The interaction between proteins and salts in aqueous solutions represents a compelling scientific problem in both biophysical and medical research. One manifestation of the interaction in the bovine serum albumin (BSA)-NaCl-H2O system is the formation of ordered patterns upon droplet drying. In our experiments, the topographic features of the deposited particles as well as their elemental composition were studied using optical microscopy and scanning electron microscopy (SEM). In this work, we experimentally investigated the stepwise change in the characteristic structures of the precipitate with an increase in the BSA concentration from 0.005 to 35 mg/mL. The formation of discrete BSA-NaCl ring deposits near the droplet edge and around crystallization centers in the interior at BSA concentrations of 0.05-1 mg/mL proved particularly interesting. We demonstrated the sequence of ring structure formation: the process primarily begins with the formation of BSA aggregates arranged in sectors around the circumference, which in turn serve as nucleation sites for NaCl crystallization. We propose a qualitative conceptual-phenomenological interpretation of the observed experimental effects. Concentration-dependent patterns in the emergence and development of other patterns (such as spikes, fractal structures, and chrysanthemum-like formations) were established. These results expand our understanding of protein behavior in aqueous-salt solutions. This can be used in medical diagnostics as biomarkers. The characteristic patterns presented in the work can serve as a useful experimental basis for further studies of the impact of physicochemical factors on proteins and other biopolymers.

The two-year research involving laboratory and field studies supported by Geant4 computer simulation is aimed at determining the optimal parameters of 1 MeV accelerated electrons and 80 keV X-ray pre-planting irradiation of wheat seeds in order to find the optimal dose range which increases the crop yield while making wheat plants more resistant to fungal diseases caused by species of the genus Septoria. During the laboratory studies we measured the germination rate and biometric properties of plants, as well as the type, number, and average diameter of fungi found in the irradiated and non-irradiated seeds after irradiation with electrons and X-rays with the dose range 2-1000 Gy. Following the laboratory studies showing that the doses exceeding 30 Gy decreased the germination rate of wheat, field studies evaluated the impact of pre-planting irradiation with the doses in the range of 5-30 Gy on the wheat productivity and the rate of fungal diseases in wheat plants grown from irradiated and non-irradiated seeds. It has been found that the dose range 5-15 Gy is more preferable for pre-planting wheat irradiation, both for e-beam and X-rays, since it increases the crop yield while making wheat plants more resistant to fungal diseases caused by species of the genus Septoria. The X-ray dose of 15 Gy is found to be the most effective since it increased the yield up to 40% and also suppressed the Septoria glume blotch up to 40%. Since seed irradiation requires a particularly delicate approach given that the goal of irradiation is not only to reduce the rate of fungal diseases in the plants but also to increase the crop yield without detriment to the soil and the plant itself, consistency of dose uniformity across the seeds during pre-planting irradiation ensures the high reliability and repeatability of the irradiation effect. Our approach to irradiation planning with the use of Geant4 computer simulation allows us to precisely estimate the dose distribution in individual seeds and the distribution of radiation-chemical yield of radicals occurring as result of radiolysis in order to predict the effect of pre-planting irradiation and select the optimal irradiation parameters for maximizing the yield and crop quality.

Untargeted urinary metabolomics presents significant challenges in analytical reproducibility and biological interpretation, particularly in the context of clinical oncology. This study presents a systematically optimized liquid chromatography-high-resolution mass spectrometry (LC-HRMS) workflow for bladder cancer (BCa) biomarker discovery. To address variability in sample preparation, a two-stage design of experiments (DoE) approach was applied to systematically optimize key parameters affecting metabolite extraction efficiency, thereby improving the reproducibility of subsequent non-invasive profiling. The performance of the workflow was evaluated through the systematic assessment of instrumental stability and injection precision using pooled quality control (QC) samples. Following peak picking and alignment, a comprehensive raw dataset of 15,344 metabolic signals was generated, leading to the putative identification of 854 compounds. Unsupervised principal component analysis (PCA) demonstrated reproducible instrumental performance, indicated by tight QC sample clustering. From the total clinical cohort of 107 patients, a demographically matched sub-cohort of 50 individuals was evaluated to suppress confounding physiological noise. This comparative model revealed distinct disease-specific clustering and demonstrated significant perturbations in the tryptophan metabolic axis, membrane lipid remodeling, and enhanced proteolytic activity, characterized by an evident peptide overflow, associated with BCa progression. This systematically optimized methodology provides a reliable analytical approach for identifying non-invasive diagnostic panels, supporting the implementation of efficient laboratory workflows aligned with Analytics 5.0 principles.

