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Dissection of NSY50-Induced Defense in Cucumber Roots against f. sp. by Target Metabolite Profiling.Biology Jul 2022To gain insights into the roles of beneficial PGPR in controlling soil-borne disease, we adopted a metabolomics approach to investigate the beneficial impacts of NSY50...
To gain insights into the roles of beneficial PGPR in controlling soil-borne disease, we adopted a metabolomics approach to investigate the beneficial impacts of NSY50 on cucumber seedling roots under the pathogen of f. sp. (FOC). We found that NSY50 pretreatment (NSY50 + FOC) obviously reduced the production of reactive oxygen species (ROS). Untargeted metabolomic analysis revealed that 106 metabolites responded to NSY50 and/or FOC inoculation. Under FOC stress, the contents of root osmotic adjustment substances, such as proline and betaine were significantly increased, and dehydroascorbic acid and oxidized glutathione (GSH) considerably accumulated. Furthermore, the contents of free amino acids such as tryptophan, phenylalanine, and glutamic acid were also significantly accumulated under FOC stress. Similarly, FOC stress adversely affected glycolysis and the tricarboxylic acid cycles and transferred to the pentose phosphate pathway. Conversely, NSY50 + FOC better promoted the accumulation of α-ketoglutaric acid, ribulose-5-phosphate, and 7-phosphosodiheptanone compared to FOC alone. Furthermore, NSY50 + FOC activated GSH metabolism and increased GSH synthesis and metabolism-related enzyme activity and their encoding gene expressions, which may have improved redox homoeostasis, energy flow, and defense ability. Our results provide a novel perspective to understanding the function of NSY50, accelerating the application of this beneficial PGPR in sustainable agricultural practices.
PubMed: 36101409
DOI: 10.3390/biology11071028 -
Molecules (Basel, Switzerland) Oct 2021The analysis of total vitamin C content in food is most frequently performed by reducing dehydroascorbic acid to ascorbic acid, which is then assayed with the technique...
The analysis of total vitamin C content in food is most frequently performed by reducing dehydroascorbic acid to ascorbic acid, which is then assayed with the technique of high-performance liquid chromatography combined with spectrophotometric detection. Tris(2-carboxyethyl)phosphine is currently the only agent in use that efficiently reduces dehydroascorbic acid at pH < 2. Therefore, there is a continued need to search for new reducing agents that will display a high reactivity and stability in acidic solutions. The objective of the study was to verify the applicability of unithiol and tris(hydroxypropyl)phosphine for a reducing dehydroascorbic acid in an extraction medium with pH < 2. The conducted validation of the newly developed method of determining the total content of vitamin C using tris(hydroxypropyl)phosphine indicates its applicability for food analysis. The method allows obtaining equivalent results compared to the method based on the use of tris(2-carboxyethyl)phosphine. The low efficiency of dehydroascorbic acid reduction with the use of unithiol does not allow its application as a new reducing agent in vitamin C analysis.
Topics: Ascorbic Acid; Chromatography, High Pressure Liquid; Dehydroascorbic Acid; Food; Food Analysis; Indicators and Reagents; Phosphines; Reducing Agents
PubMed: 34684843
DOI: 10.3390/molecules26206263 -
Frontiers in Chemistry 2022L-Ascorbic acid (ASC), commonly known as vitamin C, acts as an anti-oxidant in the biological system. It is extensively used as an excipient in pharmaceutical industry,...
L-Ascorbic acid (ASC), commonly known as vitamin C, acts as an anti-oxidant in the biological system. It is extensively used as an excipient in pharmaceutical industry, food supplements in fruit juices, and food materials due to its free radicals scavenging activity. Main drawback of ASC is its poor aqueous stability owing to the presence of lactone moiety that is easily oxidized to dehydroascorbic acid and further degraded. To improve aqueous stability and inhibit oxidative degradation, ASC was co-crystallized to constitute binary eutectic compositions with mono and di-saccharides such as glucose, sucrose, lactose, and mannitol. The eutectics were confirmed by their (single) lower melting endotherm compared to ASC and sugars, although Powder X-ray diffraction (PXRD) and Fourier transform Infrared spectroscopy (FT-IR) data confirmed the characteristics of their physical mixture. Scanning electron microscope (SEM) images of the binary eutectics confirmed their irregular morphology. The ASC eutectics exhibited improved shelf-life by 2-5-fold in weakly acidic (pH 5) and neutral (pH 7) aqueous buffer medium, whereas the eutectic with glucose enhanced shelf-life only by 1.1-1.2-fold in acidic medium (pH 3.3 and 4). Notably, stabilizing effect of the sugar eutectics decreased with increasing acidity of the medium. In addition, higher binding energy of the disaccharide eutectics partially supports the aqueous stability order of ASC in the neutral pH medium due to more number of non-bonded interactions than that of monosaccharides.
