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Molecules (Basel, Switzerland) Jun 2024In this work, we synthesized and confirmed the structure of several alkaloid N-oxides using mass spectrometry and Fourier-transform infrared spectroscopy. We also...
In this work, we synthesized and confirmed the structure of several alkaloid N-oxides using mass spectrometry and Fourier-transform infrared spectroscopy. We also investigated their reduction mechanisms using voltammetry. For the first time, we obtained alkaloid N-oxides using an oxidation reaction with potassium peroxymonosulfate as an oxidant. The structure was established based on the obtained fragmentation mass spectra recorded by LC-Q-ToF-MS. In the FT-IR spectra of the alkaloid N-oxides, characteristic signals of N-O group vibrations were recorded (bands in the range of 928 cm⁻ to 971 cm⁻), confirming the presence of this functional group. Electrochemical reduction studies demonstrated the reduction of alkaloid N-oxides at mercury-based electrodes back to the original form of the alkaloid. For the first time, the products of the electrochemical reduction of alkaloid N-oxides were detected by mass spectrometry. The findings provide insights into the structural characteristics and reduction behaviors of alkaloid N-oxides, offering implications for pharmacological and biochemical applications. This research contributes to a better understanding of alkaloid metabolism and degradation processes, with potential implications for drug development and environmental science.
Topics: Alkaloids; Oxides; Spectroscopy, Fourier Transform Infrared; Oxidation-Reduction; Electrochemical Techniques; Molecular Structure; Mass Spectrometry; Electrodes
PubMed: 38930787
DOI: 10.3390/molecules29122721 -
Materials (Basel, Switzerland) Jun 2024Ceramic matrix composites (CMCs) could be a game changer in the aero-engine industry. Their density is circa one-third of their metallic counterpart. CMCs, furthermore,...
Ceramic matrix composites (CMCs) could be a game changer in the aero-engine industry. Their density is circa one-third of their metallic counterpart. CMCs, furthermore, offer increased strength and greater capability at very high temperatures. This would allow for a reduction in cooling and an increased engine performance. Some challenges, besides the complexity of the manufacturing process, however, remain for the structural integrity of this technology. CMCs are inherently brittle; furthermore, they tend to oxidise when attacked by water or oxygen, and their constituents become brittle and more prone to failure. There are two main points of novelty proposed by this work. The first one is to model and reproduce recent oxidation experimental data with a simple Fick's law implemented in Abaqus. The parameters of this modelling are a powerful tool for the design of such material systems. The second aspect consists in the development of a new computational framework for iteratively calculating oxygen diffusion and stiffness degradation of the material. Oxidation and stiffness degradation are in fact coupled phenomena. The crack (or microcracking) opening, the function of applied stress, accelerates oxygen diffusion whilst the oxidation diffusion itself contributes to embrittlement and then damage introduction in the material system.
PubMed: 38930402
DOI: 10.3390/ma17123034 -
Antioxidants (Basel, Switzerland) May 2024Oxidation-reduction post-translational modifications (redox-PTMs) are chemical alterations to amino acids of proteins. Redox-PTMs participate in the regulation of... (Review)
Review
Oxidation-reduction post-translational modifications (redox-PTMs) are chemical alterations to amino acids of proteins. Redox-PTMs participate in the regulation of protein conformation, localization and function, acting as signalling effectors that impact many essential biochemical processes in the cells. Crucially, the dysregulation of redox-PTMs of proteins has been implicated in the pathophysiology of numerous human diseases, including neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. This review aims to highlight the current gaps in knowledge in the field of redox-PTMs biology and to explore new methodological advances in proteomics and computational modelling that will pave the way for a better understanding of the role and therapeutic potential of redox-PTMs of proteins in neurodegenerative diseases. Here, we summarize the main types of redox-PTMs of proteins while providing examples of their occurrence in neurodegenerative diseases and an overview of the state-of-the-art methods used for their detection. We explore the potential of novel computational modelling approaches as essential tools to obtain insights into the precise role of redox-PTMs in regulating protein structure and function. We also discuss the complex crosstalk between various PTMs that occur in living cells. Finally, we argue that redox-PTMs of proteins could be used in the future as diagnosis and prognosis biomarkers for neurodegenerative diseases.
