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In the food industry, the pulsed electric field (PEF) technique is used to support the process of extraction of various substances. The aim of this study was to analyze the effect of a number of PEF pulses applied to peppermint and caraway on both the content of essential oils (EO) and their spectroscopic properties. The examined herb species were placed in a special vessel in the working chamber of the device between two electrodes providing high voltage electric pulses. The pulses were delivered 0, 150, 250, and 350 times per a studied sample of each herb. Essential oils were then obtained by way of hydrodistillation. The infrared spectra for all samples were measured using an FTIR spectrometer in the spectral range of 3700–730 cm−1. The applied electric field of a predetermined number of pulses had no significant effect on the amount of distilled essential oil from caraway fruit, while in the case of peppermint, it caused a slight decrease in relation to the raw material not subjected to PEF exposure. It was found that the analysis of infrared spectra made it possible to compare the quality of the obtained oils with each other and to pre-determine their compositions.

HighlightsOxygen-coordinated single-atom Mn catalyst was fabricated via introducing oxygen functional groups rich bacterial cellulose as the adsorption regulator through a combined impregnation–pyrolysis–etching synthetic route.Mn–O–C as the electrocatalyst exhibits superior electrocatalytic activity toward ammonia synthesis with a maximum NH3 yield rate of 1476.9 ± 62.6 μg h−1 cm−2 at − 0.7 V (vs. RHE) and a faradaic efficiency of 89.0 ± 3.8% at − 0.5 V (vs. RHE) under ambient conditions.Electrocatalytic mechanism of Mn–(O–C2)4 site for nitrate reduction reaction is unveiled by a combination of in situ spectroscopy characterization and computational study.Electrocatalytic nitrate reduction reaction has attracted increasing attention due to its goal of low carbon emission and environmental protection. Here, we report an efficient NitRR catalyst composed of single Mn sites with atomically dispersed oxygen (O) coordination on bacterial cellulose-converted graphitic carbon (Mn–O–C). Evidence of the atomically dispersed Mn–(O–C2)4 moieties embedding in the exposed basal plane of carbon surface is confirmed by X-ray absorption spectroscopy. As a result, the as-synthesized Mn–O–C catalyst exhibits superior NitRR activity with an NH3 yield rate (RNH3) of 1476.9 ± 62.6 μg h−1 cm−2 at − 0.7 V (vs. reversible hydrogen electrode, RHE) and a faradaic efficiency (FE) of 89.0 ± 3.8% at − 0.5 V (vs. RHE) under ambient conditions. Further, when evaluated with a practical flow cell, Mn–O–C shows a high RNH3 of 3706.7 ± 552.0 μg h−1 cm−2 at a current density of 100 mA cm−2, 2.5 times of that in the H cell. The in situ FT-IR and Raman spectroscopic studies combined with theoretical calculations indicate that the Mn–(O–C2)4 sites not only effectively inhibit the competitive hydrogen evolution reaction, but also greatly promote the adsorption and activation of nitrate (NO3−), thus boosting both the FE and selectivity of NH3 over Mn–(O–C2)4 sites.

Binary complexes of α-hydroxy acids (L-Tartaric acid and L-Malic acid) with d-electron metal ions (copper, cobalt, nickel) were investigated. Potentiometric measurements have been performed in aqueous solution with computer analysis of the data for determination of the stability constants of complexes formed in the studied systems. The coordination mode of the complexes was defined using spectroscopic methods: electron paramagnetic resonance (EPR), ultraviolet-visible (UV-Vis), circular dichroism (CD), and infrared (IR). Results of the equilibrium studies have provided evidence for the formation of dimers with copper(II) ions and monomers with cobalt(II) and nickel(II) ions.

