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Controlled oxidation of methyl‐ketones to aryl glyoxals using Selenium dioxide and iodine is one of the useful transformation. Regardless the availability of many oxidation reagents, Iodine/DMSO system is very efficient and flexible. This system efficiently allows in situ formation of α‐halo ketones and subsequently transforming them directly to useful products. The Iodine/DMSO system allows the selective CI and CO bond formation, substantially useful for converting them to other bond forming reactions and heterocycles useful in the synthetic and medicinal chemistry. Iodine/DMSO system could be an important alternative strategy due to sustainability, metal‐free conditions, allowing multiple/linear domino reactions. This review will focus on heterocyclic systems smartly developed/manipulated by Wu group from methyl‐ketones. The scope and limitations of this method and selected examples of applications for the synthesis of interesting molecules are discussed herein. [ABSTRACT FROM AUTHOR]

Imidazole structures are significant molecular frameworks in pharmaceutical and energetic material research. The synthesis efficiency and yield of their derivatives often vary greatly, making it challenging to establish reaction regularity. In this study, we investigated two types of imidazole derivatives with notably different synthesis efficiencies and yields. Our findings reveal that the catalysis of H2O molecules is crucial for ensuring synthesis efficiency, while side reactions are influenced by the acidity of the solution during the process, thereby affecting the synthesis yield. We observed that the energy barrier for the H2O‐catalyzed ipsilateral H transfer process was reduced to 12.0 from 40.1 kcal/mol, significantly enhancing the reaction efficiency. The synthesis of 34‐dihydroxyimidazolidine‐2‐ketone was found to have a low yield of 19.2% due to competitive side reactions in the reaction system, which have higher energy barriers compared to the desired synthesis pathway. These findings provide a theoretical foundation for future research to optimize the synthesis of imidazole derivatives. Enhancing synthesis conditions could significantly benefit pharmaceutical applications and the development of advanced energetic materials. [ABSTRACT FROM AUTHOR]

This work presents the study results on the acid‐catalyzed cascade condensation of p‐toluenesulfonamide with glyoxal in H2SO4 in order to synthesize aza‐ and oxaazaisowurtzitanes—a platform for promising high‐energy‐density compounds—and explore their formation processes. The effects of the ratio of starting reactants, acidity, reaction medium concentration, and temperature on this process were studied in detail. Five novel compounds were derived, including four oxaazaisowurtzitanes comprising one to three aza groups, and one condensation intermediate. The most favorable conditions for the formation of the resultant caged compounds were established and some new regularities of the process were revealed. For instance, the reaction medium concentration was discovered for the first time to influence the generation process of oxaazaisowurtzitanes via direct condensation. The limiting stage of the cage formation process of oxaazaisowurtzitanes was identified. The formation rate of the oxaazaisowurtzitanes was shown to be dependent on their structure. The factor dramatically reducing the yield of the oxaazaisowurtzitanes at elevated synthesis temperature was also revealed. [ABSTRACT FROM AUTHOR]

Förster resonance energy transfer (FRET) serves as a tool for measuring protein–protein interactions using various sensor molecules. The tension sensor module relies on FRET technology. In our study, this module was inserted within the actinin molecule to measure the surface tension of the cells. Given that the decay curve of FRET efficiency correlates with surface tension increase, precise and accurate efficiency measurement becomes crucial. Among the methods of FRET measurements, FRET efficiency remains the most accurate if sample fixation is successful. However, when cells were fixed with 4% paraformaldehyde (PFA), the actinin-FRET sensor diffused across the cytoplasm; this prompted us to explore fixation method enhancements. Glyoxal fixative has been reported to improve cytoskeletal morphologies compared to PFA. However, it was not known whether glyoxal fits FRET measurements. Glyoxal necessitates an acetic acid solution for fixation; however, acidic conditions could compromise fluorescence stability. We observed that the pH working range of glyoxal fixative aligns closely with MES (methyl-ethylene sulfonic acid) Good's buffer. Initially, we switched the acidic solution for MES buffer and optimized the fixation procedure for in vitro and in vivo FRET imaging. By comparing FRET measurements on hydrogels with known stiffness to tumor nodules in mouse lung, we estimated in vivo stiffness. The estimated stiffness of cancerous tissue was harder than the reported stiffness of smooth muscle. This discovery shed lights on how cancer cells perceive environmental stiffness during metastasis. [ABSTRACT FROM AUTHOR]

BACKGROUND RESULTS CONCLUSION Nε‐carboxymethyllysine (CML), Nε‐carboxyethyllysine (CEL) and α‐aminoadipic acid (AAA) are important foodborne hazards and their intake can cause a variety of diseases in humans. It is extremely important to investigate the formation mechanism of CML, CEL and AAA, as well as their association with each other when aiming to control their production.A multi‐response kinetic model was developed within the glucose‐lysine Maillard reaction model system. The concentrations of glucose, lysine, glyoxal (GO), methylglyoxal (MGO), CML, CEL and AAA were quantified at different temperature (100–160 °C) and at different intervals (0–60 min). The experimental data were fitted to the proposed model to calculate kinetic parameters for the corresponding steps. The results indicated that the production of CML was primarily relied on the direct oxidative cleavage of the Amadori product, rather than the reaction between GO and Lys, whereas CEL and AAA were generated through the reaction of MGO with Lys. Significantly, the reaction between α‐dicarbonyl compounds and Lys preferentially generated CML and CEL, resulting in the lower concentrations of AAA compared to CML and CEL.The multi‐response kinetic model developed in the present study can be applied well to the Maillard reaction. The relationship between the formation mechanisms of CML, CEL and AAA is also explained. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

In biomaterials research, using one or two components to prepare materials is common. However, there is a growing interest in developing materials composed of three components, as these can offer enhanced physicochemical properties compared to those consisting of one or two components. The introduction of a third component can significantly improve the mechanical strength, biocompatibility, and functionality of the resulting materials. Cross-linking is often employed to further enhance these properties, with chemical cross-linking agents being the most widely used method. This article provides an overview of the chemical agents utilized in the cross-linking of three-component biomaterials. The literature review focused on cases where the material was composed of three components and a chemical substance was employed as the cross-linking agent. The most commonly used cross-linking agents identified in the literature include glyoxal, glutaraldehyde, dialdehyde starch, dialdehyde chitosan, and the EDC/NHS mixture. Additionally, the review briefly discusses materials cross-linked with the MES/EDC mixture, caffeic acid, tannic acid, and genipin. Through a critical analysis of current research, this work aims to guide the development of more effective and safer biopolymeric materials tailored for biomedical applications, highlighting potential areas for further investigation and optimization. [ABSTRACT FROM AUTHOR]