PubMed: 38929122
DOI: 10.3390/antiox13060681 -
Antioxidants (Basel, Switzerland) May 2024Oxidative stress (OS) affects men's health and impairs spermatogenesis. Micronutrient antioxidants are available for male infertility as complemental support; however,...
Oxidative stress (OS) affects men's health and impairs spermatogenesis. Micronutrient antioxidants are available for male infertility as complemental support; however, their efficacy remains debatable. This study aimed to investigate whether antioxidants can help to reduce sperm OS and improve semen analysis and quality. We included 171 male partners of couples planning to undergo assisted reproductive technology (ART). Male partners, aged 29-41 years, of couples intending to conceive were self-selected to take daily antioxidants (n = 84) containing folic acid and zinc, or not to take antioxidants (n = 52) for 6 months. We analyzed the alterations in serum oxidant levels, sperm parameters, OS, and deoxyribonucleic acid fragmentation after 3 and 6 months. Additionally, implantation, clinical pregnancy, and miscarriage rates after vitrified-warmed embryo transfer were compared between those taking antioxidants and those not taking them after 6 months. In men with high static oxidation-reduction potential (sORP), we observed a significant improvement in sperm concentration and sORP. The high-quality blastocyst rate tended to increase, and implantation and clinical pregnancy rates also significantly increased after 6 months of intervention. The micronutrient antioxidants could improve sperm function by reducing OS and improving ART outcomes. Therefore, micronutrient antioxidants may be a viable treatment option for male infertility.
PubMed: 38929074
DOI: 10.3390/antiox13060635 -
International Journal of Molecular... Jun 2024The oxidative esterification of aldehydes under mild conditions remains a significant challenge. This study introduces a unique defective UiO-66 to achieve gold...
The oxidative esterification of aldehydes under mild conditions remains a significant challenge. This study introduces a unique defective UiO-66 to achieve gold nanoclusters (AuNCs) for efficient aldehyde oxidation under mild conditions. The construction and characterization of these materials are thoroughly investigated by techniques of XRD, SEM and TEM images, FT-IR, Raman, and XPS spectrum, emphasizing the unique microporous in defective UiO-66 are conducive to the fabrication of AuNCs. The catalytic performance of the prepared materials in aldehyde oxidation reactions is systematically evaluated, demonstrating the remarkable efficiency of dispersed Au@UiO-66-25 with high-content (9.09 wt%) Au-loading and ultra-small size (~2.7 nm). Moreover, mechanistic insights into the catalytic process under mild conditions (70 °C for 1 h) are provided, elucidating the determination of defective UiO-66 in the confined fabrication of AuNCs and subsequent furfural adsorption, which underlie the principles governing the observed enhancements. This study establishes the groundwork for the synthesis of highly dispersed and catalytically active metal nanoparticles using defective MOFs as a platform, advancing the catalytic esterification reaction of furfural to the next level.
Topics: Gold; Metal Nanoparticles; Oxidation-Reduction; Aldehydes; Catalysis; Metal-Organic Frameworks; Porosity; Esterification; Spectroscopy, Fourier Transform Infrared
PubMed: 38928488
DOI: 10.3390/ijms25126779 -
International Journal of Molecular... Jun 2024Coenzyme Q10 (CoQ10) plays a key role in many aspects of cellular metabolism. For CoQ10 to function normally, continual interconversion between its oxidised (ubiquinone)... (Review)
Review
Coenzyme Q10 (CoQ10) plays a key role in many aspects of cellular metabolism. For CoQ10 to function normally, continual interconversion between its oxidised (ubiquinone) and reduced (ubiquinol) forms is required. Given the central importance of this ubiquinone-ubiquinol redox cycle, this article reviews what is currently known about this process and the implications for clinical practice. In mitochondria, ubiquinone is reduced to ubiquinol by Complex I or II, Complex III (the Q cycle) re-oxidises ubiquinol to ubiquinone, and extra-mitochondrial oxidoreductase enzymes participate in the ubiquinone-ubiquinol redox cycle. In clinical terms, the outcome of deficiencies in various components associated with the ubiquinone-ubiquinol redox cycle is reviewed, with a particular focus on the potential clinical benefits of CoQ10 and selenium co-supplementation.