Photodynamic therapy (PDT) is a clinically approved therapeutic modality with great potential for the treatment of cancers due to its excellent spatiotemporal selectivity and noninvasivenes. A combination of light-controlled chemotherapy (PACT) and PDT in one molecule has the potential to overcome crucial drawbacks of both Pt-based chemotherapy and PDT via a synergetic effect. Herein, we report a Pt(IV)-BODIPY agent for dual light-controlled chemophotodynamic therapy, a Pt(IV) prodrug with a BODIPY orthogonal dimer in the axial position. The orthogonal arrangement of the fluorophores results in a long-lived, "heavy-atom-free" triplet state of the dimeric fluorophore. The high quantum yield of singlet oxygen for the dimer fluorophore and the Pt(IV) prodrug based on it was confirmed, and the formation of the triplet state was demonstrated by flash photolysis. The excellent photosensitive properties of the Pt(IV) prodrug on SK-BR-3 and MCF-7 tumor cells demonstrate photocontrolled toxicity and potential for the development of dual therapy conjugates.

Electron beam irradiation, extensively used for suppressing a wide range of pathogens contaminating food products, pharmaceuticals and biological raw materials, inevitably damages the surrounding proteins, stripping the product of its essential nutritional and functional properties. This issue can be addressed by adjusting the electron beam irradiation dose, bearing in mind the concentration of proteins in the product since it can affect the rate of radiation-induced modifications in proteins. The study investigates the impact of 7.5 MeV electron-beam irradiation on modifications in bovine serum albumin (BSA) molecules in 0.9% NaCl solution in the concentration range of 0.5-70 mg/mL, encompassing a wide range of protein concentrations in food products, pharmaceuticals and biological raw materials. Conformational changes and aggregation of BSA were evaluated using UV-Vis spectrophotometry at λ = 350 nm. Peptide bond rupture in protein native structures was assessed by performing HPLC-MS/MS analysis after trypsin hydrolysis using three selected peptides located in different domains of the BSA amino acid sequence. It was found that the rate of radiation-induced modifications increased with an increase in the irradiation dose but decreased markedly as BSA concentration increased. While at the BSA concentration of 0.5 mg/mL over 87% of BSA molecules underwent peptide bond rupture under irradiation with a dose of 5 kGy, a two-fold increase in the BSA concentration and irradiation dose enabled bond rupture in only 20% of BSA molecules. Our experimental approach resulting in the development of the dose and concentration model allows us to quantify the degree of radiation-induced protein modifications depending on the irradiation dose and protein concentration in food products, pharmaceuticals and biological raw materials.

When quantifying gluten, it is important to ensure that variations of the protein composition in samples due to environmental influences or genetic differences between cultivars do not affect the analytical results. One way to achieve this is to use multiple quantitative markers that cover the majority of gluten proteins in the sample. This study advances our previously developed liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for gluten quantification by introducing an automated workflow for marker peptide selection and data processing. The algorithm identifies optimal combinations of peptides, reducing the time and labor costs associated with manual selection. The evaluation confirmed that algorithm-derived marker sets perform equivalently to those selected by the operator, which was demonstrated by reproducing analytical procedures for gluten determination developed earlier. The method previously used to assess the content of gluten originating from wheat was tested for another gluten source: rye. It showed acceptable precision and recovery, with an overall lower limit of quantification of 10 mg gluten/kg product, demonstrating the applicability of the method to matrices other than wheat. Automated data processing further improves robustness and facilitates routine implementation.

