A series of new VO(IV) complexes of tetradentate N2O2 Schiff base ligands (L(1)-L(4)), were synthesized and characterized by FT-IR, UV-vis and elemental analysis. The structure of the complex VOL(1)⋅DMF was also investigated by X-ray crystallography which revealed a vanadyl center with distorted octahedral coordination where the 2-aza and 2-oxo coordinating sites of the ligand were perpendicular to the "-yl" oxygen. The electrochemical properties of the vanadyl complexes were investigated by cyclic voltammetry. A good correlation was observed between the oxidation potentials and the electron withdrawing character of the substituents on the Schiff base ligands, showing the following trend: MeO5-H>5-Br>5-Cl. Furthermore, the kinetic parameters of thermal decomposition were calculated by using the Coats-Redfern equation. According to the Coats-Redfern plots the kinetics of thermal decomposition of studied complexes is of the first-order in all stages, the free energy of activation for each following stage is larger than the previous one and the complexes have good thermal stability. The preparation of VOL(1)⋅DMF yielded also another compound, one kind of vanadium oxide [VO]X, with different habitus of crystals, (platelet instead of prisma) and without L(1) ligand, consisting of a V10O28 cage, diaminium moiety and dimethylamonium as a counter ions. Because its crystal structure was also new, we reported it along with the targeted complex.

• Klíčová slova
• Electrochemistry, Kinetics of thermal decomposition, Oxovanadium(IV) complexes, Schiff base,
• MeSH
• elektrochemie MeSH
• kinetika MeSH
• krystalografie rentgenová MeSH
• molekulární modely MeSH
• Schiffovy báze chemie   MeSH
• spektroskopie infračervená s Fourierovou transformací MeSH
• termodynamika MeSH
• vanadáty chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• oxovanadium IV MeSH Prohlížeč
• Schiffovy báze MeSH
• vanadáty MeSH

The scarcity of efficient force fields to describe metal complexes may be a problem for new advances in medicinal chemistry. Thus, the development of force fields for these compounds can be valuable for the scientific community, especially when it comes to molecules that show interesting outputs regarding potential treating of diseases. Vanadium complexes, for instance, have shown promising results towards therapeutics of Alzheimer's Disease, most notably the bis(maltolato)oxovanadium (IV). Therefore, the mainly goal of this work is to develop and validate a new set of parameters for this vanadium complex from a minimum energy structure, obtained by DFT calculations, where great results of the new force field are found when confronted with experimental and quantum reference values. Moreover, the new force field showed to be quite effective to describe the molecule of under study whilst GAFF could not describe it effectively. In addition, a case study points out hydrogen bonds in the vanadium complex-PTP1B system.

• Klíčová slova
• AMBER Force field, Alzheimer's disease, Docking, Molecular dynamics, Vanadium complex,
• MeSH
• Alzheimerova nemoc * farmakoterapie   MeSH
• komplexní sloučeniny * MeSH
• lidé MeSH
• vanad chemie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• komplexní sloučeniny * MeSH
• vanad MeSH

Solid complexes of D-galacturonic acid (GalA) with cobalt(II), copper(II), nickel(II) and oxovanadium(IV) (1-4) were prepared and characterised. The metal-to-ligand molar ratio was 1:2 for complexes 1-3 and 1:1 for complex 4. The alpha- and beta-anomers of GalA were detected in all the complexes in solid state and in solutions. An addition of small amounts of the paramagnetic complexes to the D2O solution of pure ligand led to NMR line broadening of some 1H and 13C nuclei. This broadening was sensitive to the anomeric state of GalA in the case of complexes 1 and 4. NMR and vibrational spectroscopic data indicate the formation of carboxylate complexes of all the cations, while noncarboxylic oxygens are also involved into the metal bonding in some cases. VCD spectra of complexes 1-4 in D2O and Me2SO-d6 solutions confirm that GalA carboxylic group may participate in the formation of optically active species around the metal cation. Possible ways of GalA coordination by metal cations of this study were proposed and discussed.

• MeSH
• kationty dvojmocné chemie   MeSH
• kyseliny hexuronové chemie   MeSH
• magnetická rezonanční spektroskopie MeSH
• molekulární struktura MeSH
• roztoky MeSH
• těžké kovy chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• galacturonic acid MeSH Prohlížeč
• kationty dvojmocné MeSH
• kyseliny hexuronové MeSH
• roztoky MeSH
• těžké kovy MeSH

A large part of the world's population is affected by Alzheimer's disease (AD) and diabetes mellitus type 2, which cause both social and economic impacts. These two conditions are associated with one protein, AMPK. Studies have shown that vanadium complexes, such as bis(N',N'-dimethylbiguanidato)-oxovanadium(IV), VO(metf)2·H2O, are potential agents against AD. A crucial step in drug design studies is obtaining information about the structure and interaction of these complexes with the biological targets involved in the process through molecular dynamics (MD) simulations. However, MD simulations depend on the choice of a good force field that could present reliable results. Moreover, general force fields are not efficient for describing the properties of metal complexes, and a VO(metf)2·H2O-specific force field does not yet exist; thus, the proper development of a parameter set is necessary. Furthermore, this investigation is essential and relevant given the importance for both the scientific community and the population that is affected by this neurodegenerative disease. Therefore, the present work aims to develop and validate the AMBER force field parameters for VO(metf)2·H2O since the literature lacks such information on metal complexes and investigate through classical molecular dynamics the interactions made by the complex with the protein. The proposed force field proved to be effective for describing the vanadium complex (VC), supported by different analyses and validations. Moreover, it had a great performance when compared to the general AMBER force field. Beyond that, MD findings provided an in-depth perspective of vanadium complex-protein interactions that should be taken into consideration in future studies.

• MeSH
• Alzheimerova nemoc * farmakoterapie   MeSH
• komplexní sloučeniny * terapeutické užití   MeSH
• lidé MeSH
• neurodegenerativní nemoci * MeSH
• proteinkinasy aktivované AMP chemie   MeSH
• simulace molekulární dynamiky MeSH
• vanad chemie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• komplexní sloučeniny * MeSH
• proteinkinasy aktivované AMP MeSH
• vanad MeSH