Topics: Ubiquinone; Humans; Oxidation-Reduction; Mitochondria; Animals; Selenium; Ataxia; Muscle Weakness; Mitochondrial Diseases
PubMed: 38928470
DOI: 10.3390/ijms25126765 -
International Journal of Molecular... Jun 2024Water is a major requirement for our bodies, and alkaline water has induced an antioxidant response in a model of natural aging. A series of recent reports have shown...
Water is a major requirement for our bodies, and alkaline water has induced an antioxidant response in a model of natural aging. A series of recent reports have shown that aging is related to reduced water intake. Hydrogen-rich water has been suggested to exert a general antioxidant effect in relation to both improving lifestyle and preventing a series of diseases. Here, we wanted to investigate the effect of the daily intake of hydrogen-rich alkaline water (HAW) in counteracting the redox imbalance induced in a model of HO-treated mice. Mice were treated with HO for two weeks and either left untreated or supplied with HAW. The results show that HAW induced a reduction in the ROS plasmatic levels that was consistent with the increase in the circulating glutathione. At the same time, the reduction in plasmatic 8-hydroxy-2'-deoxyguanosine was associated with reduced DNA damage in the whole body. Further analysis of the spleen and bone marrow cells showed a reduced ROS content consistent with a significantly reduced mitochondrial membrane potential and superoxide accumulation and an increase in spontaneous proliferation. This study provides evidence for a clear preventive and curative effect of HAW in a condition of systemic toxic condition and redox imbalance.
Topics: Animals; Mice; Hydrogen Peroxide; Hydrogen; Oxidation-Reduction; Reactive Oxygen Species; Water; Oxidative Stress; Antioxidants; DNA Damage; Male; Membrane Potential, Mitochondrial; 8-Hydroxy-2'-Deoxyguanosine; Glutathione; Dietary Supplements
PubMed: 38928440
DOI: 10.3390/ijms25126736 -
International Journal of Molecular... Jun 2024The lumen of the endoplasmic reticulum (ER) is usually considered an oxidative environment; however, oxidized thiol-disulfides and reduced pyridine nucleotides occur...
The lumen of the endoplasmic reticulum (ER) is usually considered an oxidative environment; however, oxidized thiol-disulfides and reduced pyridine nucleotides occur there parallelly, indicating that the ER lumen lacks components which connect the two systems. Here, we investigated the luminal presence of the thioredoxin (Trx)/thioredoxin reductase (TrxR) proteins, capable of linking the protein thiol and pyridine nucleotide pools in different compartments. It was shown that specific activity of TrxR in the ER is undetectable, whereas higher activities were measured in the cytoplasm and mitochondria. None of the Trx/TrxR isoforms were expressed in the ER by Western blot analysis. Co-localization studies of various isoforms of Trx and TrxR with ER marker Grp94 by immunofluorescent analysis further confirmed their absence from the lumen. The probability of luminal localization of each isoform was also predicted to be very low by several in silico analysis tools. ER-targeted transient transfection of HeLa cells with Trx1 and TrxR1 significantly decreased cell viability and induced apoptotic cell death. In conclusion, the absence of this electron transfer chain may explain the uncoupling of the redox systems in the ER lumen, allowing parallel presence of a reduced pyridine nucleotide and a probably oxidized protein pool necessary for cellular viability.
Topics: Humans; Thioredoxins; Endoplasmic Reticulum; Oxidation-Reduction; HeLa Cells; Thioredoxin-Disulfide Reductase; Mitochondria; Apoptosis; Cell Survival
PubMed: 38928353
DOI: 10.3390/ijms25126647 -
International Journal of Molecular... Jun 2024Hydrogen sulfide (HS) is a novel gasotransmitter. Sucrose (SUC) is a source of cellular energy and a signaling molecule. Maize is the third most common food crop...
