Cu(II) ions in the dinuclear unit. Based on the experimental data supported by density functional theory (DFT) calculations the correlation between the coordination mode of the Cu(II) ions and magnetic properties of the compound studied has been discussed. [ABSTRACT FROM AUTHOR]

The oxydiacetate and iminodiacetate complexes of VO(IV) with bipy and phen are high active catalysts for the formation process of poly(2-chloroallyl alcohol) oligomers. The products obtained as the results of the oligomerization reactions after the use of catalysts undergo the thermal decomposition in the similar way. • New highly active catalysts of 2-chloro-2-propen-1-ol oligomerization were studied. • The catalytic activities are in the range 358.97–1004.70 g·mmol−1·h−1. • The oligomers thermally decompose releasing H 2 O, CO 2 , CO and HCl. • The oxydiacetate and iminodiacetate complexes of oxidovanadium(IV) are catalysts. • The oligomerization undergoes at room temperature and under atmospheric pressure. The oxydiacetate (oda) and iminodiacetate (ida) complexes of oxidovanadium(IV) with 1,10-phenantroline (phen) and 2,2′-bipyridine (bipy) have been synthesized. The six following complexes: [VO(oda)(H 2 O) 2 ], [VO(oda)(bipy)]·2H 2 O, [VO(oda)(phen)]·1.5H 2 O, [VO(ida)(H 2 O)]·H 2 O, [VO(ida)(bipy)]·2H 2 O and [VO(ida)(phen)]·2H 2 O have been used as the new catalysts for the oligomerization of 2-chloro-2-propen-1-ol. The oligomerization process undergoes very easy at room temperature and under atmospheric pressure. All products of the oligomerizations have been studied with the several analytical methods such as the matrix-assisted laser desorption/ionization–time-of-flight mass spectrometry (MALDI-TOF-MS), the nuclear magnetic resonance spectroscopy (NMR) and the thermogravimetric analysis (TGA) coupled with the analyzer of the infrared (IR) spectroscopy. The catalytic activities of the synthesized oxidovanadium(IV) complexes have been calculated which show that these complexes are the active catalysts in the 2-chloro-2-propen-1-ol oligomerization. [ABSTRACT FROM AUTHOR]

The iminodiacetate cobalt(II) complex is a new highly active catalyst for the 2-chloro-2-propen-1-ol oligomerization. The antioxidant activity of [Co(ida)(H 2 O) 2 ] against superoxide anion radical has been confirmed. It is very interesting to note that the NBT test results have shown that the tested complex is a stronger antioxidant than l -ascorbic acid. A coordination complex, [Co(ida)(H 2 O) 2 ] where ida denotes iminodiacetate, as a potential highly active catalyst was designed and obtained. To obtain a full structural characteristic, i.e. to determine the crystallographic details and the spatial structure of the crystals of the studied complex, X-ray analysis was carried out. [Co(ida)(H 2 O) 2 ] was investigated also by elementary analysis, IR spectrophotometry and MALDI-TOF-MS to get a full physicochemical characteristics. The stoichiometry of [Co(ida)(H 2 O) 2 ] in aqueous solutions was determined using the conductometric titrations. Consequently, the potentiometric titrations were performed to determine the thermodynamic stability of the title compound in aqueous solutions. Moreover, the antioxidant activity of [Co(ida)(H 2 O) 2 ] against superoxide anion radical has been examined by NBT test. The catalytic properties of the cobalt(II) complex, [Co(ida)(H 2 O) 2 ], were examined. It turned out that complex studied is a highly active catalyst for the 2-chloro-2-propen-1-ol oligomerization. It catalyzes the reaction of oligomerization in mild conditions: under normal pressure and at room temperature. The oligomerization reaction products were fully characterized by the following spectroscopic methods: IR, NMR, MALDI-TOF-MS. Furthermore, to investigate the thermal behavior of the obtained oligomer, the product of the oligomerization obtained using [Co(ida)(H 2 O) 2 ] as the catalyst was studied with the use of thermal analysis methods, i.e. DSC and TG. The catalytic activity of the title complex has also been calculated. [ABSTRACT FROM AUTHOR]

