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Search results for: PNP PINCER LIGAND
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Structural analysis and physico-chemical characterization of mononuclear manganese(II) and polynuclear copper(II) complexes with pyridine-based alcohol
PublicationTwo novel manganese(II) and copper(II) complexes, mononuclear [Mn(H2O)2(2-(CH2)2OHpy)2](NO3)2 (1) and polynuclear [Cu(SO4)(2-(CH2)2OHpy)2]n (2), based on 2-(hydroxyethyl)pyridine (2-(CH2)2OHpy) were synthesised and fully characterised using X-ray structure analysis as well as spectroscopic, magnetic and thermal methods. Both central metal ions Mn(1) and Cu(1) are coordinated by two N,O-donor 2-(CH2)2OHpy ligands and possess an...
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Electronic States of Tris(bipyridine) Ruthenium(II) Complexes in Neat Solid Films Investigated by Electroabsorption Spectroscopy
PublicationWe present the electric field-induced absorption (electroabsorption, EA) spectra of the solid neat films of tris(bipyridine) Ru(II) complexes, which were recently functionalized in our group as photosensitizers in dye-sensitized solar cells, and we compare them with the results obtained for an archetypal [Ru(bpy)3]2+ ion (RBY). We argue that it is difficult to establish a unique set of molecular parameter values by discrete parametrization...
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Biomimetic zinc(II) and cobalt(II) complexes with tri-tert-butoxysilanethiolate and imidazole ligands - structural and spectroscopic studies.
PublicationNowe heteroleptyczne kompleksy tri-tert-butoksysilanotiolanowe Zn(II) i Co(II) z dodatkowymi ligandami imidazolowymi zostały scharakteryzowane strukturalnie i spektralnie. Otrzymano kompleksy o różnych centrach koordynacji w zależności od ligandów imidazolowych. Dla jonów Co(II)otrzymano kompleksy o rdzeniach: NOS2 (z cząsteczką metanolu jako O-donorowy ligand) w związku 2', NO2S2 w 2'', N2S2 w 1, zaś w przypadku jonów Zn(II):...
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Intercalation complex of imidazoacridinone C-1311, a potential anticancer drug, with DNA helix d(CGATCG)2: stereostructural studies by 2D NMR spectroscopy.
PublicationImidazoacridinone C-1311 (Symadex®) is a powerful antitumor agent, which successfully made its way through the Phase I clinical trials and has been recommended for Phase II few a years ago. It has been shown experimentally that during the initial stage of its action C-1311 forms a relatively stable intercalation complex with DNA, yet it has shown no base-sequence specificity while binding to DNA. In this paper, the d(CGATCG)2:C-1311...
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Structural and dynamic changes adopted by EmrE, multidrug transporter protein—Studies by molecular dynamics simulation
PublicationEmrE protein transports positively charged aromatic drugs (xenobiotics) in exchange for two protons and thus provides bacteria resistance to variety of drugs. In order to understand how this protein may recognize ligands, the monomer and asymmetric apo-form of the EmrE dimer embedded in a heterogeneous phospholipid (POPE + POPG) membrane were studied by molecular dynamics simulations. Dimer is regarded as a functional form of the...
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Geometry optimization of steroid sulfatase inhibitors - the influence on the free binding energy with STS
PublicationIn the paper we review the application of two techniques (molecular mechanics and quantum mechanics) to study the influence of geometry optimization of the steroid sulfatase inhibitors on the values of descriptors coded their chemical structure and their free binding energy with the STS protein. We selected 22 STS-inhibitors and compared their structures optimized with MM+, PM7 and DFT B3LYP/6–31++G* approaches considering separately...
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Optimization of vortex-assisted supramolecular solvent-based liquid liquid microextraction for the determination of mercury in real water and food samples
PublicationA novel method was developed for sample preparation for spectrophotometric determination of Hg(II) in water and food samples. The method was based on vortex-assisted supramolecular solvent-assisted liquid-liquid microextraction (VA-SUPRASs-LLME). Analytical parameters such as pH, chelating agent, solvent type and volume, vortex time and salting out effect were optimized. Surface and normal probability plots were drawn for the variables...
