We report on the translational dynamics of ions in fluorine-free gels prepared using a flexible lithium salt comprising a (2-methoxyethoxy)acetate (MEA) anion, ethylene glycol (EG) and polyvinyl alcohol (PVA). 1H and 7Li Pulsed-Field-Gradient (PFG) NMR were performed on thin (0.2 mm) and thick (0.7 mm) films of the gels at different orientations with respect to the external magnetic field and magnetic gradients. Two diffusional decay components are observed: a slow mode linked to PVA network oscillations and a fast mode from mobile ions with diffusivities up to three orders of magnitude higher. It is found that Li+ cations are not directly bound to the network, but they have a distribution of diffusion coefficients. A similar trend is observed for diffusivities of the organic anion, (MEA), revealed from the fast component of diffusional decays in 1H PFG NMR. The diffusivities of ions have an orientational dependence on the films and are higher in thick films in the normal orientation with respect to the external magnetic field. The temperature dependence of Li+ diffusivities does follow the Arrhenius behavior. An interesting observation is that an elongation of the gel films by stretching reduces Li+ cation diffusivities and leads to broadening of the 7Li NMR resonance lines, suggesting that the transport properties of the ions are strongly governed by the structural constraints and internal stresses in the gel network.

Doxorubicin (DOX) is a prevalent anticancer agent; however, it is unfortunately characterized by high cardiotoxicity, myelosuppression, and multiple other side effects. To overcome DOX limitations, two novel pyridoxine-derived doxorubicin derivatives were synthesized (DOX-1 and DOX-2). In the present study, their antitumor activity and mechanism of action were investigated. Of these two compounds, DOX-2, in which the pyridoxine fragment is attached to the doxorubicin molecule via a C3 linker, revealed higher selectivity against specific cancer cell types compared to doxorubicin and a promising safety profile for conditionally normal cells. However, the compound with a C1 linker (DOX-1) was not characterized by selectivity of antitumor action. It was revealed that DOX-2 obstructs cell cycle progression, induces apoptosis via the mitochondrial pathway without the development of necrosis, and showcases antioxidant capabilities, underlining its cell-regulatory roles. In contrast to doxorubicin’s DNA-centric mechanism, DOX-2 does not interact with nuclear DNA. Given these findings, DOX-2 presents a new promising direction in cancer therapeutics, which is deserving of further in vivo exploration.

An approach to the synthesis of pyridoxine azo derivatives based on aminophenols was developed. 52 new pyridoxine derivatives were synthesized. An in vitro study of antiglycation properties showed that most of the prepared pyridoxine azo derivatives (IC50 = 10–191 μM) significantly exceed the phase I-II clinical trials drugs aminoguanidine (IC50 = 526 μM) and pyridoxamine (IC50 = 834 μM) in their activity. Some of the obtained compounds also have high antioxidant activity and effectively inhibit lipid peroxidation.

Several pyridoxine azo derivatives have been synthesized and their in vitro antiglycation activity has been studied. It has been found that the synthesized compounds are more active in terms of IC 50 than aminoguanidine (by factors of 6–21) and pyridoxamine (by factors of 1.8–5.6). The in vivo study of acute toxicity of the most potent compound has shown their safety (LD 50 > 2000 mg/kg).

Благодаря уникальным электронным и оптическим свойствам малослойный черный фосфор (МЧФ) является перспективным двумерным материалом для применения в различных областях химии и физики. Химическая функционализация поверхности МЧФ является эффективной стратегией для улучшения стабильности к окислению, а также для настройки и придания новых свойств фосфорному материалу. В данной работе предложен подход к иммобилизации комплекса [NiBr2(phen)] (где phen – 1,10-фенантролин) на поверхности МЧФ путем ковалентной функционализации МЧФ 1,10-фенантролином и последующим образованием комплекса с NiBr2. Полученные фосфорсодержащие материалы на основе МЧФ, функционализированного комплексом [NiBr2(phen)] охарактеризованы комплексом физико-химических методов, включая просвечивающую электронную микроскопию (ПЭМ), атомно-силовую микроскопию (АСМ), а также твердотельную ЯМР-, ЭДС-, КР- и ИК-спектроскопию.