There are few literature reports on using precatalysts based on ruthenium(II/III) ions in the polymerization of olefins. Therefore, a new coordination compound was designed based on ruthenium(III) ion and 2-phenylpyridine. The resulting monocrystal was characterized by X-ray diffraction (XRD), solid-state (photo)IR spectroscopy, scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The new ruthenium(III) complex compound was used as a precatalyst in the oligomerization reactions of ethylene, 2-propen-1-ol, 2-chloro-2-propen-1-ol, 3-butene-2-ol and 2,3-dibromo-2-propen-1-ol with methylaluminoxane and ethylaluminium dichloride as activators. The catalytic activity of the newly discovered ruthenium(III) complex compound ranges from 159.5 (for 2-chloro-2-propen-1-ol) to 755.6 (for ethylene) g mmol -1 h -1 bar -1 , indicating that it is a chemical compound with high catalytic activity. In addition, the oligomerization reaction products were subjected to physicochemical characterization, using BET (Brunauer-Emmett-Teller isotherm), mass spectrometry (MALDI-TOF-MS), Fourier transform infrared (FT-IR) spectroscopy, NMR, TGA, differential scanning calorimetry (DSC), and the morphology of the porous polymeric materials was investigated by SEM. The distinguishing feature of the obtained precatalyst is its high catalytic activity under mild reaction conditions, a rare phenomenon. Compared with other precatalysts, it is the most active ruthenium(II/III) ion-based catalytic material used in oligo- and polymerization reactions of ethylene.

Estrogens function in numerous physiological processes including controlling brain cell growth and differentiation. 2-Methoxestradiol (2-ME2), a 17β-estradiol (E2) metabolite, is known for its anticancer effects as observed both in vivo and in vitro. 2-ME2 affects all actively dividing cells, including neurons. The study aimed to determine whether 2-ME2 is a potentially cancer-protective or rather neurodegenerative agent in a specific tissue culture model as well as a clinical setup. In this study, 2-ME2 activity was determined in a Parkinson's disease (PD) in vitro model based on the neuroblastoma SH-SY5Y cell line. The obtained results suggest that 2-ME2 generates nitro-oxidative stress and controls heat shock proteins (HSP), resulting in DNA strand breakage and apoptosis. On the one hand, it may affect intensely dividing cells preventing cancer development; however, on the other hand, this kind of activity within the central nervous system may promote neurodegenerative diseases like PD. Thus, the translational value of 2-ME2's neurotoxic activity in a PD in vitro model was also investigated. LC-MS/MS technique was used to evaluate estrogens and their derivatives, namely, hydroxy and methoxyestrogens, in PD patients' blood, whereas the stopped-flow method was used to assess hydrogen peroxide (H 2 O 2 ) levels. Methoxyestrogens and H 2 O 2 levels were increased in patients' blood as compared to control subjects, but hydoxyestrogens were simultaneously decreased. From the above, we suggest that the determination of plasma levels of methoxyestrogens and H 2 O 2 may be a novel PD biomarker. The presented research is the subject of the pending patent application "The use of hydrogen peroxide and 17β-estradiol and its metabolites as biomarkers in the diagnosis of neurodegenerative diseases," no. P.441360., (© 2023. The Author(s).)

Introduction: Solid lipid nanoparticles (SLN) have been considered lately as promising drug delivery system in treatment of many human diseases including cancers. We previously studied potential drug compounds that were effective inhibitors of PTP1B phosphatase - possible target for breast cancer treatment. Based on our studies, two complexes were selected for encapsulation into the SLNs, the compound 1 ([VO(dipic)(dmbipy)] · 2 H 2 O) and compound 2 ([VOO(dipic)](2-phepyH) · H 2 O). Here, we investigate the effect of encapsulation of those compounds on cell cytotoxicity against MDA-MB-231 breast cancer cell line. The study also included the stability evaluation of the obtained nanocarriers with incorporated active substances and characterization of their lipid matrix. Moreover, the cell cytotoxicity studies against the MDA-MB-231 breast cancer cell line in comparison and in combination with vincristine have been performed. Wound healing assay was carried out to observe cell migration rate., Methods: The properties of the SLNs such as particle size, zeta potential (ZP), and polydispersity index (PDI) were investigated. The morphology of SLNs was observed by scanning electron microscopy (SEM), while the crystallinity of the lipid particles was analyzed by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The cell cytotoxicity of complexes and their encapsulated forms was carried out against MDA-MB-231 breast cancer cell line using standard MTT protocols. The wound healing assay was performed using live imaging microscopy., Results: SLNs with a mean size of 160 ± 25 nm, a ZP of -34.00 ± 0.5, and a polydispersity index of 30 ± 5% were obtained. Encapsulated forms of compounds showed significantly higher cytotoxicity also in co-incubation with vincristine. Moreover, our research shows that the best compound was complex 2 encapsulated into lipid nanoparticles., Conclusion: We observed that encapsulation of studied complexes into SLNs increases their cell cytotoxicity against MDA-MB-231 cell line and enhanced the effect of vincristine., Competing Interests: The authors declare no conflicts of interest in this work., (© 2023 Kostrzewa et al.)