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Ultrasensitive electrochemical determination of the cancer biomarker protein sPD-L1 based on a BMS-8-modified gold electrode
PublicationThis work describes the modification of a gold electrode with the BMS-8 compound that interacts with the Programmed Death-Ligand 1 (PD-L1), an immune checkpoint protein. The results show that we can confirm the presence of the sPD-L1 in the concentration range of 10−18 to 10−8 M using electrochemical impedance spectroscopy (EIS) with a limit of detection (LOD) of 1.87 × 10−14 M for PD-L1 (S/N = 3.3) and at a concentration of 10−14...
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Determination of long-chain aldehydes using a novel quartz crystal microbalance sensor based on a biomimetic peptide
PublicationThere is an increasingly popular trend aimed at improvement of fundamental metrological parameters of sensors via implementation of materials mimicking biological olfactory systems. This study presents investigation on usefulness of the peptide mimicking HarmOBP7 region as a receptor element of the piezoelectric sensor for selective analysis of long-chain aldehydes. Identification of odorant binding proteins creates new possibilities...
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New pathways for functionalization of phosphorus ligands
PublicationThe presented dissertation consistsof two main partsand focuses on the synthesis and characterization of new low-valent phosphorus compounds. Thesestudies have already been fully described in three JCR-journals. The first partdescribes the utilization ofselectedphosphanylphosphinidene transition metal complexes as a source of diversified phosphorus ligands. For thispurposethree complexes...
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Molecular mechanism and energetics of coupling between substrate binding and product release in the F 1 -ATPase catalytic cycle
PublicationF1-ATPase is a motor protein that couples the rotation of its rotary γ subunit with ATP synthesis or hydrolysis. Single-molecule experiments indicate that nucleotide binding and release events occur almost simultaneously during the synthesis cycle, allowing the energy gain due to spontaneous binding of ADP to one catalytic β subunit to be directly harnessed for driving the release of ATP from another rather than being dissipated...
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N-doped carbon nanospheres as selective fluorescent probes for mercury detection in contaminated aqueous media: chemistry, fluorescence probing, cell line patterning, and liver tissue interaction
PublicationA precise nano-scale biosensor was developed here to detect Hg2+ in aqueous media. Nitrogen-doped carbon nanospheres (NCS) created from the pyrolysis of melamine–formaldehyde resin were characterized by FESEM, XRD, Raman spectra, EDS, PL, UV–vis spectra, and N2 adsorption–desorption, and were used as a highly selective and sensitive probe for detecting Hg2+ in aqueous media. The sensitivity of NCS to Hg2+ was evaluated by photoluminescence...
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Analiza strukturalna silanotiolanów : wpływ centrów kwasowych na zmiany w układzie wiązań SI-O-C oraz SI-S grupy sialkoksysilanotiolanowej w ciele stałym / J. Chojnacki.
PublicationW pracy przedstawiono wyniki badań strukturalnych silanotiolanów metali. Wyniki pochodzące z rentgenowskiej analizy strukturalnej zostały zinterpretowane w oparciu o rezultaty obliczeń kwantowo-mechanicznych. Wyznaczono 46 nowych struktur rentgenowskich silanotiolanów i przeanalizowano je łącznie z wynikami badań strukturalnych innych autorów. Zebrano i usystematyzowano wyniki rentgenowskiej analizy strukturalnej dla wszystkich...
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Density functional theory calculations on entire proteins for free energies of binding: Application to a model polar binding site
PublicationIn drug optimization calculations, the molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) method can be used to compute free energies of binding of ligands to proteins. The method involves the evaluation of the energy of configurations in an implicit solvent model. One source of errors is the force field used, which can potentially lead to large errors due to the restrictions in accuracy imposed by its empirical nature....
