New 5-[4(3)-R-phenyl]-2,2′-bipyridines bearing the 1,1,7,7-tetrakis(tert-butoxycarbonylmethyl)-1,4,7-triazaheptane (DTTA) moiety at the C(6) position (R = Cl, Br, CF3) and their water-soluble EuIII complexes were synthesized. The photophysical properties of the synthesized complexes were investigated. More efficient sensitization of Eu3+ cation luminescence was demonstrated for a number of halogen-containing ligands. Some chelates exhibited moderate cell-staining ability. The synthesized compounds did not show significant photodynamic activity, which may be due to the inhibition of the in situ generation of reactive oxygen species via the supposed interaction with the methylene moiety of DTTA-appended 2,2′-bipyridine ligands.

We report the synthesis and characterization of a new 4-methoxyphenyl-2,2’-bipyridine-based ligand, such as 12, bearing dipicolylaminomethyl core as a receptor unit, as a probe for the fluorescence “turn-on” detection of Zn2+. Thus, in the presence of Zn2+ the probe 12 exhibited a fluorescence enhancement with a Stokes shift of 180 nm and photoluminescence quantum yields value of 1.0. In addition, 12 exhibited higher binding constant for Zn2+ ( 2 × 105 M−1) with the LOD reaching the nanomolar level ( 0.1 × 10–9 M) compare to the previously reported probe 1. The stoichiometry and structure of the [Zn(12)]2+ and [Zn(1)]2+ complexes were supported by XRD analysis, DFT calculations and 1H NMR experiments. It was postulated that, as a result of binding of Zn2+, the sample exhibited a bright “on” state via the PET-ICT processes. Molecular docking studies and confocal fluorescence microscopy experiments demonstrated that the probe 12 could be used for the fluorescence detection of Zn2+ not only in artificially enriched with zinc salts live cells, but also in fixed tissues with cations are in a bound state. The high binding constant of compound 12 to Zn2+ cation allows it to be used for the accurate localization of pancreatic beta cells (islets of Langerhans).

New (bi)pyridine derivatives of the antimicrobial drug ornidazole were synthesized by alkylation of pyridyl- and 2,2′-bipyridyl-phenolic derivatives for the first time. The proposed methodology makes it possible to expand the range of ornidazole derivatives with increased antibacterial activity.

A convenient synthetic approach to 2-(2,2'-bipyridin-6-yl)-1,3,4-oxadiazole derivatives is proposed, which involves the preparation of 5-aryl-2,2'-bipyridine-6-carboxylic acid esters by the “1,2,4-triazine” methodology and the subsequent construction of the 1,3,4-oxadiazole ring via the modification of the ester group.

A convenient synthetic approach to derivatives of 2-(2,2ʹ-bipyridin-6-yl)-1,3,4-oxadiazoles is proposed as a result of the preparation using the “1,2,4-triazine” methodology of esters of 5-aryl-2,2ʹ-bipyridine-6-carboxylic acids and the subsequent construction of the 1,3,4-oxadiazole cycle by to modification of the ester group.

The release rate of active pharmaceutical ingredients (APIs) from tablet dosage forms is significantly influenced by the composition of the formulation, in particular filler composition. In this work, we analyzed the impact of the ratio of excipients on the release rate of vinpocetine from a tablet containing Ginkgo biloba L. extract as the second API. Microcrystalline cellulose (MCC), hydroxypropylcellulose (L-HPC) mixed with MCC (up to 16% of HPC), and partially pregelatinized starch were used in different ratios as excipients. Moreover, tween-80 was used to study the effect of introduction of emulsifier on the APIs’ release rates. According to our findings, optimal APIs’ release rates are achieved when using the combination of MCC with HPC at a ratio of 2:3.

A convenient method has been proposed for the preparation of new derivatives of adamantine-based drugs, such as memantine and rimantadine. The synthesis was performed by functionalization of amino-group of memantine and rimantadine by ipso- substitution of cyano-group at C 5 position of 1,2,4-triazine scaffold with the corresponding aminoadamantane moieties with subsequent aza -Diels–Alder transformation of 1,2,4-triazine cycle into pyridine one in some cases.

A series of new indolyl- and pyrrolyl-substituted 2,2′-bipyridines were reported as push–pull fluorophores/probes by using a sequence of the nucleophilic substitution reaction of hydrogen (S N H) and inverse-demand Diels–Alder reaction.

An efficient procedure has been developed for the synthesis of 2-phenyl-1,3,4-oxadiazole deriva­tives with one or two pyrrolidin-1-yl substituents in the benzene ring via nucleophilic substitution of fluorine in 2-[(di)fluorophenyl]-1,3,4-oxadiazole on heating with pyrrolidine under solvent-free conditions.