Toxicological analyses often necessitate the identification of compounds belonging to diverse functional groups. For GC–MS analyses, derivatization of compounds belonging to different functional groups can pose a challenge and requires the development of comprehensive methods of analysis. One example could be ethylene glycol, whose widespread use is related to possible unintentional or suicidal intoxications. This fact clearly indicates the need to develop sensitive methods for the determination of ethylene glycol and its metabolites in biological material, as only such complex analysis allows for proper toxicological expertise. A simultaneous GC–QqQ–MS/MS method for the determination of ethylene glycol together with its metabolites, glyoxal and glycolic acid, as well as the detection of glyoxylic acid and oxalic acid, was developed and fully validated. A novel approach for simultaneous derivatization of substances from different groups (alcohols, aldehydes, and carboxylic acids) was established. Sample preparation included the addition of three internal standards (BHB-d4, ethylene glycol-d4 and methylglyoxal), precipitation with acetonitrile and subsequent derivatization with N-tert-butyldimethylsilyl-N-methyltrifluoroacetamide (MTBSTFA), as well as pentafluorophenylhydrazine (PFPH). Detection was carried out with the use of triple quadrupole mass spectrometer. The ionization method was electron impact, and quantitative analysis was carried out in multiple reaction monitoring mode. The lower limit of quantification was 1 μg/mL, 0.1 μg/mL, and 500 μg/mL for ethylene glycol, glyoxal, and glycolic acid, respectively. The presented method was applied in three authentic postmortem cases of ethylene glycol intoxication. [ABSTRACT FROM AUTHOR]

This study presents new glyoxal (CHOCHO) products from the Ozone Monitoring Instrument (OMI) by utilizing updated level 1B irradiance/radiance data (Collection 4) and an updated glyoxal retrieval algorithm. The adoption of Collection 4 contributes to the reduction of artificial signals in differential glyoxal slant column densities (dSCDs) and improved fitting root mean square, and the updated retrieval settings result in fewer negative values of glyoxal dSCDs over oceans and less noisy dSCDs in the South Atlantic Anomaly. On‐line calculations of air mass factors consider interactive physical processes between input parameters. To address persistent trends in glyoxal SCDs over the Pacific Ocean that remain despite these updates, a trend correction is implemented. We evaluate the updated OMI glyoxal products using inter‐comparisons with GOME‐2A/2B glyoxal products. OMI glyoxal products exhibit good spatial and temporal agreement with GOME‐2A/2B, with correlation coefficients of 0.75–0.78 globally and 0.84–0.85 over source regions. Small biases are observed in OMI glyoxal vertical column densities, ranging from −0.2 ± 5.7% to 9 ± 3% in low and high glyoxal conditions, respectively, against GOME‐2A/2B. These advancements contribute to the reliability and accuracy of OMI glyoxal products, enhancing their utility for atmospheric studies and enabling a 20‐year‐long data record suitable for climate studies. Plain Language Summary: This research introduces new glyoxal (CHOCHO) products obtained from a satellite instrument called the Ozone Monitoring Instrument (OMI). For new glyoxal products, we use the updated OMI irradiance/radiance data and update the way we analyze the radiance data. As a result, new OMI glyoxal products show the reduction of errors caused by the instrument and consider interactive physical processes between the surface and atmosphere. The new data matches well with similar data from other satellite instruments (GOME‐2A/B), showing that the improvements are effective. This better data set helps scientists study the air quality over a long period of time. Key Points: We improve Ozone Monitoring Instrument (OMI) glyoxal column measurements with the new radiance data (Collection 4) and updated retrieval algorithmThe new glyoxal measurements show the stable spectral fitting through OMI's lifetimeCompared to GOME‐2A/B, OMI glyoxal products show good spatial (temporal) correlation coefficients of 0.75–0.78 (0.84–0.85), respectively [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to investigate the effect on coronavirus disease-2019 (COVID-19) of glyoxal (GO), which is a precursor of advanced glycation end-products, in diabetic and non-diabetic patients, treated in hospital for COVID-19 who were of similar age and disease severity with similar comorbidities. Methods: The study included 57 patients. Measurement of GO was made with the high-performance liquid chromatography method. Results: The GO values were found to be higher in the diabetic group than in the non-diabetic group (p=0.001, p

Aminoacetaldehyde (glycinal, NH2CH2CHO) is a first-generation oxidation product of monoethanolamine (MEA, NH2CH2CH2OH), a solvent widely used for CO2 gas separation, which is proposed as the basis for a range of carbon capture technologies. A complete oxidation mechanism for MEA is required to understand the atmospheric transformation of carbon capture plant emissions, as well as the degradation of this solvent during its use and the oxidative destruction of waste solvent. In this study, we have investigated the •OH radical-initiated oxidation chemistry of aminoacetaldehyde using quantum chemical calculations and RRKM theory/master equation kinetic modeling. This work predicts that aminoacetaldehyde has a tropospheric lifetime of around 6 h and that the reaction predominantly produces the NH2CH2C•O radical intermediate at room temperature, along with minor contributions from NH2•CHCHO and •NHCH2CHO. The dominant radical intermediate NH2CH2C•O is predicted to promptly dissociate to NH2•CH2 and CO, where NH2•CH2 is known to react with O2 under tropospheric conditions to form the imine NH = CH2 + HO2. The NH2•CHCHO radical experiences captodative stabilization and is found to form a weakly bound peroxyl radical upon reaction with O2. Instead, the major oxidation product of NH2•CHCHO and the aminyl radical •NHCH2CHO is the imine NH = CHCHO (+HO2). In the atmosphere, the dominant fate of imine compounds is thought to be hydrolysis, where NH = CH2 will form ammonia and formaldehyde, and NH = CHCHO will produce ammonia and glyoxal. Efficient conversion of the dominant first-generation oxidation products of MEA to ammonia is consistent with field observations and supports the important role of imine intermediates in MEA oxidation. [ABSTRACT FROM AUTHOR]

Context: Carbonyl compounds, especially aldehydes, emitted to the atmosphere, may suffer hydration in aerosols or water droplets in clouds. At the same time, they can react with hydroxyl radicals which may add or abstract hydrogen atoms from these species. The interplay between hydration and hydrogen abstraction is studied using density functional and quantum composite theoretical methods, both in the gas phase and in simulated bulk water. The H-abstraction from the aldehydic and geminal diol forms of formaldehyde, acetaldehyde, glycolaldehyde, glyoxal, methylglyoxal, and acrolein is studied to determine whether the substituent has any noticeable effect in the preference for the abstraction of one form or another. It is found that abstraction of the H-atom adjacent to the carbonyl group gives a more stable radical than same abstraction from the geminal diol in the case of formaldehyde, acetaldehyde, and glycolaldehyde. The presence of a delocalizing group in the Cα (a carbonyl group in glyoxal and methylglyoxal, and a vinyl group in acrolein), reverts this trend, and now the abstraction of the H-atom from the geminal diol gives more stable radicals. A further study was conducted abstracting hydrogen atoms from the other different positions in the species considered, both in the aldehydic and geminal diol forms. Only in the case of glycolaldehyde, the radical formed by H-abstraction from the –CH2OH group is more stable than any of the other radical species. Abstraction of the hydrogen atom in one of the hydroxyl groups in the geminal diol is equivalent to the addition of the •OH radical to the aldehyde. It leads, in some cases, to decomposition into a smaller radical and a neutral molecule. In these cases, some interesting theoretical differences are observed between the results in gas phase and (simulated) bulk solvent, as well as with respect to the method of calculation chosen. Methods: DFT (M06-2X, B2PLYP, PW6B95), CCSD(T), and composite (CBS-QB3, jun-ChS, SCVECV-f12) methods using Dunning basis sets and extrapolation to the CBS limit were used to study the energetics of closed shell aldehydes in their keto and geminal-diol forms, as well as the radical derived from them by hydrogen abstraction. Both gas phase and simulated bulk solvent calculations were performed, in the last case using the Polarizable Continuum Model. [ABSTRACT FROM AUTHOR]