During the development of food radiation processing protocols, one of the aims is to find an optimal dose range for a specific type of product in which pathogenic microflora are inhibited while biochemical and organoleptic properties are not disturbed. When various food products are exposed to ionizing radiation, volatile organic compounds (VOCs) are formed. Depending on the radiation dose, the list of VOCs and their content change, so they could be considered marker compounds for the description of irradiation-related processes. This work proposes a universal way to study and compare the profile of volatile compounds in products of animal and plant origin using GC-MS in combination with various data representation techniques, including unsupervised machine learning methods. The VOC profiles of beef, chicken, turkey, fish, and potatoes were examined.

This study investigates the impact of 1 MeV electron beam and 80 keV X-ray irradiation on the decomposition rate and radiation–chemical yield of 1-hexanol in aqueous saline solution to develop a comprehensive approach to determining reliable volatile organic compound markers for food irradiation. A 50 mg/L 1-hexanol solution was irradiated with the doses ranging from 100 to 8000 Gy at various dose rates ranging from 0.2 to 10 Gy/s to assess the impact of irradiation parameters on the decomposition rate and radiation–chemical yield of volatile compounds typically found in food. GC–MS analysis revealed a non-linear decrease in 1-hexanol concentration with increasing dose, accompanied by the formation of aldehydes, ketones, and secondary alcohols. Among these products, hexanal was detected at the lowest applied dose and exhibited dose-dependent behavior that correlated strongly with 1-hexanol degradation. Density functional theory calculations identified the most probable pathways for the formation of hexanol decomposition products, involving direct ionization, radical reactions, and oxidation. A mathematical model proposed in the study describes dose-dependent transformations of 1-hexanol into hexanal, enabling quantitative estimation of the degradation extent of hexanol. The findings suggest that hexanal can serve as a quantitative marker for hexanol degradation, supporting the development of rapid “dose range” determination methods for food irradiation that ensure microbial safety while minimizing undesirable oxidation of proteins, fats, and carbohydrates.

Metronidazole (MNZ) is one of the most commonly used antibiotics in the food industry. High levels in food can lead to the development of antimicrobial resistance in humans, so it is important to monitor its levels in food. In the context of legal proceedings, it is frequently necessary to re-examine samples after an extended period of time. It is therefore crucial to ensure that the analytes in question do not degrade during the storage period. In this study, HPLC-MS/MS approach was validated and used to analyze levels of MNZ and its hydroxy metabolite in chicken eggs during storage in the refrigerator (+4 degrees C) and in the freezer (-20 degrees C) for 3 months. An analyte solution was administered to hens to obtain eggs containing MNZ and hydroxymetronidazole (MNZ-OH). The dependence of the analyte content in eggs as a function of time after sampling was also investigated.

Oxidation of lipids and proteins occurs in food products with a high concentration of fat and water such as chilled meat and fish under the action of ionizing radiation, which leads to the formation of volatile organic compounds (VOCs) in the product and appearance of specific smell and taste. During storage, various biochemical processes occur in processed chilled products which also result in a change in the concentration of VOCs that affect the organoleptic properties of the product. The accumulation of volatile compounds identified in beef samples both immediately after radiation processing and within four days after irradiation is studied by gas chromatography–mass spectrometry to determine the effective dose range for the radiation processing of beef. Monitoring of the concentration of VOCs in samples of chilled beef meat irradiated with accelerated electrons with the energy of 1 MeV in a dose range of 0.25 to 5 kGy reveals explicit dependences of the concentrations of certain alcohols, aldehydes, and alkanes on the absorbed dose and storage time. The proposed mathematical model that describes the dependences of the concentrations of VOCs identified immediately after irradiation in beef samples on the irradiation dose is based on the simultaneous occurrence of two competing processes: decomposition of compounds due to their oxidation and accumulation due to the oxidation of other compounds after exposure to ionizing radiation. It is found on the basis of the results of the study that the effective dose range of radiation processing is 250 to 1000 Gy.