Linked to Alzheimer’s disease (AD), amyloids and tau-protein are known to contain a large number of cysteine (Cys) residues. In addition, certain levels of some common biogenic thiols (cysteine (Cys), homocysteine (Hcy), glutathione (GSH), etc.) in biological fluids are closely related to AD as well as other diseases. Therefore, probes with a selective interaction with the above-mentioned thiols can be used for the monitoring and visualizing changes of (bio)thiols in the biological fluids as well as in the brain of animal models of Alzheimer’s disease. In this study, new Eu(III), Tb(III), Gd(III) and Sm(III) complexes of 2,2′-bipyridine ligands containing TEMPO fragments as receptor units for (bio)thiols are reported. The presence of free radical fragments of the ligand in the complexes was proved by using the electronic paramagnetic resonance (EPR) method. Among all the complexes, the Eu(III) complex turned out to be the most promising one as luminescence- and spin-probe for the detection of biogenic thiols. The EPR and fluorescent titration methods showed the interaction of the resulting complex with free Cys and GSH in solution. To study the practical applicability of the probes for the monitoring of AD in-vivo, by using the above-mentioned Eu(III)-based probe, the staining of the brain of mice with amyloidosis and Vero cell cultures supplemented with the cysteine-enriched medium was studied as well as the fluorescence titration of Bovine Serum Albumin, BSA (as the model for the thiol moieties containing protein), was carried out. Based on the results of fluorescence titration, the formation of a non-covalent inclusion complex between the above-mentioned Eu(III) complex and BSA was suggested.

Two new water-soluble PAH-substituted (PAH - polyaromatic hydrocarbon) naphtho[1,2-d] [1,3]oxazole dyes 1-2 were synthesized and investigated for intramolecular charge transfer (ICT) behavior, aggregation, and ability to fluorescent staining and photosensitization on living cancer cells of HeLa and Vero cultures. To make clear this behavior a detailed analysis of the relationship between the structure and photophysical properties 1-2 were carried out based on experimental and computation data. As a result of the staining experiment, there was a diffuse distribution in the cytoplasm of 2-(9-anthracenyl)-containing naphthoxazole 1 as a hydrophilic fluorophore. Whereas 2-(1-pyrenyl)-derivative 2 showed accumulation in the endoplasmic reticulum, as well as additional distribution in lipid bilayers. Photodynamic activity of type II was confirmed for the cationic exogenous photosensitizer 2: the IC50 value in the case of HeLa cell culture was 0.50 mu M. The radical mechanism of photodynamic activity was determined by the EPR method.

The aim of this study was to asses hepatoxicity of riamilovir with repeated administration on the animal model. Materials and methods. Twenty non-linear guinea pigs were randomized into 4 groups: control and three experimental, receiving 64 days of daily riamilovir orally in doses of 48, 96, 144 mg/kg. Biochemical profile: ALT, AST, GGT, total protein, total and direct bilirubins, albumin, cholesterol, triglycerides: on 0, 33 and 65 days from the start of the experiment. Results. A significant decrease of serum albumin and cholesterol levels was found only in group 2 and there were no statistically significant changes of other indicators. Conclusion. The data obtained indicate afunctional liver synthetic function changes without signs of hepatobiliary and hepatocellular damage.

A POPOP analogue was synthesized using a progressive atom-economical click reaction with high yield. The resulting compound has similar photophysical properties compared to POPOP. The synthesized analogue has emission with a bathochromic shift.

The article presents the results of a quantitative determination of the number of flavonoids by spectrophotometry analysis in the leaves of Silybum marianum depending on the level of mineral nutrition. Also using the HPLC-UV method, 2 flavones-apigenin and luteolin-were identified. As a result, patterns of accumulation of flavonoids in Silybum marianum leaves from the regime of mineral nutrition were revealed. The maximum accumulation of flavonoids occurs when phosphorus and potassium fertilizers are introduced into the soil.

An effective approach to the synthesis of hybrid compounds, including fragments of 5-aryl-2,2'-bipyridines and pyrene, which are of potential interest from the point of view of practical application, has been developed.

As the moistures were used phenyl-, 4 '-aminophenil- and 4 '-pyrydil radicals. Photophysical properties of 1,3,4-oxadiazoles are considered. Such properties are recorded using three different solvent (acetonitrile, ethanol, and water). Then titration by trifluoroacetic acid is carried out. The bigger change in UV-visible spectrum was observed for 4-aminophenyl-5-(pyridin-4-yl)-1,3,4-oxadiazole.