This review summarises the data from long-term experimental studies and literature data on the role of oxidatively modified low-density lipoproteins (LDL) in atherogenesis and diabetogenesis. It was shown that not “oxidized” (lipoperoxide-containing) LDL, but dicarbonylmodified LDL are atherogenic (actively captured by cultured macrophages with the help of scavenger receptors), and also cause expression of lectin like oxidized low density lipoprotein receptor 1 (LOX-1) and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 1 (NOX-1) genes in endotheliocytes, which stimulate apoptosis and endothelial dysfunction. The obtained data allowed us to justify new approaches to pharmacotherapy of atherosclerosis and diabetes mellitus. [ABSTRACT FROM AUTHOR]

We report an efficient synthetic route for the synthesis of tetrahydro indole-2,4-diones from readily available β-enaminones and glyoxal and subsequent I2/DMSO-mediated oxidation/aromatization of tetrahydro indole-2,4-dione to produce 4-hydroxyisatin derivatives. The key aspect of this protocol includes the dual catalytic activity of molecular iodine in the presence of DMSO. Mechanistic study suggested that this reaction is substrate selective as corresponding aromatization and sp3 C–H oxidation stops in the presence of 6,6-disubstituted tetrahydro indole-2,4-dione. Additionally, a thorough investigation into the synthesis of tetrahydro indole-2,4-dione follows acid-catalyzed cyclization/dehydration/enol–keto tautomerism from β-enaminones and glyoxal. [ABSTRACT FROM AUTHOR]

This document provides information on the use of photoacid generators (PAGs) in catalysis, specifically in the Friedel-Crafts alkylation of indoles with aldehydes/ketones. The study focuses on diarylethenes and terarylenes as PAGs, which have advantages such as high quantum yields and autonomy. The researchers developed an environmentally friendly method for synthesizing diindolylmethane derivatives with potential antibacterial, antitumor, and antifungal activities. The document also provides detailed information on the synthesis and characterization of various compounds, including their physical properties and spectroscopic data. This information can be useful for researchers studying these compounds and their properties. [Extracted from the article]

A tandem Cu‐catalyzed oxidation‐intramolecular Cannizzaro reaction leading to bioactive α‐hydroxyesters from α‐hydroxyketones is reported. The process uses oxygen as a sole oxidant to achieve the formation of glyoxals, which are efficiently converted in situ to important α‐hydroxyesters. The mechanistic insights are provided by isotopic labeling and supported by DFT calculations. The transformation proved a robust synthetic tool to achieve the synthesis of human metabolites and hydroxyl esters of various biologically active steroid derivatives. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to investigate the effect on coronavirus disease-2019 (COVID-19) of glyoxal (GO), which is a precursor of advanced glycation end-products, in diabetic and non-diabetic patients, treated in hospital for COVID-19 who were of similar age and disease severity with similar comorbidities. Methods: The study included 57 patients. Measurement of GO was made with the high-performance liquid chromatography method. Results: The GO values were found to be higher in the diabetic group than in the non-diabetic group (p=0.001, p<0.01). The length of stay in hospital was longer in the diabetic group (p=0.017, p<0.05). The white blood cell, neutrophil, neutrophil/lymphocyte ratio, procalcitonin, and ferritin values were determined to be higher in the diabetic group than in the non-diabetic group (p=0.006; p=0.005, p=0.017, p=0.011, p=0.030). Although the mortality and intensive care unit admission rates were similar in the diabetic and non-diabetic patients of similar age with similar comorbidities and COVID-19 severity, the total length of stay in hospital was determined to be longer in the diabetic patients. Together with other inflammation markers, GO, was determined to be higher in the diabetic group. Conclusion: The results of this study showed that elevated GO could be associated with a prolonged recovery time in COVID-19. [ABSTRACT FROM AUTHOR]

More than a century after its initial synthesis, urea-formaldehyde (UF) resins still have dominant applications as adhesives, paints, and coatings. However, formaldehyde in this industry produces formaldehyde emissions that are dangerous to health. Scientists have spent the last decade replacing formaldehyde and phenol with environmentally friendly substances such as glyoxal and tannin to create bio-based adhesives. This review covers recent advances in synthesizing glyoxal tannin-based resins, especially those made from sustainable raw material substitutes and changes made to synthetic processes to improve mechanical properties. The efficacy of using tannin-glyoxal adhesives in producing wood-based composites has been proven. The glyoxylate reaction forms cross-linked bridges between the aromatic sites of the tannin and glyoxal molecular structures. Glyoxal tannin adhesive with a greater percentage of glyoxal than tannin will produce an adhesive with better characteristics. The gel time reduces as the hardener concentration rises from 7.5% to 15% when glyoxal is used in adhesives. However, excessive amounts of glyoxal will result in a decrease in viscosity values. Glyoxal exhibits faster delivery degradation when it reaches a maximum temperature of approximately 130°C, although it initiates the curing process slightly slower at 110°C. Adding glyoxal to tannin-based adhesives can improve the mechanical properties of composite boards. The wet shear strength of the resulting plywood is increased by 105.4% with the addition of 5-weight percent tannin-based resin with glyoxal as a cross-linker in Soy Protein Adhesive. With glyoxal as a hardener, the panels produced showed good internal bond strengths (>0.35 MPa) and met the international standard specifications for interior-grade panels. [ABSTRACT FROM AUTHOR]

Reactive carbonyl species such as methylglyoxal (MGO) act as potent glycating agents that are implicated in several oxidative stress-induced diseases, including, but not limited to, cancer, diabetes and neurodegenerative diseases such as Alzheimer's and Parkinson's diseases. In the present study, a combined approach of initial computational studies and in vitro analysis was utilized to investigate the therapeutic benefit of L-cysteine (CYS), a thiol-containing compound. Based on the reactive analysis using global and local density functional theory (DFT) descriptors, the data reported here has revealed that CYS matches its electron-donating capacity with the electron acceptor, methylglyoxal, making the former a good candidate sequestering agent for the latter. Furthermore, in vitro analysis shows that CYS exhibits significant inhibitory effects towards damaging protein structural alteration and formation of advanced glycation end products (AGEs). Such assessment came about through Congo red binding Assay and Antiglycation Assay using BSA-MGO and BSA-glucose model systems. Additionally, CYS also demonstrates a significant protective effect towards MGO-induced oxidative stress in mouse C2C12 myotubes. Therefore, this thiol-containing compound is a promising therapeutic tool for several glycation or AGEs-induced pathological conditions. The use of more relevant cellular and animal models of desired disease studies is recommended to better understand the mechanistic basis of CYS's potential therapeutic effect. This study utilizing the combined approach of computational and in-vitro analysis, provides helpful data to maximize the potential impact of CYS by designing related molecules that could serve as novel treatment strategies that are effective, safe, and accessible to all in the future. [ABSTRACT FROM AUTHOR]