Catalase serves as a crucial component of the antioxidant defense system by catalyzing the decomposition of hydrogen peroxide into water and molecular oxygen. This study investigated the effects of 1 MeV accelerated electron irradiation on catalase activity in model solutions at doses of 100 Gy and 1000 Gy. Enzyme activity was assessed using two complementary methods: spectrophotometric analysis and the oxygen bubble method. The experimental results demonstrated dose-dependent inhibition of catalase activity, indicating that substantial radiation-induced structural modifications may occur in the enzyme molecule as a result of irradiation. To understand the relationship between the irradiation dose and the catalase inhibition, calibration curves plotting the dependencies of hydrogen peroxide decomposition rate and the delayed appearance of oxygen bubbles after adding hydrogen peroxide to catalase saline solution on the catalase concentration showed a 1.5-fold reduction in catalase activity at 100 Gy and a 40-fold decrease at 1000 Gy. Based on these findings, we propose a novel biodosimetry approach utilizing the oxygen bubble formation delay time as an express assessment tool for detecting high radiation doses absorbed by biological objects, for example, food products. The results obtained in the study have important implications for evaluating radiation effects on biological systems, in particular catalase-containing food products, offering potential applications in radiation safety monitoring and food quality control.

Light induced release of cisplatin from Pt(IV) prodrugs is a promising tool for precise spatiotemporal control over the antiproliferative activity of Pt-based chemotherapeutic drugs. A combination of light-controlled chemotherapy (PACT) and photodynamic therapy (PDT) in one molecule has the potential to overcome crucial drawbacks of both Pt-based chemotherapy and PDT via synergetic effect. Herein we report green-light activated Pt(IV) prodrugs GreenPt with BODIPY-based photosentitizer in axial position with incredible high light response and singlet oxygen generation ability. GreenPt demonstrated the ability to release cisplatin under low-dose green light irradiation up to 1 J/cm2. The investigation of the photoreduction mechanism of GreenPt prodrug using DFT modeling and ΔG0 PET estimation revealed that the anion-radical formation and substituent photoinduced electron transfer from the triplet excited state of the BODIPY axial ligand to the Pt(IV) center is the key step in the light-induced release of cisplatin. Green-light activated BODIPY-based photosentitizers 5 and 8 demonstrated outstanding photosensitizing properties with extraordinary phototoxicity index (PI) >1300. GreenPt prodrug demonstrated gradual intracellular accumulation and light-induced phototoxicity with PI > 100, thus demonstrating dual action through light-controlled release of both cisplatin and a potent BODIPY-based photosensitizer.

Background: Recently, extensive use of antibiotics has increased the amount of antibiotic residues in the natural water environment. Methods: This study presents an experimental investigation into the degradation of penicillins, tetracyclines, streptomycin and chloramphenicol in aqueous solutions when exposed to 1 MeV accelerated electrons with doses of 0.1, 1, 3 and 7 kGy using HPLC-HRMS analysis. Results: It was found that electron beam irradiation with a dose of 7 kGy ensures 98-99% removal of antibiotics, with the initial concentrations ranging from 15 mg/L to 30 mg/L depending on the class of antibiotic. The mathematical model proposed in the study, which estimates the dose dependencies of the relative concentrations of antibiotics and their degradation products in aqueous solutions, reveals different decomposition rates of antibiotics of different classes due to the different radiosensitivities of antibiotics. It has been found that tetracycline has a considerably higher radiation-chemical yield compared to the other antibiotics when exposed to accelerated electrons. Conclusions: Using density functional theory in combination with the mathematical model, we have developed a novel approach to establishing a quantitative irradiation marker of antibiotic degradation as a result of irradiation, which involves finding the degradation product whose formation requires a minimum number of ionization events. Using such an approach, it is possible to establish the extent of antibiotic degradation in water after irradiation with different doses and find the optimal irradiation doses for industrial water treatment.