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Mechanochemical Energy Transduction during the Main Rotary Step in the Synthesis Cycle of F1-ATPase
PublicationF1-ATPase is a highly efficient molecular motor that can synthesize ATP driven by a mechanical torque. Its ability to function reversibly in either direction requires tight mechanochemical coupling between the catalytic domain and the rotating central shaft, as well as temporal control of substrate binding and product release. Despite great efforts and significant progress, the molecular details of this synchronized and fine-tuned...
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The role of glucuronidation in drug resistance
PublicationThe final therapeutic effect of a drug candidate, which is directed to a specific molecular target strongly depends on its absorption, distribution, metabolism and excretion (ADME). The disruption of at least one element of ADME may result in serious drug resistance. In this work we described the role of one element of this resistance: phase II metabolism with UDP-glucuronosyltransferases (UGTs). UGT function is the transformation...
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Crystal and electronic structures of Ni(II) silanethiolates containing flexible diamine ligands
PublicationFive nickel(II) complexes containing aliphatic diamines and tri-tert-butoxysilanethiolate ligand have been synthesized for the purpose of studying their structural, spectral (IR, UV–Vis, HF EPR) and thermal properties. Complexes (1)–(5) have been prepared in high yield by reactions of [Ni{SSi(OtBu)3}2(NH3)(H2O)] with 1.3-propanediamine (L1), 1,6-hexanediamine (L2), or 1,7-heptanediamine (L3). The X-ray structures were determined...
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Methods for Elucidation of DNA-Anticancer Drug Interactions and Their Applications in the Development of New Drugs
PublicationDNA damaging agents including anthracyclines, camptothecins and platinum drugs are among most frequently used drugs in the chemotherapeutic routine. Due to their relatively low selectivity for cancer cells, administration is associated with adverse side effects, whereas the inherent genotoxicity of these drugs is associated with risk of developing secondary cancers. Development of new drugs, which could be spared of these drawbacks...
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DL_MG: A Parallel Multigrid Poisson and Poisson–Boltzmann Solver for Electronic Structure Calculations in Vacuum and Solution
PublicationThe solution of the Poisson equation is a crucial step in electronic structure calculations, yielding the electrostatic potential -- a key component of the quantum mechanical Hamiltonian. In recent decades, theoretical advances and increases in computer performance have made it possible to simulate the electronic structure of extended systems in complex environments. This requires the solution of more complicated variants of the...
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Carboxylic acids as efficient corrosion inhibitors of aluminium alloys in alkaline media
PublicationThe efficiency of AA5754 aluminium alloy corrosion inhibition achieved with maleic, malic, succinic, tartaric, citric, tricarballylic acids and serine in alkaline environment (pH 11) was examined. Selected corrosion inhibitors are characterized by different numbers and distribution of carbonyl and hydroxyl groups within their molecules. We have proposed and verified a novel approach for determining the adsorption isotherms based...
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A comparison of structural and luminescence properties of lead(II) coordination polymers with isomeric thiophenecarboxylate ligands
PublicationTwo new lead(II) coordination polymers with isomeric thiophenecarboxylates, namely [Pb(2tpCOO)2]n (1) and [Pb(3tpCOO)2(H2O)]n (2) (2tpCOO− = thiophene-2-carboxylate, 3tpCOO− = thiophene-3-carboxylate), were synthesized and characterized. Single crystal X-ray crystallography revealed a distorted pentagonal pyramidal geometry {PbO6} around Pb in 1 and a distorted dodecahedral geometry {PbO8} in 2. The distortion derived from the...
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Molecular basis of the osmolyte effect on protein stability: a lesson from the mechanical unfolding of lysozyme
PublicationOsmolytes are a class of small organic molecules that shift the protein folding equilibrium. For this reason, they are accumulated by organisms under environmental stress, and find applications in biotechnology where proteins need to be stabilized or dissolved. However, despite years of research, debate continues over the exact mechanisms underpinning the stabilizing and denaturing effect of osmolytes. Here, we simulated the mechanical...