Introduction: Systemic lupus erythematosus (SLE) is a chronic, autoimmune disease, often characterised by severe course and unclear etiopathogenesis. The reaction of protein glycoxidation, also known as glycation, may be linked to etiopathogenesis of SLE. Advanced glycation end-products (AGEs) exhibit cytotoxic properties, affect cellular signalling, impair functions of extracellular proteins, and may act as neoepitopes. Glucosone (GS), glyoxal (GO), and methylglyoxal (MGO) are examples of α-dicarbonyl compounds (α-DCs) partaking in glycoxidation. The study aimed to evaluate concentrations of these three compounds in blood serum of SLE patients, and to compare the results with healthy individuals. Material and methods: 31 women suffering from SLE and 26 healthy individuals were included in the study. High-performance liquid chromatography with fluorescence detection was applied to evaluate concentrations of α-DCs in their serum samples. Correlations between the results and parameters such as disease duration time, age, glomerular filtration rate (GFR), Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K), and creatinine were analysed. Results: The SLE patients exhibited lower concentrations of glucosone, glyoxal, and methylglyoxal than the control group. Analysis of correlations showed a difference between the examined groups. Conclusions: In women suffering from SLE the course of α-DCs metabolism is altered. SLE patients are characterised by low serum levels of α-DCs. We hypothesise that either hindered proteasomal degradation or fast consumption of α-DCs in oxidative conditions may cause the observed low concentration of these compounds. [ABSTRACT FROM AUTHOR]

Excessive accumulation of advanced glycation end products (AGEs) in the body is associated with diabetes and its complications. In this study, we aimed to explore the potential and mechanism of coffee leaf extract (CLE) in inhibiting the generation of AGEs and their precursors in an in vitro glycation model using bovine serum albumin and glucose (BSA–Glu) for the first time. High‐performance liquid chromatography analysis revealed that CLE prepared with ultrasound pretreatment (CLE‐U) contained higher levels of trigonelline, mangiferin, 3,5‐dicaffeoylquinic acid, and γ‐aminobutyric acid than CLE without ultrasound pretreatment (CLE‐NU). The concentrations of these components, along with caffeine and rutin, were dramatically decreased when CLE‐U or CLE‐NU was incubated with BSA–Glu reaction mixture. Both CLE‐U and CLE‐NU exhibited a dose‐dependent inhibition of fluorescent AGEs, carboxymethyllysine, fructosamine, 5‐hydroxymethylfurfural, 3‐deoxyglucosone, glyoxal, as well as protein oxidation products. Notably, CLE‐U exhibited a higher inhibitory capacity compared to CLE‐NU. CLE‐U effectively quenched fluorescence intensity and increased the α‐helix structure of the BSA–Glu complex. Molecular docking results suggested that the key bioactive compounds present in CLE‐U interacted with the arginine residues of BSA, thereby preventing its glycation. Overall, this research sheds light on the possible application of CLE as a functional ingredient in combating diabetes by inhibiting the generation of AGEs. [ABSTRACT FROM AUTHOR]

Enols—tautomers of ketones or aldehydes—are considered key intermediates in the formation of prebiotic sugars and sugar acids. Although laboratory simulation experiments suggest that enols should be ubiquitous in the interstellar medium, the underlying formation mechanisms of enols in interstellar environments are largely elusive. Here, we present the laboratory experiments on the formation of glyoxal (HCOCHO) along with its ynol tautomer acetylenediol (HOCCOH) in interstellar ice analogs composed of carbon monoxide (CO) and water (H2O) upon exposure to energetic electrons as a proxy for secondary electrons generated from Galactic cosmic rays. Utilizing tunable vacuum ultraviolet photoionization reflectron time-of-flight mass spectrometry, glyoxal and acetylenediol were detected in the gas phase during temperature-programmed desorption. Our results reveal the formation pathways of glyoxal via radical–radical recombination of two formyl (HĊO) radicals, and that of acetylenediol via keto-enol-ynol tautomerization. Due to the abundance of carbon monoxide and water in interstellar ices, glyoxal and acetylenediol are suitable candidates for future astronomical searches. Furthermore, the detection of acetylenediol in astrophysically relevant ices advances our understanding for the formation pathways of high-energy tautomers such as enols in deep space. [ABSTRACT FROM AUTHOR]

Obesity is a complex condition associated with disruptions in carbohydrate, protein, and fat metabolism, linked to increased insulin resistance and glucose intolerance. High levels of Advanced Glycation End-products (AGEs) are associated with a range of chronic diseases, including kidney diseases, diabetic complications, cardiovascular diseases, and neurodegenerative diseases. Our study aims to investigate the accumulation of AGEs in the liver, renal and adipose tissues of mice fed a high-fat diet, contributing to a deeper understanding of obesity and its related metabolic disorders. Our study consists of three different groups fed with diets containing 60% and 10% fat. The Experiment 1 group was maintained on their diet for 12 weeks, while the obese 2 and control groups continued their diets for 24 weeks. AGEs in the liver and kidney tissues obtained were measured using the High-performance liquid chromatography grade (HPLC) method. Higher accumulation of AGEs has been observed in kidney tissue compared to adipose and liver tissues (p < 0.05). Moreover, the GO levels were notably higher in liver tissue than in adipose tissue of the D1 and D2 groups (p < 0.0001). Our results suggest that particularly in kidney tissue, increased filtration burden, functional impairment, and receptor interaction due to obesity may be effective. The lower levels of AGEs detected, especially in the obese groups compared to the control, can be attributed to the inability to metabolize AGEs due to tissue damage caused by obesity. [ABSTRACT FROM AUTHOR]

Abstract This study presents new glyoxal (CHOCHO) products from the Ozone Monitoring Instrument (OMI) by utilizing updated level 1B irradiance/radiance data (Collection 4) and an updated glyoxal retrieval algorithm. The adoption of Collection 4 contributes to the reduction of artificial signals in differential glyoxal slant column densities (dSCDs) and improved fitting root mean square, and the updated retrieval settings result in fewer negative values of glyoxal dSCDs over oceans and less noisy dSCDs in the South Atlantic Anomaly. On‐line calculations of air mass factors consider interactive physical processes between input parameters. To address persistent trends in glyoxal SCDs over the Pacific Ocean that remain despite these updates, a trend correction is implemented. We evaluate the updated OMI glyoxal products using inter‐comparisons with GOME‐2A/2B glyoxal products. OMI glyoxal products exhibit good spatial and temporal agreement with GOME‐2A/2B, with correlation coefficients of 0.75–0.78 globally and 0.84–0.85 over source regions. Small biases are observed in OMI glyoxal vertical column densities, ranging from −0.2 ± 5.7% to 9 ± 3% in low and high glyoxal conditions, respectively, against GOME‐2A/2B. These advancements contribute to the reliability and accuracy of OMI glyoxal products, enhancing their utility for atmospheric studies and enabling a 20‐year‐long data record suitable for climate studies.