This review paper presents the results of a study conducted using nuclear magnetic resonance (NMR) methods to investigate the dynamic behaviour of ionic liquid-based compositions in micrometre-spaced confinement. Ethylammonium nitrate (EAN) and other ionic liquid (IL) systems with nitrate anion in glass or quartz spaced confinement demonstrate anomalous cation dynamics that differ from those observed in bulk and in nano-confinement. It was demonstrated that the principal axis of the nitrate anion exhibits preferential orientation to the surface, akin to that in liquid crystals. It was shown that the cation translational mobility reversibly changes during exposure to a static magnetic field. This phenomenon was interpreted as a result of intermolecular structure transformations occurring in the confined ILs. The mechanisms of these transformations were discussed.

A 2D material few-layer black phosphorus (FLBP) has promising applications in various fields of chemistry and physics due to its unique electronic and optical properties. Chemical functionalization of the FLBP surface is an effective strategy for improving the oxidative stability of the material, tuning its intrinsic properties or endowing it with new properties. The present work proposes an approach to the immobilization of the [NiBr2(phen)] complex (phen = 1, 10-phenanthroline) on the FLBP surface via covalent functionalization of FLBP with 1,10-phenanthroline and subsequent complexation with NiBr2. The obtained FLBP-based materials functionalized by the [NiBr2(phen)] complex were characterized by a set of physicochemical methods such as transmission electron microscopy, atomic force microscopy, solid-state NMR, energy-dispersive spectroscopy, Raman spectroscopy, and IR spectroscopy.

133 Cs NMR was employed to study the structural characteristics and properties of perovskites at the atomic level. CsBi x Pb 1− x Br 3 perovskites doped with Bi at concentrations of 0.0059, 0.0072, and 0.0120 were studied. The importance of high-quality materials for applications in optics and photonics was noted. 133 Cs NMR showed high sensitivity for studying these concentrations of Bi, which affect the stability of perovskites and their dynamic parameters.

The main object of this work was to characterize the structure and properties of laboratory-made fish gelatin from cod skin in comparison with known commercial gelatins of fish and mammalian origin. This is one way we can contribute to the World Food Program and characterize foodstuff resources from alternative natural sources. Our research was based on the combination of an expanded set of complementary physical-chemical methods to study the similarities and distinctions of hydrogels from traditional and novel gelatin sources from underused marine resources. In this work, we have compared the morphology, supramolecular structure and colloid properties of two commercial (mammalian and fish) gelatins with gelatin we extracted from cold-water cod skin in laboratory conditions. The obtained results are novel, showing that our laboratory-produced fish gelatin is much closer to the mammalian one in terms of such parameters as thermal stability and strength of structural network under temperature alterations. Especially interesting are our experimental observations comparing both fish gelatins: it was shown that the laboratory-extracted cod gelatin is essentially more thermally stable compared to its commercial analogue, being even closer in its rheological properties to the mammalian one.

Two-dimensional black phosphorus (BP) has attracted great attention as a perspective material for various applications. The chemical functionalization of BP is an important pathway for the preparation of materials with improved stability and enhanced intrinsic electronic properties. Currently, most of the methods for BP functionalization with organic substrates require either the use of low-stable precursors of highly reactive intermediates or the use of difficult-to-manufacture and flammable BP intercalates. Herein we report a facile route for simultaneous electrochemical exfoliation and methylation of BP. Conducting the cathodic exfoliation of BP in the presence of iodomethane makes it possible to generate highly active methyl radicals, which readily react with the electrode’s surface yielding the functionalized material. The covalent functionalization of BP nanosheets with the P–C bond formation has been proven by various microscopic and spectroscopic methods. The functionalization degree estimated by solid-state 31P NMR spectroscopy analysis reached 9.7%.

The synthesis of biocompatible and bioresorbable composite materials, such as a “polymer matrix-mineral constituent,” stimulating the natural growth of living tissues and the restoration of damaged parts of the body, is one of the challenging problems in regenerative medicine and materials science. Composite films of bioresorbable polymer of polyvinylpyrrolidone (PVP) and hydroxyapatite (HA) were obtained. HA was synthesized in situ in the polymer solution. We applied electron paramagnetic resonance (EPR) and nuclear magnetic resonance (NMR) approaches to study the composite films’ properties. The application of EPR in two frequency ranges allowed us to derive spectroscopic parameters of the nitrogen-based light and radiation-induced paramagnetic centers in HA, PVP and PVP-HA with high accuracy. It was shown that PVP did not significantly affect the EPR spectral and relaxation parameters of the radiation-induced paramagnetic centers in HA, while light-induced centers were detected only in PVP. Magic angle spinning (MAS) 1H NMR showed the presence of two signals at 4.7 ppm and −2.15 ppm, attributed to “free” water and hydroxyl groups, while the single line was attributed to 31P. NMR relaxation measurements for 1H and 31P showed that the relaxation decays were multicomponent processes that can be described by three components of the transverse relaxation times. The obtained results demonstrated that the applied magnetic resonance methods can be used for the quality control of PVP-HA composites and, potentially, for the development of analytical tools to follow the processes of sample treatment, resorption, and degradation.