Flavonoids are biologically active natural products of great interest for their potential applications in functional foods and pharmaceuticals. A hesperetin-7-O-glucoside inclusion complex with β-cyclodextrin (HEPT7G/βCD; SunActive® HCD) was formulated via the controlled enzymatic hydrolysis of hesperidin with naringinase enzyme. The conversion rate was nearly 98%, estimated using high-performance liquid chromatography analysis. The objective of this study was to investigate the stability, solubility, and spectroscopic features of the HEPT7G/βCD inclusion complex using Fourier-transform infrared (FTIR), Raman, ultraviolet–visible absorption (UV–vis), 1H- and 13C- nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC), liquid chromatography/mass spectroscopy (LC–MS), scanning electron microscopy (SEM), and powdered X-ray diffraction (PXRD) spectroscopic techniques including zeta potential, Job’s plot, and phase solubility measurements. The effects of complexation on the profiles of supramolecular interactions in analytic features, especially the chemical shifts of β-CD protons in the presence of the HEPT7G moiety, were evaluated. The stoichiometric ratio, stability, and solubility constants (binding affinity) describe the extent of complexation of a soluble complex in 1:1 stoichiometry that exhibits a greater affinity and fits better into the β-CD inner cavity. The NMR spectroscopy results identified two different configurations of the HEPT7G moiety and revealed that the HEPT7G/βCD inclusion complex has both –2S and –2R stereoisomers of hesperetin-7-O-glucoside possibly in the –2S/–2R epimeric ratio of 1/1.43 (i.e., –2S: 41.1% and –2R: 58.9%). The study indicated that encapsulation of the HEPT7G moiety in β-CD is complete inclusion, wherein both ends of HEPT7G are included in the β-CD inner hydrophobic cavity. The results showed that the water solubility and thermal stability of HEPT7G were apparently increased in the inclusion complex with β-CD. This could potentially lead to increased bioavailability of HEPT7G and enhanced health benefits of this flavonoid.

The mode of coordination of copper(II) ions with dopamine (DA, L) in the binary, as well as ternary systems with Ado, AMP, ADP, and ATP (L′) as second ligands, was studied with the use of experimental—potentiometric and spectroscopic (VIS, EPR, NMR, IR)—methods and computational—molecular modeling and DFT—studies. In the Cu(II)/DA system, depending on the pH value, the active centers of the ligand involved in the coordination with copper(II) ions changed from nitrogen and oxygen atoms (CuH(DA)3+, Cu(DA)2+), via nitrogen atoms (CuH2(DA)24+), to oxygen atoms at strongly alkaline pH (Cu(DA)22+). The introduction of L′ into this system changed the mode of interaction of dopamine from oxygen atoms to the nitrogen atom in the hydroxocomplexes formed at high pH values. In the ternary systems, the ML′-L (non-covalent interaction) and ML′HxL, ML′L, and ML′L(OH)x species were found. In the Cu(II)/DA/AMP or ATP systems, mixed forms were formed up to a pH of around 9.0; above this pH, only Cu(II)/DA complexes occurred. In contrast to systems with AMP and ATP, ternary species with Ado and ADP occurred in the whole pH range at a high concentration, and moreover, binary complexes of Cu(II) ions with dopamine did not form in the detectable concentration.

A binary system of uridine-5′-diphosphoglucuronic acid with copper (II) ions was studied. Potentiometric studies in aqueous solutions using computer data analysis were carried out. The pH of dominance, the overall stability constants (logβ), and the equilibrium constants of the formation reaction (logKe) were determined for each complex compound formed in the studied system. Spectroscopic studies were carried out to determine the mode of coordination in the compounds studied. Cytotoxicity and metabolic activity tests of the compounds obtained showed an increase in the biological activity of the complexes tested against the free ligand. The current research may contribute to the knowledge of complex compounds of biomolecules found in the human body and may also contribute to the characterization of a group of complex compounds with potential anticancer properties.