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α-Dicarbonyl compounds (α-DCs) are commonly present in various foods. We conducted the investigation into concentration changes of α-DCs including 3-deoxyglucosone (3-DG), glyoxal (GO), and methylglyoxal (MGO) in fresh fruits and decapped commercial juices during storage at room temperature and 4 °C, as well as in homemade juices during storage at 4 °C. The studies indicate the presence of α-DCs in all samples. The initial contents of 3-DG in the commercial juices (6.74 to 65.61 μg/mL) are higher than those in the homemade ones (1.97 to 4.65 μg/mL) as well as fruits (1.58 to 3.33 μg/g). The initial concentrations of GO and MGO are normally less than 1 μg/mL in all samples. During storage, the α-DC levels in the fruits exhibit an initial increase followed by a subsequent decrease, whereas, in all juices, they tend to accumulate continuously over time. As expected, 4 °C storage reduces the increase rates of the α-DC concentrations in most samples. From the viewpoint of the α-DC contents, fruits and homemade juices should always be the first choice for daily intake of nutrients and commercial juices ought to be mostly avoided. [ABSTRACT FROM AUTHOR]

A simple, two‐step process was developed for the easy access of polycyclic pyrrolopyridine derivatives. The first step involves a multicomponent reaction of aryl glyoxal, cyclohexane‐1,3‐dione derivatives and 2‐amino‐1,4‐napthoquinone in AcOH: H2O (1 : 1 v/v) under reflux conditions which led to the formation of 1,5‐diketones in 15 min of reaction time. In the second step, the reaction of ammonium acetate with 1,5‐diketones in AcOH under reflux conditions resulted the formation of polycyclic pyrrolopyridine derivatives. All the products were characterized by FTIR, 1H NMR, 13C NMR and HRMS. The single crystal XRD of one compound was recorded to further confirm the structure of the product. The presence of several bioactive moieties in our product, simple reaction process, metal‐free reaction conditions, easy purification method, and good yields of the products are the notable features of this methodology. [ABSTRACT FROM AUTHOR]

Lactobacillus fermentum (L. fermentum) was first evaluated as a potential advanced glycation end-product (AGE) formation inhibitor by establishing a bovine serum albumin (BSA) + glucose (glu) glycation model in the present study. The results showed that the highest inhibition rates of pentosidine and total fluorescent AGEs by L. fermentum were approximately 51.67% and 77.22%, respectively, which were higher than that of aminoguanidine (AG). Mechanistic analysis showed that L. fermentum could capture methylglyoxal and glyoxal, inhibit carbonyl and sulfhydryl oxidation, reduce the binding of glucose and amino groups, increase total phenolic content and antioxidant activity, and release intracellular substances to scavenge free radicals; these abilities were the basis of the antiglycation mechanism of L. fermentum. In addition, L. fermentum significantly prevented conformational changes in proteins during glycation, reduced protein cross-linking by 35.67%, and protected the intrinsic fluorophore. Therefore, the inhibition of L. fermentum on glycation mainly occurs through antioxidation, the capture of dicarbonyl compounds, and the protection of the BSA structure. These findings collectively suggest that Lactobacillus is an inhibitor of protein glycation and AGE formation and has the potential for nutraceutical applications. [ABSTRACT FROM AUTHOR]

The reaction of carbonyl-to-imine/hemiaminal conversion in the atmospheric aqueous phase is a critical pathway to produce the light-absorbing N-containing secondary organic compounds (SOC). The formation mechanism of these compounds has been wildly investigated in bulk solutions with a low ionic strength. However, the ionic strength in the aqueous phase of the polluted atmosphere may be higher. It is still unclear whether and to what extent the inorganic ions can affect the SOC formation. Here we prepared the bulk solution with certain ionic strength, in which glyoxal and ammonium were mixed to mimic the aqueous-phase reaction. Molecular characterization by High-resolution Mass Spectrometry was performed to identify the N-containing products, and the light absorption of the mixtures was measured by ultraviolet-visible spectroscopy. Thirty-nine N-containing compounds were identified and divided into four categories (N-heterocyclic chromophores, high-molecular-weight compounds with N-heterocycle, aliphatic imines/hemiaminals, and the unclassified). It was observed that the longer reaction time and higher ionic strength led to the formation of more N-heterocyclic chromophores and the increasing of the light-absorbance of the mixture. The added inorganic ions were proposed to make the aqueous phase somewhat viscous so that the molecules were prone to undergo consecutive and intramolecular reactions to form the heterocycles. In general, this study revealed that the enhanced ionic strength and prolonged reaction time had the promotion effect on the light-absorbing SOC formation. It implies that the aldehyde-derived aqueous-phase SOC would contribute more light-absorbing particulate matter in the industrial or populated area where inorganic ions are abundant. [Display omitted] [ABSTRACT FROM AUTHOR]

Objective: Advanced glycation end‐products (AGEs) represent a large group of compounds generated by a non‐enzymatic reaction between reducing sugars and amino groups. The formation and accumulation of AGEs in the skin lead to protein crosslinking, dermal stiffening and yellowing, which ultimately contribute to cutaneous ageing. Amino acids have been described to exhibit anti‐glycation effects. The objective of this study was to understand the inhibitory role of the amino acid derivative N‐acetyl‐L‐hydroxyproline (NAHP) as an anti‐glycation active for human skin. Methods: A cell‐free assay investigating the inhibition of glycation of serum albumin by NAHP was used to determine the capability of NAHP to decrease AGE formation. Also, by assessing the amount of the AGE N‐(carboxymethyl)lysine (CML) the anti‐glycation abilities of NAHP were investigated utilizing dot blot analysis. The improvement of cell–matrix interaction by NAHP was determined in vitro using a glycated fibroblast‐populated collagen lattice (FPCL) dermis model. In skin biopsies, AGE autofluorescence was determined after treatment with NAHP and/or glucose ex vivo. Results: NAHP significantly and dose‐dependently inhibited levels of AGEs, which were induced by the glycation of a protein solution. This decrease could be visualized by showing that the brownish appearance as well as the AGE‐specific fluorescence of glucose‐treated samples were reduced after the application of increasing amounts of NAHP. Also, CML formation was dose‐dependently inhibited by NAHP. In FPCLs, the contractile capacity of fibroblasts was significantly disturbed after glycation. This could be prevented by the addition of NAHP. Compared to glyoxal‐treated samples, the co‐application of NAHP significantly decreased the diameter as well as the weight of glycated FPCLs. Ex vivo application of glucose to skin explants showed a higher AGE fluorescence signal compared to control explants. Co‐treatment with NAHP and glucose decreased the level of AGE fluorescence in comparison to glucose‐treated explants. Conclusion: These data provide clear evidence that under glycation stress conditions treatment with NAHP inhibited AGE formation in vitro and ex vivo and prevented the loss of cellular contractile forces in a glycated dermis model. Thus, NAHP obviously provides a beneficial treatment option to counteract AGE‐related changes in human skin such as dermal stiffening and yellowish skin appearance. [ABSTRACT FROM AUTHOR]

α-Dicarbonyls are significant degradation products resulting from the Maillard reaction during food processing. Their presence in foods can indicate the extent of heat exposure, processing treatments, and storage conditions. Moreover, they may be useful in providing insights into the potential antibacterial and antioxidant activity of U.S. honey. Despite their importance, the occurrence of α-dicarbonyls in honey produced in the United States has not been extensively studied. This study aims to assess the concentrations of α-dicarbonyls in honey samples from different regions across the United States. The identification and quantification of α-dicarbonyls were conducted using reverse-phase liquid chromatography after derivatization with o-phenylenediamine (OPD) and detected using ultraviolet (UV) and mass spectrometry methods. This study investigated the effects of pH, color, and derivatization reagent on the presence of α-dicarbonyls in honey. The quantification method was validated by estimating the linearity, precision, recovery, method limit of detection, and quantification using known standards for GO, MGO, and 3-DG, respectively. Three major OPD-derivatized α-dicarbonyls including methylglyoxal (MGO), glyoxal (GO), and 3-deoxyglucosone (3-DG), were quantified in all the honey samples. 3-Deoxyglucosone (3-DG) was identified as the predominant α-dicarbonyl in all the U.S. honey samples, with concentrations ranging from 10.80 to 50.24 mg/kg. The total α-dicarbonyl content ranged from 16.81 to 55.74 mg/kg, with the highest concentration measured for Southern California honey. Our results showed no significant correlation between the total α-dicarbonyl content and the measured pH solutions. Similarly, we found that lower amounts of the OPD reagent are optimal for efficient derivatization of MGO, GO, and 3-DG in honey. Our results also indicated that darker types of honey may contain higher α-dicarbonyl content compared with lighter ones. The method validation results yielded excellent recovery rates for 3-DG (82.5%), MGO (75.8%), and GO (67.0%). The method demonstrated high linearity with a limit of detection (LOD) and limit of quantitation (LOQ) ranging from 0.0015 to 0.002 mg/kg and 0.005 to 0.008 mg/kg, respectively. Our results provide insights into the occurrence and concentrations of α-dicarbonyl compounds in U.S. honey varieties, offering valuable information on their quality and susceptibility to thermal processing effects. [ABSTRACT FROM AUTHOR]