A library of 31 mono- and bis-quaternary ammonium compounds based on 3-hydroxypyridine was synthesized. Primary screening of their antibacterial activity in vitro in six archival strains of bacteria revealed four highly active lead compounds surpassing commercial antiseptics benzalkonium chloride, miramistin, and chlorhexidine in their activity. Further in-depth study of the antibacterial activity of the lead compounds in vitro in 16 clinical bacterial strains and the study of their toxicity in vitro and in vivo showed that 2,6-bis(N,N-dimethyl-N-dodecylammoniomethyl)-3-methoxypyridine dichloride was the most active and least toxic and manifested a higher activity in comparison with benzalkonium chloride, miramistin, and chlorhexidine in clinical isolate of both gram-positive and gram-negative bacteria, as well as a moderate toxicity in vivo (LD 50 = 82 6 mg kg −1 , mice, oral administration). The quaternary ammonium compounds based on 3-hydroxypyridine are of undoubted interest for the further development of antibacterial drugs.

We report herein the design, synthesis and biological evaluation of series of 7-substituted fluoroquinolones with pyridoxine derivatives. In vitro screening of antibacterial activity and toxicity of 39 synthesized fluoroquinolones defined compounds 7 and 28 as lead compounds for further investigations. On various clinical isolates lead compounds 7 and 28 exhibited antibacterial activity comparable with reference fluoroqinolones. Mutagenic effects haven't been observed for these compounds in SOS-chromotest. Compound 7 are non-toxic in vivo on mice (LD50 > 2000 mg/kg, oral) and rats (LD50 > 2000 mg/kg, oral). Compound 28 was more toxic (LD50 = 474 mg/kg, oral, mice). Moreover compound 7 showed greater in vivo efficacy compared to ciprofloxacin in a murine model of staphylococcal sepsis. Taken together the described active compound are promising candidate for preclinical trials.

Two-dimensional black phosphorus (BP) has emerged as a perspective material for various micro- and opto-electronic, energy, catalytic, and biomedical applications. Chemical functionalization of black phosphorus nanosheets (BPNS) is an important pathway for the preparation of materials with improved ambient stability and enhanced physical properties. Currently, the covalent functionalization of BPNS with highly reactive intermediates, such as carbon-free radicals or nitrenes, has been widely implemented to modify the material’s surface. However, it should be noted that this field requires more in-depth research and new developments. Herein, we report for the first time the covalent carbene functionalization of BPNS using dichlorocarbene as a functionalizing agent. The P–C bond formation in the obtained material (BP–CCl2) has been confirmed by Raman, solid-state 31P NMR, IR, and X-ray photoelectron spectroscopy methods. The BP–CCl2 nanosheets exhibit an enhanced electrocatalytic hydrogen evolution reaction (HER) performance with an overpotential of 442 mV at −1 mA cm−2 and a Tafel slope of 120 mV dec−1, outperforming the pristine BPNS.

We synthesized a number of new derivatives of phenolic glycoside saccharumoside-B based on pyridoxine and 3-hydroxy-2-methylpyridine and studied their cytotoxicity in vitro against three normal (HEK-293, Chang Liver, MSC) and nine tumor (MCF-7, MDA-MB-231, A-498, SNB-19, M-14, NCI-H322M, HCT-115, HCT-116, PC-3) human cell lines compared with camptothecin, doxorubicin, and saccharumoside-B. The effect of the peripheral fragments of phenolic glycoside on the target activity was studied and the structure-antitumor activity relationship was established. A new efficient approach to the synthesis of saccharumoside-B was proposed.

Diethylphosphinylmethanehydrazide, the first representative of the phosphorylated formic acid hydrazides with three P-C bonds was obtained, which can exhibit neurotropic activity. Its one-pot synthesis from diethylchlorophosphine, alkyl chloroformate, trimethyl orthoformate, and hydrazine hydrate was developed. The addition of the hydrazide to phosphorylated 4-methylenequinones afforded compounds which can have biological and antioxidant activity.