In this paper, a synthesis of two innovative coordination compounds, based on chromium(III) and cobalt(II) ions with N,O-donor ligands (nitrilotriacetate, dipicolinate) and 4-acetylpyridine, is reported. The obtained metal-organic compounds were structurally characterized using the single-crystal X-ray diffraction (XRD) method. The well-defined chromium(III) and cobalt(II) complexes were used as precatalysts in the oligomerization reaction of 2-chloro-2-propen-1-ol and 2-propen-1-ol with methylaluminoxane (MMAO) as an activator. The products of the oligomerization reaction were subjected to full physicochemical characteristics, i.e., time-of-flight mass spectrometry (MALDI-TOF-MS), TGA, and differential scanning calorimetry (DSC) methods. The catalytic activity of the precatalysts in both reactions was calculated and compared with other catalysts known in the literature.

The contemporary search for new catalysts for olefin oligomerization and polymerization is based on the study of coordinating compounds and/or organometallic compounds as post-metallocene catalysts. However known catalysts are suffered by many flaws, among others unsatisfactory activity, requirement of high pressure or instability at high temperatures. In this paper, we present a new catalyst i.e. the crystalline complex compound possesing high catalytic activity in the oligomerization of olefins, such as 2-chloro-2-propen-1-ol and ethylene under very mild conditions (room temperature, 0.12 bar for ethylene oligomerization, atmospheric pressure for 2-chloro-2-propen-1-ol oligomerization). New material-Cat-CrNP ([nitrilotriacetato-1,10-phenanthroline]chromium(III) tetrahydrate) has been obtained as crystalline form of the nitrilotriacetate complex compound of chromium(III) with 1,10-phenanthroline and characterized in terms of its crystal structure by the XRD method and by multi-analytical investigations towards its physicochemical propeties The yield of catalytic oligomerization over Cat-CrNP reached to 213.92 g · mmol -1 · h -1 · bar -1 and 3232 g · mmol -1 · h -1 · bar -1 for the 2-chloro-2-propen-1-ol and ethylene, respectively. Furthemore, the synthesis of Cat-CrNP is cheap, easy to perform and solvents used during preparation are environmentally friendly., (© 2021. The Author(s).)

The report focuses on the new precatalysts for ethylene oligomerization. The five chromium(III) complex compounds containing the following ligands: dipicolinate anion, oxalate anion, 5-aminopyridine-2-carboxylate anion, 2,2'-bipyridine and 4,4'-dimethoxy-2,2'-bipyridine have been examined towards catalytic activity for ethylene oligomerization. The chromium(III) complexes have been activated by modified methylaluminoxane. The obtained oligomers have been investigated by MALDI-TOF-MS, thermal analysis and infrared spectroscopy. The results revealed that the examined chromium(III) complexes are highly active catalysts for ethylene oligomerization. The values of catalytic activities of the examined complexes are in the range 1860 - 3798 g∙mmol -1 ∙h -1 ∙bar -1 .