Described herein is an effective and green reaction between diketones, amines and bio‐renewable glyoxal, affording a wide range of 2‐pyrrolin‐5‐ones and releasing water as the only byproduct. The reaction features step‐economy, high efficiency, mild conditions, broad substrate scope, hazardous waste avoiding and easy scale‐up. The further transformation between the products and aldehydes can be potentially applied for fluorescent dye synthesis. [ABSTRACT FROM AUTHOR]

The Geostationary Environment Monitoring Spectrometer (GEMS) aboard the GEO-KOMPSAT-2B satellite is the first geostationary satellite launched to monitor the environment. GEMS conducts hourly measurements during the day over East and Southeast Asia. This work presents glyoxal (CHOCHO) vertical column densities (VCDs) retrieved from GEMS, with optimal settings for glyoxal retrieval based on sensitivity tests involving reference spectrum sampling and fitting window selection. We evaluated GEMS glyoxal VCDs by comparing them to TROPOMI and MAX-DOAS groundbased observations. On average, GEMS and TROPOMI VCDs show a spatial correlation coefficient of 0.63, increasing to 0.87 for Northeast Asia. While GEMS and TROPOMI demonstrate similar monthly variations in the Indochinese peninsula regions (R > 0.67), variations differ in other areas. Specifically, GEMS VCDs are lower in the summer and higher in the winter than TROPOMI VCDs in Northeast Asia, potentially due to a polluted reference spectrum and high NO2 concentrations. This trend also occurs in comparing monthly variations between GEMS and MAX-DOAS VCDs. When averaged hourly, GEMS and MAX-DOAS VCDs exhibit similar diurnal variations, especially at stations in Japan (Chiba, Kasuga, and Fukue). [ABSTRACT FROM AUTHOR]

The addition of various chemical modifications to RNA introduces an additional layer of complexity to the regulation of gene expression. Among all RNA modifications, N6‐methyladenosine (m6A) has earned its status as the most abundant and well‐studied post‐transcriptional modification in mammalian mRNA. Nevertheless, understanding the role of m6A in shaping the fate of RNA molecules and its influence on gene expression heavily depends on the development and application of detection technologies. Among all m6A detection methods, chemical‐based sequencing methods show unique advantages. Our group recently developed an absolute quantification method named GLORI, which employs nitrite and glyoxal to convert adenosine to inosine efficiently. With its potential to emerge as the gold standard for m6A detection, GLORI showcases the promise of nitrite‐based approaches. This review provides a comprehensive overview of m6A detection techniques based on deamination or nitrosation, evaluating their strengths and limitations. Furthermore, we offer insights into the future directions of innovative approaches in m6A profiling. [ABSTRACT FROM AUTHOR]

Background. Interest in natural polymers is due to the expansion of their practical use. An obstacle on this path is the lack of information about their hydration time, solubility at high temperatures, etc. Purpose. Increasing the hydration properties of carboxymethyl starch by cross-linking its molecules with dialdehyde. Identification of conditions for obtaining carboxymethyl starch with improved properties, study of the physicochemical and colloidal properties of the resulting compound. Methodology. The hydration properties of carboxymethyl starch were increased by treatment with a glyoxal solution. The amount of bound glyoxal in the product was analyzed by gravimetry. Solubility in water - using a rotational viscometer. Originality. The conditions for obtaining carboxymethyl starch with increased hydration properties have been identified. Findings. Using the hydrostatic amplification method, it was revealed that the minimum amount of gloxal used to accelerate the dissolution process is 0.06-0.19 equiv. The conditions for increasing bound gloxal, necessary to achieve viscosity (95%) and high results in obtaining the product when drying at 40- 78°C, were identified. [ABSTRACT FROM AUTHOR]

The aqueous-phase chemistry of glyoxal (GL) with reduced nitrogen compounds (RNCs) is a significant source for secondary brown carbon (SBrC), which is one of the largest uncertainties in climate predictions. However, a few studies have revealed that SBrC formation is affected by multifunctional RNCs, which have a non-negligible atmospheric abundance. Hence, we assessed theoretical and experimental approaches to investigate the reaction mechanisms and kinetics of the mixtures for ammonium sulfate (AS), multifunctional amine monoethanolamine (MEA), and GL. Our experiments indicate that light absorption and growth rate are enhanced more efficiently in the MEA–GL mixture relative to AS–GL and MEA–AS–GL mixtures and MEA reactions of the chromophores than in the analogous AS reactions. Quantum chemical calculations show that the formation and propagation of oligomers proceed via four-step nucleophilic addition reactions in three reaction systems. The presence of MEA provides the two extra branched chains that affect the natural charges and steric hindrance of intermediates, facilitating the formation of chromophores. Molecule dynamics simulations reveal that the interfacial and interior attraction on the aqueous aerosols with MEA is more pronounced for small α -dicarbonyls to facilitate further engagement in the aqueous-phase reactions. Our results show a possible missing source for SBrC formation on urban, regional, and global scales. [ABSTRACT FROM AUTHOR]

Glyoxal, methylglyoxal, and diacetyl are toxic α-dicarbonyl compounds found in heat-processed foods, including edible oils. Dispersive liquid–liquid microextraction was combined with gas chromatography mass spectrometry to determine the glyoxal, methylglyoxal, and diacetyl contents in sesame oil. Chloroform and methanol were selected as the optimal extraction and dispersive solvents, respectively. The maximum derivatization efficiency was obtained using 500 µg of the derivatization agent, o-phenylenediamine. The derivatization of glyoxal was completed in 1 h, whereas those of methylglyoxal and diacetyl were completed immediately. The optimized method was validated, and was found to exhibit a good linearity, recovery, intraday repeatability, and interday reproducibility. The α-dicarbonyl compound concentrations in the oils were dependent on the roasting temperature. The sesame oil concentrates contained 0–175.4, 0–990.5, and 0–220.9 ng g−1 of glyoxal, methylglyoxal, and diacetyl, respectively. For the perilla oils, the respective concentrations were 0–96.4, 0–410.8, and 0–197.5 ng g−1.