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Homoleptic mono-, di-, and tetra-iron complexes featuring phosphido ligands: a synthetic, structural, and spectroscopic study
PublicationWe report the first series of homoleptic phosphido iron complexes synthesized by treating either the β-diketiminato complex [(Dippnacnac)FeCl2Li(dme)2] (Dippnacnac = HC[(CMe)N(C6H3-2,6-iPr2)]2) or [FeBr2(thf )2] with an excess of phosphides R2PLi (R = tBu, tBuPh, Cy, iPr). Reaction outcomes depend strongly on the bulkiness of the phosphido ligands. The use of tBu2PLi precursor led to an anionic diiron complex 1 encompassing a planar...
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Termodynamika niekowalencyjnego oddziaływania małocząsteczkowych ligandów z dna
PublicationKwasy nukleinowe są jednym z głównych celów biologicznych dla wielu antybiotyków oraz leków przeciwnowotworowych i przeciwwirusowych. Podczas tworzenia nowych farmaceutyków ważna jest dokładna wiedza na temat sposobu wiązania się leku do DNA. Oddziaływanie ligand-DNA można podzielić na dwie grupy: 1. wiązanie kowalencyjne, które często prowadzi do utworzenie trwałych wiązań pomiędzy nićmi DNA, 2. fizykochemiczne wiązanie, które...
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Recent Advances in Polymer Nanocomposites: Unveiling the Frontier of Shape Memory and Self-Healing Properties—A Comprehensive Review
PublicationShape memory and self-healing polymer nanocomposites have attracted considerable attention due to their modifiable properties and promising applications. The incorporation of nanomaterials (polypyrrole, carboxyl methyl cellulose, carbon nanotubes, titania nanotubes, graphene, graphene oxide, mesoporous silica) into these polymers has significantly enhanced their performance, opening up new avenues for diverse applications. The...
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Solvothermal growth of {0 0 1} exposed anatase nanosheets and their ability to mineralize organic pollutants. The effect of alcohol type and content on the nucleation and growth of TiO2 nanostructures
PublicationHerein, the series of {0 0 1} exposed anatase nanosheets from HF-assisted solvothermal growth synthesis were obtained. The two-dimensional TiO2 were characterized, including both bulk (XRD, DR-UV–Vis, Mott-Schottky) and surface characteristics (N2 sorption, XPS, SEM) with experimental results compiled with Density Functional Theory (DFT) calculations. The effect of alcohol amount and type was studied, demonstrating the crucial...
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Corrosion Inhibition Mechanism and Efficiency Differentiation of Dihydroxybenzene Isomers Towards Aluminum Alloy 5754 in Alkaline Media
PublicationThe selection of efficient corrosion inhibitors requires detailed knowledge regarding the interaction mechanism, which depends on the type and amount of functional groups within the inhibitor molecule. The position of functional groups between different isomers is often overlooked, but is no less important, since factors like steric hinderance may significantly affect the adsorption mechanism. In this study, we have presented how...
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Assestment of the anti-cancer activity of the copper complexes with imidazole and pivalato ligands
PublicationDespite the development of science and technology progress so far there have not been found effective drugs for cancer. Many coordination compounds were investigated due to their antitumor potential. The most known cis-diamminedichloroplatinum(II) is used as anti-cancer therapeutic agent. The copper complexes are the coordination compounds possessing anti-tumour properties. Their capability to kill cancer cells is mainly linked...
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Experimental and theoretical investigation of the reactivity of [(BDI*)Ti(Cl){η2-P(SiMe3)-PiPr2}] towards selected ketones
PublicationIn this work, we report a new type of reactivity of [(BDI*)Ti(Cl){η2-P(SiMe3)-PiPr2}] (1) towards ketones (BDI* = 2,6-diisopropylphenyl-β-methyldiketiminate ligand). In the reaction of 1 with acetone, cyclopentanone or cyclohexanone, a ketone moiety is inserted into Ti–Pphosphanyl or Ti–Pphosphido bonds to form complexes with a new C–P–P moiety, providing [(BDI*)Ti(Cl){η2-P(SiMe3)-PiPr2-C(Me)2O}] (2a), [(BDI*)Ti(Cl){η2-OC(Me)2P(SiMe3)-PiPr2}]...