The paper demonstrated the increase of the surface area and meso- and microporosity volume with the low concentration Mg-substitution introduction during the hydroxyapatite (HA) wet method synthesis, as well as samples phase and structure evolution during the heat treatment up to 1200 degrees C. The incorporation of 0.1 and 1.0 mol.% Mg2+ were studied by magnetic resonance techniques including electron paramagnetic resonance (EPR), electron-nuclear double resonance (ENDOR), magic angle spinning nuclear magnetic resonance (MAS NMR) depending on Mg2+ content, and thermal treatment temperature. The calculation based on Density Functional Theory (DFT) was conducted and a model of the Mg2+ introduction was proposed, which correlated with the unit cell volume evaluations. Incorporation of 0.1 mol. % Mg2+ resulted in the growth of specific surface area (S) on the 37%, while 1.0 mol. % Mg-HA powders demonstrated a more than three times increase of surface area up to 86.91 m2/g compared to 23.35 m2/g for pure HA. The micro-and mesopores volume also demonstrated the near three time growing up with a total pore volume of 0.2938 mm3/g. The established properties indicated the opportunity to apply these materials for water, air, and soil purification, catalyst, as well as active phase support and bone tissue repair including drugs and proteins delivery systems. The in vitro investigations demonstrated the cytocompatibility of the bioceramic granules and confirmed the positive influence of the Mg2+ on cell viability and proliferation.

Application of high resolution 13C nuclear magnetic resonance (NMR) spectroscopy to characterize crude oil was demonstrated. The chemical shifts of 13C NMR functional groups that determine the composition of the oil sample were determined. Molar fractions of primary, secondary, quaternary, tertiary, aromatic groups, aromatic factor and average hydrocarbon chain length of aliphatic hydrocarbons of the oil sample according to 13C NMR spectra were determined. Detailed description of the 13C NMR spectra of the oil sample using a single consideration of three NMR spectra: 13C, 13C Attached Proton Test (APT), 13C with Gated Decoupling (GD) was performed. The different contribution of the studied oil sample in the aliphatic (10–75 ppm) and aromatic (115–165 ppm) areas of the 13C NMR spectra was determined. The presence of all major hydrocarbon components in the studied oil sample was established on the quantitative level, the aromaticity factor and the mean length of the hydrocarbon chain were evaluated. Quantitative fractions of aromatic molecules and functional groups constituting oil hydrocarbons were determined. In this work we demonstrate that the attached proton test and gated decoupling 13C NMR spectroscopy can afford all information to complete the chemical shift assignment of an oil sample, especially for determination of long range 1H–13C coupling constants and 13C multiplicity.

We studied the diffusion of ionic liquid ethylammonium nitrate confined within pores of two types of porous glass, Vycor and Varapor, with average pore sizes of 4 nm and 9.8 nm, respectively, by H-1 NMR in the temperature range of 295-325 K. The diffusional behavior of the ionic liquid corresponds to long-term diffusion in a system of interconnected pores. It was shown that the diffusivity of EAN confined in Varapor is controlled by the porous system's tortuosity and does need to take into consideration the interaction with the surface of the discrete pore walls. In the case of Vycor, the long-term diffusivity is a factor 1.5 lower than that expected in the absence of interaction with the pore walls. Two possible mechanisms that may explain this discrepancy are the EAN-surface interaction and retardation of EAN diffusion compared to n-decane in smaller pores present in Vycor porous glass due to pore size distribution. Confinement of EAN in nanoporous glass does not leads to the EAN phase transformation observed earlier for alkylammonium nitrates enclosed in a micrometer-sized layer. Prolonged exposure of EAN to a strong static magnetic field does not leads to changes in the NMR and diffusivity of EAN over time. (C) 2022 The Author(s). Published by Elsevier B.V.

Self-diffusion of ions in the protic ionic liquid ethylammonium nitrate (EAN) was studied by 1H NMR pulsed field gradient techniques between 294 and 393 K in the presence of a PTFE insert in a 5-mm NMR tube. At all temperatures, the bulk diffusion of ions (measured by 1H and 15N NMR) can be described by a unique diffusion coefficient. The presence of solid hydrophobic surfaces of PTFE induces regions of EAN in their vicinity, where diffusion of ions, both cations and anions, is reduced compared to the bulk values. An additional line-shape analysis in 1H NMR spectra showed that local mobility of ethylammonium cations in the surface layers near PTFE is also reduced.