Hydrogen sulfide (HS) is a novel gasotransmitter. Sucrose (SUC) is a source of cellular energy and a signaling molecule. Maize is the third most common food crop worldwide. However, the interaction of HS and SUC in maize thermotolerance is not widely known. In this study, using maize seedlings as materials, the metabolic and functional interactions of HS and SUC in maize thermotolerance were investigated. The data show that under heat stress, the survival rate and tissue viability were increased by exogenous SUC, while the malondialdehyde content and electrolyte leakage were reduced by SUC, indicating SUC could increase maize thermotolerance. Also, SUC-promoted thermotolerance was enhanced by HS, while separately weakened by an inhibitor (propargylglycine) and a scavenger (hypotaurine) of HS and a SUC-transport inhibitor (N-ethylmaleimide), suggesting the interaction of HS and SUC in the development of maize thermotolerance. To establish the underlying mechanism of HS-SUC interaction-promoted thermotolerance, redox parameters in mesocotyls of maize seedlings were measured before and after heat stress. The data indicate that the activity and gene expression of HS-metabolizing enzymes were up-regulated by SUC, whereas HS had no significant effect on the activity and gene expression of SUC-metabolizing enzymes. In addition, the activity and gene expression of catalase, glutathione reductase, ascorbate peroxidase, peroxidase, dehydroascorbate reductase, monodehydroascorbate reductase, and superoxide dismutase were reinforced by HS, SUC, and their combination under non-heat and heat conditions to varying degrees. Similarly, the content of ascorbic acid, flavone, carotenoid, and polyphenol was increased by HS, SUC, and their combination, whereas the production of superoxide radicals and the hydrogen peroxide level were impaired by these treatments to different extents. These results imply that the metabolic and functional interactions of HS and sucrose signaling exist in the formation of maize thermotolerance through redox homeodynamics. This finding lays the theoretical basis for developing climate-resistant maize crops and improving food security.
Topics: Zea mays; Hydrogen Sulfide; Oxidation-Reduction; Thermotolerance; Sucrose; Gene Expression Regulation, Plant; Heat-Shock Response; Seedlings; Plant Proteins
PubMed: 38928304
DOI: 10.3390/ijms25126598 -
International Journal of Molecular... Jun 2024An accumulation of reactive oxygen species (ROS) in cardiomyocytes can induce pro-arrhythmogenic late Na currents by removing the inactivation of voltage-gated Na...
An accumulation of reactive oxygen species (ROS) in cardiomyocytes can induce pro-arrhythmogenic late Na currents by removing the inactivation of voltage-gated Na channels including the tetrodotoxin (TTX)-resistant cardiac α-subunit Nav1.5 as well as TTX-sensitive α-subunits like Nav1.2 and Nav1.3. Here, we explored oxidant-induced late Na currents in mouse cardiomyocytes and human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) as well as in HEK 293 cells expressing Nav1.2, Nav1.3, or Nav1.5. Na currents in mouse cardiomyocytes and hiPSC-CMs treated with the oxidant chloramine T (ChT) developed a moderate reduction in peak current amplitudes accompanied by large late Na currents. While ChT induced a strong reduction in peak current amplitudes but only small persistent currents on Nav1.5, both Nav1.2 and Nav1.3 produced increased peak current amplitudes and large persistent currents following oxidation. TTX (300 nM) blocked ChT-induced late Na currents significantly stronger as compared to peak Na currents in both mouse cardiomyocytes and hiPSC-CMs. Similar differences between Nav1.2, Nav1.3, and Nav1.5 regarding ROS sensitivity were also evident when oxidation was induced with UVA-light (380 nm) or the cysteine-selective oxidant nitroxyl (HNO). To conclude, our data on TTX-sensitive Na channels expressed in cardiomyocytes may be relevant for the generation of late Na currents following oxidative stress.
Topics: Myocytes, Cardiac; Humans; Animals; Tetrodotoxin; Mice; Induced Pluripotent Stem Cells; HEK293 Cells; Oxidation-Reduction; Chloramines; Reactive Oxygen Species; NAV1.5 Voltage-Gated Sodium Channel; Sodium; Action Potentials; Tosyl Compounds
PubMed: 38928302
DOI: 10.3390/ijms25126596