2-methoxyestradiol (2-ME) is a physiological anticancer compound, metabolite of 17β-estradiol. Previously, our group evidenced that from mechanistic point of view one of anticancer mechanisms of action of 2-ME is specific induction and nuclear hijacking of neuronal nitric oxide synthase (nNOS), resulting in local generation of nitro-oxidative stress and finally, cancer cell death. The current study aims to establish the substantial mechanism of generation of reactive nitrogen species by 2-ME. We further achieved to identify the specific reactive nitrogen species involved in DNA-damaging mechanism of 2-ME. The study was performed using metastatic osteosarcoma 143B cells. We detected the release of biologically active (free) nitric oxide ( • NO) with concurrent measurements of peroxynitrite (ONOO - ) in real time in a single cell of 143B cell line by using • NO/ONOO - sensitive microsensors after stimulation with calcium ionophore. Detection of nitrogen dioxide ( • NO 2 ) and determination of chemical rate constants were carried out by a stopped-flow technique. The affinity of reactive nitrogen species toward the guanine base of DNA was evaluated by density functional theory calculations. Expression and localization of nuclear factor NF-kB was determined using imaging cytometry, while cell viability assay was evaluated by MTT assay. Herein, we presented that 2-ME triggers pro-apoptotic signalling cascade by increasing cellular reactive nitrogen species overproduction - a result of enzymatic uncoupling of increased nNOS protein levels. In particular, we proved that ONOO - and • NO 2 directly formed from peroxynitrous acid (ONOOH) and/or by auto-oxidation of • NO, are inducers of DNA damage in anticancer mechanism of 2-ME. Specifically, the affinity of reactive nitrogen species toward the guanine base of DNA, evaluated by density functional theory calculations, decreased in the order: ONOOH > ONOO -  >  • NO 2  >  • NO. Therefore, we propose to consider the specific inducers of nNOS as an effective tool in the field of chemotherapy., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)

Environmental contaminants, such as heavy metals, nanomaterials, and pesticides, induce the formation of reactive oxygen and nitrogen species (RONS). Plants interact closely with the atmosphere, water, and soil, and consequently RONS intensely affect their biochemistry. For the past 30 years researchers have thoroughly examined the role of RONS in plant organisms and oxidative modifications to cellular components. Hydrogen peroxide, superoxide anion, nitrogen(II) oxide, and hydroxyl radicals have been found to take part in many metabolic pathways. In this review the various aspects of the oxidative stress induced by environmental contamination are described based on an analysis of literature. The review reinforces the contention that RONS play a dual role, that is, both a deleterious and a beneficial one, in plants. Environmental contamination affects human health, also, and so we have additionally described the impact of RONS on the coupled human - environment system., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

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 H 2 O 2 .

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)(H 2 O)]H 2 O. The X-ray measurements have revealed that the compound comprises the discrete mononuclear [VO(nta)(H 2 O)] - coordination ion that can be rarely found among other known compounds containing nitrilotriacetate oxidovanadium(IV) moieties. The antitumor activity of [bpyH][VO(nta)(H 2 O)]H 2 O and its phenanthroline analogue, [phenH][VO(nta)(H 2 O)](H 2 O) 0.5 , towards human osteosarcoma cell lines (MG-63 and HOS) has been assessed (the LDH and BrdU tests) and referred to cis-Pt(NH 3 ) 2 Cl 2 (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)(H 2 O)] - containing coordination compounds can be considered as possible antitumor agents in the osteosarcoma model of bone-related cells in culture.

The fluorescence quenching of 7-amino-4-methylcoumarin by different TEMPO derivatives was studied in aqueous solutions with the use of steady-state, time-resolved fluorescence spectroscopy as well as UV-VIS absorption spectroscopy methods. In order to distinguish each TEMPO derivative from the others and to understand the mechanism of quenching, the absorption and fluorescence emission spectra as well as decays of the fluorescence of 7-amino-4-methylcoumarin were registered as a function of each TEMPO derivative concentration. There were no deviations from a linearity in the Stern-Volmer plots (determined from both, steady-state and time-resolved measurements). The fluorescence quenching mechanism was found to be entirely collisional, what was additionally confirmed by the registration of Stern-Volmer plots at 5 temperatures ranging from 15 to 55°C. Based on theoretical calculations of molecular radii and ionization potentials of all TEMPO derivatives the mechanism of electron transfer was rejected. The fluorescence quenching which was being studied seems to be diffusion-limited and caused by the increase of non-radiative processes, such as an internal conversion and an intersystem crossing. The Stern-Volmer quenching constants and bimolecular quenching constants were determined at the room temperature for all TEMPO derivatives studied. Among all TEMPO derivatives studied TEMPO-4-amino-4-carboxylic acid (TOAC) was found to be the most effective quencher of 7-amino-4-methylcoumarin fluorescence (kq for TOAC was approximately 1.5 higher than kq for other TEMPO compounds studied). The findings demonstrate the possibility of developing an analytical method for the quantitative determination of TOAC, which incorporation into membrane proteins may provide a direct detection of peptide backbone dynamics., (Copyright © 2014 Elsevier B.V. All rights reserved.)