The Determination of the Biocompatibility of New Compositional Materials, including Carbamide-Containing Heterocycles of Anti-Adhesion Agents for Abdominal Surgery.

Due to traumatic injuries, including those from surgical procedures, adhesions occur in over 50% of cases, necessitating exclusive surgical intervention for treatment. However, preventive measures can be implemented during abdominal organ surgeries. These measures involve creating a barrier around internal organs to forestall adhesion formation in the postoperative phase. Yet, the effectiveness of the artificial barrier relies on considerations of its biocompatibility and the avoidance of adverse effects on the body. This study explores the biocompatibility aspects, encompassing hemocompatibility, cytotoxicity, and antibacterial and antioxidant activities, as well as the adhesion of blood serum proteins and macrophages to the surface of new composite film materials. The materials, derived from the sodium salt of carboxymethylcellulose modified by glycoluril and allantoin, were investigated. The research reveals that film materials with a heterocyclic fragment exhibit biocompatibility comparable to commercially used samples in surgery. Notably, film samples developed with glycoluril outperform the effects of commercial samples in certain aspects.

Absorption of Water Vapor by Bambus[6]uril and a Density Functional Theory Study of Its Aqua Complexes.

The absorption/desorption of water vapor by bambus[6]uril (Bu[6]) has been studied. According to kinetic experiments, the absorption capacity of Bu[6] is 4 moles of water per 1 mole of Bu[6] with the absorption duration of 20 min and the complete desorption duration of 100 min. Experimental rate constants for water vapor absorption and desorption by Bu[6] have been determined to be 0.166 min-1 and 0.0221 min-1, respectively. The obtained results are in agreement with theoretical calculations using the DFT method. A hypothetical structure of bambus[6]uril tetrahydrate (Bu[6]·4H2O) has been proposed based on the experimental and DFT data.

Synthesis of Novel Phosphorus-Containing Derivatives of 1,3,4-Trimethylglycoluril via the Birum-Oleksyszyn Reaction.

This work presents the synthesis of a new compound, 1-[aryl-(diphenylphosphono)methyl]-3,4,6-trimethylglycolurils, via the interaction of benzaldehyde and its mononitro- and monohydroxyderivatives with 1,3,4-trimethylglycoluril and triphenylphosphite. By varying the reaction conditions and the catalysts, the obtained product yields ranged from satisfactory to good. The diastereomers formed during the reaction were separated by semipreparative HPLC on the C18 stationary phase. The isolated diastereomers were characterized by 1H, 13C, and 31P NMR, and the structures of the diastereomers were confirmed using a single-crystal X-ray crystal structure analysis and quantum chemical calculations.

Methods of Analysis and Identification of Betulin and Its Derivatives.

This scientific work presents practical and theoretical material on the methods of analysis and identification of betulin and its key derivatives. The properties of betulin and its derivatives, which are determined by the structural features of this class of compounds and their tendency to form dimers, polymorphism and isomerization, are considered. This article outlines ways to improve not only the bioavailability but also the solubility of triterpenoids, as well as any hydrophobic drug substances, through chemical transformations by introducing various functional groups, such as carboxyl, hydroxyl, amino, phosphate/phosphonate and carbonyl. The authors of this article summarized the physicochemical characteristics of betulin and its compounds, systematized the literature data on IR and NMR spectroscopy and gave the melting temperatures of key acids and aldehydes based on betulin.

Rotational Barriers in N-Benzhydrylformamides: An NMR and DFT Study.

N-Benzhydrylformamides are pharmacologically active compounds with anticonvulsant, enzyme-inducing, antihypoxic, and other types of biological activity. The conformational behavior of benzhydrylformamides is determined to a great extent by the presence of substituents at the nitrogen atom and in the ortho-position(s) of the diphenylmethane moiety. Particularly, the NMR spectra of these compounds often contain two sets of signals originating from different orientations of the formyl group. With the use of the dynamic NMR method and DFT calculations, we investigated the internal rotations of aromatic and formyl fragments and estimated the corresponding rotational barriers in N-benzhydrylformamide (BHFA), N-methyl-N-benzhydrylformamide (BHFA-NMe), and in a series of ortho-halogen-substituted N-benzhydrylformamides. It was found that the DFT method at M06-2X/6-311+G* level of theory satisfactorily reproduces the experimental barrier ΔG298≠(Formyl) of the formyl group rotation in BHFA-NMe. In BHFA, BHFA-NMe, and in the ortho-halogen derivatives, the calculated ΔG298≠(Formyl) values are close to each other and lie within 20-23 kcal/mol. On the other hand, the ortho-substituents significantly hinder the rotation of aryl fragment with ΔG298≠(Aryl) values varying from 2.5 kcal/mol in BHFA to 9.8 kcal/mol in ortho-iodo-N-benzhydrylformamide.

Development and validation of HPLC-UV method for quantitation of a new antithrombotic drug in rat plasma and its application to pharmacokinetic studies.

A selective and sensitive procedure for quantitation of a new antithrombotic drug (GRS) in rat plasma was developed and validated using an HPLC-UV. The method was validated according to recommendations of the FDA, EMA in terms of selectivity, linearity, accuracy, precision, recovery, matrix effect, stability, and carry-over. The preparation of the biological sample included liquid-liquid extraction with acetonitrile, separation of water-organic mixture with inorganic salts, organic phase clean-up with a sorbent (QuEChERS method), its evaporation to dryness and reconstitution of the residue with A:B eluents mixture (1:1). The chromatographic separations were performed on a micro-column 75 × 2 mm, 5 µm particle size sorbent ProntoSIL 120-5-C18 AQ. The flowrate was of 0.15 ml/min, detector wavelength was set at 360 nm for GRS and at 230 nm for papaverine (IS). It was found that GRS recovery from rat plasma is 94%, the response linearity is in the range of 10 to 1000 ng ml-1. The accuracy values for intra-day determination were of 93.2 to 101.8%, for inter-day determination were of 91.2 to 102.2%, coefficient of variation for intra- and inter-day precision did not exceed 4.1 to 9.3%. The application of the method was shown in pharmacokinetic studies of GRS in rats at a dose of 20 mg kg-1.