Introduction Systemic lupus erythematosus (SLE) is a chronic, autoimmune disease, often characterised by severe course and unclear etiopathogenesis. The reaction of protein glycoxidation, also known as glycation, may be linked to etiopathogenesis of SLE. Advanced glycation end-products (AGEs) exhibit cytotoxic properties, affect cellular signalling, impair functions of extracellular proteins, and may act as neoepitopes. Glucosone (GS), glyoxal (GO), and methylglyoxal (MGO) are examples of α-dicarbonyl compounds (α-DCs) partaking in glycoxidation. The study aimed to evaluate concentrations of these three compounds in blood serum of SLE patients, and to compare the results with healthy individuals. Material and methods 31 women suffering from SLE and 26 healthy individuals were included in the study. High-performance liquid chromatography with fluorescence detection was applied to evaluate concentrations of α-DCs in their serum samples. Correlations between the results and parameters such as disease duration time, age, glomerular filtration rate (GFR), Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K), and creatinine were analysed. Results The SLE patients exhibited lower concentrations of glucosone, glyoxal, and methylglyoxal than the control group. Analysis of correlations showed a difference between the examined groups. Conclusions In women suffering from SLE the course of α-DCs metabolism is altered. SLE patients are characterised by low serum levels of α-DCs. We hypothesise that either hindered proteasomal degradation or fast consumption of α-DCs in oxidative conditions may cause the observed low concentration of these compounds.

The reactions of glyoxal (CHO)2) with amines in cloud processes contribute to the formation of brown carbon and oligomer particles in the atmosphere. However, their molecular mechanisms remain unknown. Herein, we investigate the ammonolysis mechanisms of glyoxal with amines at the air‐water nanodroplet interface. We identified three and two distinct pathways for the ammonolysis of glyoxal with dimethylamine and methylamine by using metadynamics simulations at the air‐water nanodroplet interface, respectively. Notably, the stepwise pathways mediated by the water dimer for the reactions of glyoxal with dimethylamine and methylamine display the lowest free energy barriers of 3.6 and 4.9 kcal ⋅ mol−1, respectively. These results showed that the air‐water nanodroplet ammonolysis reactions of glyoxal with dimethylamine and methylamine were more feasible and occurred at faster rates than the corresponding gas phase ammonolysis, the OH+(CHO)2 reaction, and the aqueous phase reaction of glyoxal, leading to the dominant removal of glyoxal. Our results provide new and important insight into the reactions between carbonyl compounds and amines, which are crucial in forming nitrogen‐containing aerosol particles. [ABSTRACT FROM AUTHOR]

A highly sensitive and selective fluorescence method has been conducted for the detection of Hg2+ based on aminophenylboronic acid–modified carboxyl magnetic beads (CMB@APBA) and CRISPR/Cas12a system mediated by glyoxal caged nucleic acid (gcDNA). As a bi-functional DNA linker, gcDNA offers advantages of simultaneous recognition by boronic acid and complementary DNA/RNA. Under acidic condition, gcDNA can be immobilized on CMB@APBA through the formation of borate ester bond. The formed boric acid–esterified gcDNA can further bind with complementary CRISPR RNA through A-T base pairing to activate Cas12a with kcat/Km ratio of 3.4 × 107 s−1 M−1, allowing for amplified signal. Hg2+ can specifically combine with CMB@APBA, resulting in the release of gcDNA from CMB@APBA and the following inhibition on the activation of CRISPR/Cas12a system around magnetic bead. Under optimal conditions, the method exhibits a linear range from 20 to 250 nM, with a detection limit of 2.72 nM. The proposed method can detect Hg2+ in milk and tea beverages, providing a great significance for on-site monitoring of Hg2+ contamination in food. [ABSTRACT FROM AUTHOR]

BACKGROUND: Lotus rhizome juice (LRJ) is susceptible to the Maillard reaction (MR) and caramelization, which tend to cause a reduction in quality and lower consumer acceptance of the product. 1,2‐Dicarbonyl compounds (DCs) and heterocyclic compounds have attracted increasing attention as key intermediates responsible for the formation of brown pigments during MR and caramelization. However, little is known about the effects of these two types of compounds on brown pigments in LRJ during sterilization. This study quantified the changes in brown intensity (A420), DCs, and heterocyclic compounds before and after spiking, and identified the precursors and intermediates for brown pigment formation as well as the formation pathways of the intermediates. RESULTS: The spiking experiments suggested that spiking with fructose resulted in more 3‐deoxyglucosone (3‐DG) and 2,3‐dihydro‐3,5‐dihydroxy‐6‐methyl‐4(H)‐pyran‐4‐one (DDMP), while that with lysine led to more glucosone (GS) and 2,3‐butanedione (2,3‐BD) in LRJ. The addition of glucose, asparagine, and glutamine promoted the formation of 5‐hydroxymethylfurfural (HMF) significantly, whereas the addition of glucose, lysine, and asparagine resulted in more norfuraneol. Spiking with reducing sugars and amino acids promoted both glyoxal (GO) and methylglyoxal (MGO), and the effect of glucose on GO was particularly significant. Correlation analysis showed that A420 had the highest correlation with 3‐DG in the fructose‐ and lysine‐spiked group, and with HMF in the glucose‐, asparagine‐, and glutamine‐spiked groups. CONCLUSION: This study revealed that fructose, glucose, asparagine, glutamine, and lysine were essential precursors of MR and caramelization in LRJ during sterilization. 3‐Deoxyglucosone and DDMP were mainly produced by caramelization with fructose as the primary precursor, whereas GS and 2,3‐BD were primarily formed via MR with lysine catalysis. The MR and caramelization were the main formation pathways of HMF (catalyzed by asparagine and glutamine) and norfuraneol (catalyzed by lysine and asparagine), with glucose as the critical precursor. Methylglyoxal was mainly produced by MR or caramelization, and caramelization was the main formation pathway of GO, with glucose as the precursor. Dor brown pigment formation from fructose and lysine, 3‐DG was identified as the most crucial intermediate, while for that from glucose, asparagine, and glutamine, HMF was found to be the most important intermediate. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The application of most chemical fixatives, such as formalin, in the anatomic pathology laboratory requires safety training and hazardous chemical monitoring due to the toxicity and health risks associated with their use. Consequently, the use of formalin has been banned in most applications in Europe; the primary exception is its use in the histology laboratory in lieu of a suitable and safer alternative. Glyoxal based solutions, several of which are available commercially, are the most promising alternative fixatives, because they are based on a mechanism of fixation similar to that of formalin. Unlike formalin, however, glyoxal based solutions do not dissociate from water and therefore do not require ventilation measures such as a fume hood. A primary barrier to the adoption of commercially available glyoxal based solutions is their low pH, which can produce undesirable morphological and antigenic tissue alterations; however, a recently available neutral pH glyoxal product (glyoxal acid free) (GAF) has been developed to mitigate the challenges of low pH. We compared the morphology and histochemistry among tissues fixed in 10% neutral buffered formalin, a commercially available acidic glyoxal product (Prefer), and GAF. Tissues fixed in formalin and Prefer exhibited similar morphology and staining properties; tissues fixed with 2% GAF exhibited deleterious effects. [ABSTRACT FROM AUTHOR]

This article provides a detailed exploration of the preparation of dichloroglyoxime (DCG), a compound with various industrial applications. It discusses different methods for preparing DCG, emphasizing the importance of accurately controlling the amount of chlorine gas used in the reaction. The article also highlights the synthesis of glyoxime, the precursor to DCG, and the safety precautions that should be taken during the preparation process. The authors provide detailed instructions for obtaining high yields of pure DCG and discuss the mechanism of chlorination and decomposition of the products. The article aims to benefit researchers in need of these reactive compounds. [Extracted from the article]