Half-sandwich Ru(II) complexes belong to group of biologically active metallo-compounds with promising antimicrobial and anticancer activity. Herein, we report the synthesis and characterization of arene ruthenium complexes containing benzimidazole moiety, namely, [(η6-p-cymene)RuCl(bimCOO)] (1) and [(η6-p-cymene)RuCl2(bim)] (2) (where bimCOO = benzimidazole-2-carboxylate and bim = 1-H-benzimidazole). The compounds were characterized by 1H NMR, 13C NMR, IR, UV–vis and CV. Molecular structures of the complexes were determined by SC-XRD analysis, and the results indicated the presence of a pseudo-tetrahedral (piano stool) geometry. Interactions in the crystals of the Ru complexes using the Hirshfeld surface analysis were also examined. In addition, the biological studies of the complexes, such as antimicrobial assays (against planktonic and adherent microbes), cytotoxicity and lipophilicity, were performed. Antibacterial activity of the complexes was evaluated against S. aureus, E. coli, P. aeruginosa PAO1 and LES B58. Cytotoxic activity was tested against primary human fibroblasts and adenocarcinoma human alveolar basal epithelial cells. Obtained biological results show that the ruthenium compounds have bacteriostatic activity toward Pseudomonas aeruginosa PAO1 strain and are not toxic to normal cells. A molecular docking study was applied as a predictive source of information about the plausibility of examined structures binding with HSA as a transporting system.

This study presents comprehensive theoretical, spectroscopic, and biological investigations of the compound 5-Chloro-6-fluoro-2-(2-pyrazinyl)-1H-benzimidazole (5CF2PB). Density Functional Theory (DFT) calculations were performed at the B3LYP/6–311 +  + G(d,p) level, and a Potential Energy Scan (PES) was carried out to identify the most stable conformer and its optimized geometry. Theoretical vibrational frequencies and Potential Energy Distribution (PED) analysis were correlated with experimental FT-IR and FT-Raman spectra, showing excellent agreement. Experimental UV–Vis and 1 H– 13 C NMR spectra were recorded and compared with theoretical predictions using the IEF-PCM solvation model in DMSO, chloroform, and water. Frontier Molecular Orbital (FMO) analysis revealed a HOMO–LUMO energy gap of 4.043 eV, consistent with moderate chemical reactivity and optical absorption. The compound’s chemical reactivity descriptors, Molecular Electrostatic Potential (MEP), and topological parameters were analyzed through QTAIM, ELF, LOL, IRI, and RDG methods, providing insights into electronic structure and non-covalent interaction regions. Hirshfeld surface and 2D fingerprint analyses confirmed the dominance of halogen–hydrogen and halogen–nitrogen interactions in crystal packing. In-vitro antimicrobial screening demonstrated that 5CF2PB exhibits potent antibacterial and antifungal activities, particularly against Pseudomonas aeruginosa and Aspergillusniger , showing better efficacy than the standard drug ciprofloxacin. The PASS prediction suggested significant anti-mycobacterial potential, which was validated by molecular docking studies against the protein targets 6TE7 and 5O4L, yielding strong binding affinities and inhibition constants. Molecular dynamics simulations further confirmed the stability of the ligand–protein complexes. Overall, the integrated computational, spectroscopic, and biological analyses establish 5CF2PB as a promising multifunctional compound with potential pharmacological applications.

Vanillic acid is a phenolic compound recognized for its use as a flavoring agent in the food industry. It can be found in a variety of products, such as thyme, rice, oranges, cherries, green tea, wine, and beer. Vanillic acid has been substantiated to show various beneficial pharmacological properties including anti-inflammatory, antibacterial, cardioprotective, hepatoprotective, antitumorigenic, free radical scavenging, antioxidant and even antivenomous activity. Since vanillic acid has low bioavailability, and bioavailability of a compound depends (among other factors) on its chemical structure, testing isomers of vanillic acid may yield promising results. Several structural and biological studies were carried out to determine the correlation between the molecular structure and biological activity of vanillic acid and its isomers (isovanillic acid and o -vanillic acid). Studies have shown that changes in the electronic structure of vanillic acids affect their different reactivity, antioxidant activity, and cytotoxicity. O -vanillic acid, characterized by the highest reactivity, is a weak antioxidant and the best cytotoxic compound. No direct correlation was observed between the antioxidant activity of vanillic acids and their toxic effect on model cell lines, probably due to the different mechanisms of action in the phenomena studied.