OBJECTIVES:Vitamin K homologues are essential to human health, and their concentrations in biological samples serve as valuable diagnostic biomarkers. This study was aimed to develop a method for determining vitamins K1 (phylloquinone, VK1) and K2 (menaquinone, MK-4) in human serum. The proposed method was validated and applied to the serum of a cohort of 20 Russian individuals. METHODS:High-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) was used to analyse the content of VK1 and MK-4 in serum. Atmospheric pressure chemical ionisation (APCI) in negative mode was applied to ionise VK1 and MK-4. Protein precipitation and solid-phase extraction (SPE) on polystyrene-divinylbenzene resin were combined to isolate and preconcentrate the analytes from serum. RESULTS:The HPLC-MSMS method was developed and validated for the determination of vitamins VK1 and MK-4 in human serum. The method demonstrated a lower limit of quantification (LLOQ) of 0.05 μg/L, with more than 71 % recoveries and precision within 17 %. To demonstrate the applicability of the method to real samples, serum from 20 healthy adults was analyzed. VK1 was detected in four individuals (0.094-0.96 μg/L), whereas MK-4 concentrations were below 0.22 μg/L in all cases. CONCLUSIONS:The validated HPLC-MS/MS workflow provides a reliable and sensitive approach for the quantification of VK1 and MK-4 in minimal serum volumes. The method demonstrates robustness, reproducibility, and suitability for large-scale analytical applications. The proposed LC-MS/MS protocol successfully applied to native human serum samples, illustrating its applicability for future clinical and biochemical studies involving vitamin K.

Substitution reactions in carbocyanine dyes are used to determine nucleophilic compounds. The interaction of a chlorine-containing carbocyanine dye with a number of medicinal substances is studied. It is shown that, in the reaction with isoniazid in the presence of a surfactant, this dye selectively changes color from yellow-green to violet. The formation of a product of the substitution of chlorine for isoniazid is proven by chromatography–mass spectrometry. The reaction proceeds in 20 min in the presence of 1 mM cetyltrimethylammonium bromide. The limit of detection for isoniazid in water by the photometric method is 10 μg/mL and in diluted artificial urine using fluorimetry, 0.3 μg/mL. The procedure does not use full-spectrum equipment, which simplifies the determination.

The objective of this study is to develop a universally applicable approach for establishing the optimal dose range for the irradiation of plant and animal products. The approach involves the use of the optimization function for establishing the optimal irradiation dose range for each category of plant and animal product to maximize the suppression of targeted pathogens while preserving the surrounding molecules and biological structures. The proposed function implies that pathogens found in the product can be efficiently suppressed provided that irradiation is performed with the following criteria in mind: a high irradiation dose uniformity, a high probability of irradiation hitting pathogens and controlled heterogeneity of radiobiological sensitivity of pathogens. This study compares the optimal dose ranges for animal and plant products using beef tenderloin and seed potato tubers as examples. In a series of experiments, our team traced the dose dependencies of myoglobin oxidation in beef and the amount of potential damage to albumin’s native structure. The behavior patterns of myoglobin derivatives and the amount of potential damage to albumin found in this study determined the optimal dose range, which appeared to be wider for beef irradiation compared to that for seed potato tubers, as they do not require uniform irradiation of the entire volume since targeted phytopathogens are predominantly found within the surface layers of the tubers. The use of proprietary methods involving spectrophotometry and high-performance liquid chromatography–mass spectrometry provides a novel perspective on the quantitative assessment of the myoglobin oxidation level and the potential damage to albumin’s native structure.

IntroductionPanax vietnamensis is a valuable medicinal plant and a source of a broad spectrum of biologically active ginsenosides of different structural groups. Overexploitation and low adaptability to planation cultivation have made this species vulnerable to human pressure and prompted the development of cell cultivation in vitro as a sustainable alternative to harvesting wild plants for their bioactive components. Despite high interest in biotechnological production, little is known about the main factors affecting cell growth and ginsenoside biosynthesis of this species under in vitro conditions. In this study, the potential of cell cultures of P. vietnamensis as a biotechnological source of ginsenosides was was assessed.MethodsSix suspension cell lines that were developed from different sections of a single rhizome through a multi-step culture optimization process and maintained for over 3 years on media with different mineral salt base and varying contents of auxins and cytokinins. These cell lines were evaluated for productivity parameters and cytological characteristics. Ginsenoside profiles were assessed using a combination of the reversed-phase ultra-high-performance liquid chromatography–Orbitrap–tandem mass spectrometry (UHPLC–Orbitrap–MS/MS) and ultra-performance liquid chromatography–time of flight–mass spectrometry (UPLC–TOF–MS).ResultsAll lines demonstrated good growth with a specific growth rate of 0.1–0.2 day−1, economic coefficient of 0.31–0.70, productivity on dry weight (DW) of 0.30–0.83 gDW (L·day)−1, and maximum biomass accumulation varying from 10 to 22 gDW L−1. Ginsenosides of the protopanaxadiol (Rb1, Rb2/Rb3, malonyl-Rb1, and malonyl-Rb2/Rb3), oleanolic acid (R0 and chikusetsusaponin IV), and ocotillol (vinaginsenoside R1) groups and their isomers were identified in cell biomass extracts. Chikusetsusaponin IV was identified in P. vietnamensis cell culture for the first time.DiscussionThese results suggest that suspension cell cultures of Vietnamese ginseng have a high potential for the biotechnological production of biomass containing ginsenosides, particularly of the oleanolic acid and ocotillol groups.