PubMed: 35615307
DOI: 10.3389/fchem.2022.754269 -
The Biochemical Journal May 1996Dehydroascorbic acid-reducing activity in normal human neutrophil lysates was characterized and identified by activity-based purification and measurement of newly...
Dehydroascorbic acid-reducing activity in normal human neutrophil lysates was characterized and identified by activity-based purification and measurement of newly synthesized ascorbate by HPLC. The initial reducing activity was non-dialysable and could not be accounted for by the activity of glutathione as a reducing agent. The reducing activity was purified to homogeneity as an 11 kDa protein. The protein had a specific activity of 3 mumol/min per mg of protein and was glutathione dependent. Kinetic experiments showed that the protein had a K(m) for glutathione of 2.0 mM and a K(m) for dehydroascorbic acid of 250 microM. Dehydroascorbic acid reduction by the purified protein was pH dependent and was maximal at pH 7.5. Peptide fragments from the purified protein were analysed for amino acid sequence and the protein was identified as glutaredoxin. By using degenerate oligonucleotides based on the amino acid sequence, glutaredoxin was cloned from a human neutrophil library. Expressed purified glutaredoxin displayed reducing activity and kinetics that were indistinguishable from those of native purified enzyme. Several approaches indicated that glutaredoxin was responsible for the most of the protein-mediated dehydroascorbic acid reduction in lysates. From protein purification data, glutaredoxin was responsible for at least 47% of the initial reducing activity. Dehydroascorbic acid reduction was at least 5-fold greater in neutrophil lysates than in myeloid tumour cell lysates, and glutaredoxin was detected in normal neutrophil lysates but not in myeloid tumour cell lysates by Western blotting. Glutaredoxin inhibitors inhibited dehydroascorbic acid reduction in neutrophil lysates as much as 80%. These findings indicate that glutaredoxin plays a major role in dehydroascorbic acid reduction in normal human neutrophil lysates, and represent the first identification of dehydroascorbic acid reductase in human tissue by activity-based purification.
Topics: Amino Acid Sequence; Base Sequence; Cloning, Molecular; DNA Primers; DNA, Complementary; Dehydroascorbic Acid; Escherichia coli; Gene Expression; Glutaredoxins; Humans; In Vitro Techniques; Kinetics; Models, Biological; Molecular Sequence Data; Molecular Weight; Neutrophils; Oxidation-Reduction; Oxidoreductases; Proteins; Sequence Homology, Amino Acid
PubMed: 8645179
DOI: 10.1042/bj3150931 -
Redox Biology Apr 2016Vitamin C deficiency globally affects several hundred million people and has been associated with increased morbidity and mortality in numerous studies. In this study,... (Comparative Study)
Comparative Study
Vitamin C deficiency globally affects several hundred million people and has been associated with increased morbidity and mortality in numerous studies. In this study, bioavailability of the oxidized form of vitamin C (l-dehydroascorbic acid or DHA)-commonly found in vitamin C containing food products prone to oxidation-was studied. Our aim was to compare tissue accumulation of vitamin C in guinea pigs receiving different oral doses of either ascorbate or DHA. In all tissues tested (plasma, liver, spleen, lung, adrenal glands, kidney, muscle, heart, and brain), only sporadic differences in vitamin C accumulation from ascorbate or DHA were observed except for the lowest dose of DHA (0.25mg/ml in the drinking water), where approximately half of the tissues had slightly yet significantly less vitamin C accumulation than from the ascorbate source. As these results contradicted data from rats, we continued to explore the ability to recycle DHA in blood, liver and intestine in guinea pigs, rats and mice. These investigations revealed that guinea pigs have similar recycling capacity in red blood cells as observed in humans, while rats and mice do not have near the same ability to reduce DHA in erythrocytes. In liver and intestinal homogenates, guinea pigs also showed a significantly higher ability to recycle DHA compared to rats and mice. These data demonstrate that DHA in guinea pigs-as in humans-is almost as effective as ascorbate as vitamin C source when it comes to taking up and storing vitamin C and further suggest that the guinea pig is superior to other rodents in modeling human vitamin C homeostasis.
Topics: Animals; Ascorbic Acid; Ascorbic Acid Deficiency; Dehydroascorbic Acid; Dietary Supplements; Dose-Response Relationship, Drug; Erythrocytes; Guinea Pigs; Humans; Intestines; Liver; Mice; Rats; Tissue Distribution; Vitamins
PubMed: 26609560
DOI: 10.1016/j.redox.2015.11.003 -
Food Chemistry Nov 2016A simple, rapid and reliable method was developed for quantifying ascorbic (AA) and dehydroascorbic (DHAA) acids and validated in 20mM malate buffer (pH 3.8). It...