Soy protein isolate (SPI) has garnered researchers' attention due to its abundance, costeffectiveness, excellent biocompatibility, hemo-compatibility, and biodegradability. However, SPI faces limitations in application due to poor processability and weak mechanical strength. Substantial efforts have been made to address these challenges. In this preliminary study, glycerol and biofibers were added to SPI to improve the mechanical properties and film forming, and glyoxal was employed to crosslink SPI molecules. The microstructure and mechanical properties of the resulting SPI/composite films were evaluated. A 15% addition of glycerol proved sufficient for good film formation. Among the biofibers, short SF microfibers were the most effective in enhancing breaking strength, while TEMPO-oxidized CNF (cellulose nanofiber) excelled among CNFs. Crosslinking with glyoxal significantly enhanced the mechanical properties, with the type of biofiber minimally affecting the mechanical properties of the crosslinked SPI composite films. [ABSTRACT FROM AUTHOR]

Glyoxal (CHOCHO) is a trace gas in the atmosphere, often used as an indicator of biogenic emissions. It is frequently compared to formaldehyde concentrations, which serve as indicators of anthropogenic emissions, to gain insights into the characteristics of the environmental source. This study employed broadband cavity-enhanced absorption spectroscopy to detect gaseous CHOCHO, methylglyoxal, and NO2. Two different detection methods are compared. Spectrograph and CCD Detection: This approach involves coupling the system to a spectrograph with a charge-coupled device (CCD) detector. It achieved a 1 min 1-σ detection limit of 2.5 × 108 molecules/cm3, or 10 parts per trillion (ppt). Methylglyoxal and NO2 achieved 1 min 1-σ detection limits of 34 ppt and 22 ppt, respectively. Interferometer and PMT Detection: In this method, an interferometer is used in conjunction with a photomultiplier tube (PMT) detector. It resulted in a 2 min 1-σ detection limit of 1.5 × 1010 molecules/cm3, or 600 ppt. The NO2 2 min 1-σ detection limit was determined to be 900 ppt. Concentrations of methylglyoxal were difficult to determine using this method, as they appeared to be below the detection limit of the instrument. This study discusses the advantages and limitations of each of these detection methods. [ABSTRACT FROM AUTHOR]

"Heptil" (unsymmetrical dimethylhydrazine—UDMH) is extensively employed worldwide as a propellant for rocket engines. However, UDMH constantly loses its properties as a result of its continuous and uncontrolled absorption of moisture, which cannot be rectified. This situation threatens its long-term usability. UDMH is an exceedingly toxic compound (Hazard Class 1), which complicates its transportation and disposal. Incineration is currently the only method used for its disposal, but this process generates oxidation by-products that are even more toxic than the original UDMH. A more benign approach involves its immediate reaction with a formalin solution to form 1,1–dimethyl-2-methylene hydrazone (MDH), which is significantly less toxic by an order of magnitude. MDH can then be polymerized under acidic conditions, and the resulting product can be burned, yielding substantial amounts of nitrogen oxides. This review seeks to shift the focus of MDH from incineration towards its application in the synthesis of relatively non-toxic and readily available analogs of various pharmaceutical substances. We aim to bring the attention of the international chemical community to the distinctive properties of MDH, as well as other hydrazones (such as glyoxal, acrolein, crotonal, and meta-crolyl), wherein each structural fragment can initiate unique transformations that have potential applications in molecular design, pharmaceutical research, and medicinal chemistry. [ABSTRACT FROM AUTHOR]

An important drug used in the treatment of Parkinson's disease is amantadine. We are the first to perform a comprehensive study based on various glycation and oxidation factors, determining the impact of amantadine on protein glycoxidation. Sugars (glucose, fructose, galactose) and aldehydes (glyoxal, methylglyoxal) were used as glycation agents, and chloramine T was used as an oxidant. Glycoxidation biomarkers in albumin treated with amantadine were generally not different from the control group (glycation/oxidation factors), indicating that the drug did not affect oxidation and glycation processes. Molecular docking analysis did not reveal strong binding sites of amantadine on the bovine serum albumin structure. Although amantadine poorly scavenged hydroxyl radical and hydrogen peroxide, it had significantly lower antioxidant and antiglycation effect than all protein oxidation and glycation inhibitors. In some cases, amantadine even demonstrated glycoxidant, proglycation, and prooxidant properties. In summary, amantadine exhibited weak antioxidant properties and a lack of antiglycation activity. [ABSTRACT FROM AUTHOR]

We developed a sequential intramolecular ring‐closure‐opening‐closure pathway using a catalyst‐free and organo‐base catalyzed system for the synthesis of fused regioselective tricyclic furo[3,2‐c]chromen and bicyclic imidazo[1,2‐a]pyridine via a one‐pot three‐component reaction. The protocol involved a Knoevenagel and Michael adduct via intramolecular cyclization with 4‐hydroxycoumarin, aromatic glyoxal, and 2‐aminopyridine under heating and ambient conditions with very good yields. The merits of this methodology were studied, and new practical ways were developed to access furo[3,2‐c]chromen and imidazo[1,2‐a]pyridine moieties. [ABSTRACT FROM AUTHOR]

The contents of free and protein-bound advanced glycation end-products (AGEs) including Nε-carboxymethyllysine (CML) and Nε-carboxyethyllysine (CEL), along with glyoxal (GO), methylglyoxal (MGO), chemical components, and salt in commercially prepared and prefabricated fish products were analyzed. Snack food classified as commercially prepared products exhibited higher levels of GO (25.00 ± 3.34–137.12 ± 25.87 mg/kg of dry matter) and MGO (11.47 ± 1.39–43.23 ± 7.91 mg/kg of dry matter). Variations in the contents of free CML and CEL increased 29.9- and 73.0-fold, respectively. Protein-bound CML and CEL in commercially prepared samples were higher than those in raw prefabricated ones due to the impact of heat treatment. Levels of GO and MGO demonstrated negative correlations with fat (R = −0.720 and −0.751, p < 0.05) in commercially prepared samples, whereas positive correlations were observed (R = 0.526 and 0.521, p < 0.05) in raw prefabricated ones. The heat-induced formation of protein-bound CML and CEL showed a negative correlation with the variations of GO and MGO but was positively related to protein levels in prefabricated products, suggesting that GO and MGO may interact with proteins to generate AGEs during heating. The influence of NaCl on the formation of GO and MGO exhibited variations across different fish products, necessitating further investigation. [ABSTRACT FROM AUTHOR]

This review summarises the data from long-term experimental studies and literature data on the role of oxidatively modified low-density lipoproteins (LDL) in atherogenesis and diabetogenesis. It was shown that not “oxidized” (lipoperoxide-containing) LDL, but dicarbonyl-modified LDL are atherogenic (actively captured by cultured macrophages with the help of scavenger receptors), and also cause expression of lectin like oxidized low density lipoprotein receptor 1 (LOX-1) and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 1 (NOX-1) genes in endotheliocytes, which stimulate apoptosis and endothelial dysfunction. The obtained data allowed us to justify new approaches to pharmacotherapy of atherosclerosis and diabetes mellitus.