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Muramyl dipeptide-based analogs as potential anticancer compounds: Strategies to improve selectivity, biocompatibility, and efficiency
PublicationAccording to the WHO, cancer is the second leading cause of death in the world. This is an important global problem and a major challenge for researchers who have been trying to find an effective anticancer therapy. A large number of newly discovered compounds do not exert selective cytotoxic activity against tumorigenic cells and have too many side effects. Therefore, research on muramyl dipeptide (MDP) analogs has attracted interest...
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Synthesis of compounds with C-P-P and C=P-P bond systems based on the phospha-Wittig reaction
PublicationA reactivity study of a β-diketiminate titanium(III) phosphanylphosphido complex [MeNacNacTi(Cl){η2-P(SiMe3)-PtBu2}] (1) towards ketones such as benzophenone, 9-fluorenone, acetophenone, cyclopentanone, cyclohexanone and cycloheptanone is reported. The reactions of 1 with aromatic ketones (without α-protons) directly lead to the Ti(III) complex [MeNacNacTi(μ2-Cl)(OSiMe3)] (5) as well as Ti(IV) complexes with the pinacol condensation...
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Green porous benzamide-like nanomembranes for hazardous cations detection, separation, and concentration adjustment
PublicationGreen biomaterials play a crucial role in the diagnosis and treatment of diseases as well as health-related problem-solving. Typically, biocompatibility, biodegradability, and mechanical strength are requirements centered on biomaterial engineering. However, in-hospital therapeutics require an elaborated synthesis of hybrid and complex nanomaterials capable of mimicking cellular behavior. Accumulation of hazardous cations like...
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Topological behavior mimicking ethylene–hexene copolymers using branched lactones and macrolactones
PublicationPolyolefins are of paramount importance in the world of polymers due to their technological and economic potential.1 However, their nonpolar character significantly restricts the compatibility and adhesion properties, which consequently limits their versatility. Moreover, an intensified demand for materials from renewable resources can also become a problematic venture for the current polyolefin industry.2 Although Braskem and...
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Development of biocompatible iron oxide-silicon oxide core-shell nanoparticles as subcellular delivery platform for glucosamine-6-phosphate synthase inhibitors
PublicationIn order to develop the preparation of iron oxide-silica coreshell nanoparticles (CSNPs), thesis deeply explores the cetyltrimethylammonium (CTA+) directed silica coating methods of the oleic-acid capped iron oxide nanoparticles (OA-IONPs) initialized under near-neutral pH conditions. It is demonstrated that the initial alkaline hydrolysis of ethyl acetate in the presence of CTA+ and OA-IONPs induces an unusual ligand exchange...
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Baktericyna o aktywności gronkowcobójczej wytwarzana przez Staphylococcus xylosus - identyfikacja, oczyszczanie oraz wstępna charakterystyka
PublicationCelem badań prowadzonych w ramach realizacji niniejszej pracy była identyfikacja szczepów bakterii z rodzaju Staphylococcus produkujących substancje o działaniu przeciwbakteryjnym, w tym szczególnie bakteriocyny. W trakcie badań przesiewowych, których przedmiotem było 206 szczepów z kolekcji Katedry Technologii Leków i Biochemii Politechniki Gdaoskiej z gatunków Staphylococcus aureus, Staphylococcus epidermidis oraz Staphylococcus...
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Development of Biocompatible Fe3O4@SiO2 Nanoparticles as Subcellular Delivery Platform for Glucosamine-6-phosphate Synthase Inhibitors
PublicationNumerous inhibitors of glucoseamine-6-phophate synthase (GlcN-6-P), the enzyme responsible from catalysis of the first step of metabolic pathway leading to metabolism 5’-diphospho-N-acetyl-D- glucosamine, were reported as effective agents for inhibiting the growth of various fungal pathogens. Among the reported inhibitors,...