Radiation treatment of food makes it possible to solve some issues of the food industry, including suppression of pathogenic microbial contamination, retention of the nutritional value of the product, and increase in its shelf life. This treatment method in combination with highly sensitive methods of gas chromatography–mass spectrometry makes it possible to reveal biochemical markers of irradiation treatment in meat products with moderate fat content, such as chicken and turkey. This work describes the experimental results of the dependences of the content of volatile organic compounds in chilled chicken meat treated with 1 MeV accelerated electrons with the doses from 250 Gy to 20 kGy in two weeks of storage. The content of volatile organic compounds in irradiated and reference food samples has been determined on days 0, 1, 4, 6, 8, 11, and 13 after irradiation treatment. Similar behavior pattern of aldehydes identified in treated poultry meat, namely, hexanal, heptanal, and pentanal, has been determined in two weeks of product storage. An increase in the aldehyde concentration has been detected in samples treated with doses from 500 Gy to 10 kGy on days 1–4 after irradiation. It has been revealed that, with an increase in the irradiation dose the period of aldehyde accumulation in irradiated meat is displaced toward a shorter period of product storage. Thus, aldehydes can be considered as potential markers of irradiation treatment of chicken meat in the first four days after irradiation.

The impact of substituents at the 4- and 7-positions of 1,10-phenanthroline-2,9-dicarboxamides on the photophysical properties of the ligands and their coordination compounds with the lanthanide triad-europium, gadolinium, and terbium-was analyzed. This study demonstrates how modification of the electronic nature of ligands through the incorporation of diverse functional groups affects the luminescence properties of their complexes. The introduction of various substituents leads to the appearance of intra-ligand or ligand-to-ligand charge transfer (CT) states. The highest luminescence efficiency was observed for LHEu(NO3)3 (Qin = 54.1% and QL = 9.6%), suggesting strong luminescence quenching of the CT state. It was found that a relatively low Delta E (similar to 3000 cm-1) supports direct energy transfer from S1 to T1 bypassing the CT state, even though it is outside Reinhoudt's optimal range. The introduction of fluorines leads to the strongest luminescence quenching among all the substituents. The impact of substituents at the 4- and 7-positions of 1,10-phenanthroline-2,9-dicarboxamides on the photophysical properties of the ligands and their coordination compounds with the triad of lanthanides was analyzed.

Food irradiation is becoming increasingly popular in many countries for preserving and extending the shelf life of foods, which creates a demand for express methods for the detection of absorbed doses. This paper proposes an innovative method for the estimation of the dose absorbed by X-rayed beef samples using a reaction -based optical sensing technique that was proposed earlier by our team for the estimation of the dose absorbed by raw potatoes. Potato and beef samples were exposed to X-ray irradiation at 100 and 1000 Gy and then extracted by water at 23 C-degrees for 24 h or 60/70 C-degrees for 1 h. The resulting solutions were introduced to the reaction mixtures of dyes (carbocyanines, Rhodamines, or Crystal Violet) with oxidants (hypochlorite, bromate, or hydrogen peroxide). The fluorescence intensity and absorbance of the mixtures were periodically measured photographically using visualizers. The data were processed using linear discriminant analysis (LDA) and k -nearest neighbors algorithm (kNN). Using the most efficient individual reactions, the doses can be recognized with a 90-100% accuracy, and the combinations of up to 5 reactions can improve the accuracy to 100%. The protocol is simple and rapid: sample extraction time and indicator reactions take not more than 1 h each. The proposed method potentially has a wide area of applications ranging from plants to animal products.