A simple, rapid and reliable method was developed for quantifying ascorbic (AA) and dehydroascorbic (DHAA) acids and validated in 20mM malate buffer (pH 3.8). It consists in a spectrophotometric measurement of AA, either directly on the solution added with metaphosphoric acid or after reduction of DHAA into AA by dithiothreitol. This method was developed with real time measurement of reactions kinetics in bulk reactors in mind, and was checked in terms of linearity, limits of detection and quantification, fidelity and accuracy. The linearity was found satisfactory on the range of 0-6.95mM with limits of detection and quantification of 0.236mM and 0.467mM, respectively. The method was found acceptable in terms of fidelity and accuracy with a coefficient of variation for repeatability and reproducibility below 6% for AA and below 15% for DHAA, and with a recovery range of 97-102% for AA and 88-112% for DHAA.
Topics: Ascorbic Acid; Dehydroascorbic Acid; Kinetics; Reproducibility of Results; Spectrophotometry, Ultraviolet; Time Factors
PubMed: 27283671
DOI: 10.1016/j.foodchem.2016.05.107 -
Nanomaterials (Basel, Switzerland) Mar 2020The thermal dissipation issue of electronics devices becomes increasingly prominent as they evolve to smaller sizes and more complicated structures. Therefore, the...
The thermal dissipation issue of electronics devices becomes increasingly prominent as they evolve to smaller sizes and more complicated structures. Therefore, the development of materials with excellent heat conduction properties and light weight turns out to be an urgent demand to solve the heat transfer problem of electronics devices with high performance. For this purpose, we put forward an innovative strategy that carbonized dehydroascorbic acid (CDA) be applied to graphene layers for the targeted repair of defects among them and bridge connection of the layers to produce graphene heat conduction materials with excellent properties. Firstly, hydrogen bonds formed from dehydroascorbic acid (DHAA, products of the oxidation of vitamin C) and each of ketone, carboxyl, and oxhydryl groups on graphene layers were absorbed at targeted locations where oxidation graphene produces defects, then targeted repair was conducted for those defects to be filled and for the graphene layers of a small size to grow into large sheet materials with improved continuity by CDA generated in thermally pressing reduction reaction at 800 °C. In our investigation, the planar thermal conductivity of rGO/VC membrane reached 1031.9 ± 10.2 WmK, while the added mass content of vitamin C (VC) was 15%. Being a reference, the planar thermal conductivity of primitive graphene membrane was only 610.7 ± 11.7 WmK.
PubMed: 32187988
DOI: 10.3390/nano10030531 -
The Journal of Biological Chemistry Jul 1997Dehydroascorbic acid (DHA) is rapidly taken up by cells and reduced to ascorbic acid (AA). Using the Xenopus laevis oocyte expression system we examined transport of DHA...
Dehydroascorbic acid (DHA) is rapidly taken up by cells and reduced to ascorbic acid (AA). Using the Xenopus laevis oocyte expression system we examined transport of DHA and AA via glucose transporter isoforms GLUT1-5 and SGLT1. The apparent Km of DHA transport via GLUT1 and GLUT3 was 1.1 +/- 0.2 and 1.7 +/- 0.3 mM, respectively. High performance liquid chromatography analysis confirmed 100% reduction of DHA to AA within oocytes. GLUT4 transport of DHA was only 2-4-fold above control and transport kinetics could not be calculated. GLUT2, GLUT5, and SGLT1 did not transport DHA and none of the isoforms transported AA. Radiolabeled sugar transport confirmed transporter function and identity of all cDNA clones was confirmed by restriction fragment mapping. GLUT1 and GLUT3 cDNA were further verified by polymerase chain reaction. DHA transport activity in both GLUT1 and GLUT3 was inhibited by 2-deoxyglucose, D-glucose, and 3-O-methylglucose among other hexoses while fructose and L-glucose showed no inhibition. Inhibition by the endofacial inhibitor, cytochalasin B, was non-competitive and inhibition by the exofacial inhibitor, 4,6-O-ethylidene-alpha-glucose, was competitive. Expressed mutant constructs of GLUT1 and GLUT3 did not transport DHA. DHA and 2-deoxyglucose uptake by Chinese hamster ovary cells overexpressing either GLUT1 or GLUT3 was increased 2-8-fold over control cells. These studies suggest GLUT1 and GLUT3 isoforms are the specific glucose transporter isoforms which mediate DHA transport and subsequent accumulation of AA.
Topics: Animals; Biological Transport; CHO Cells; Cricetinae; Dehydroascorbic Acid; Deoxyglucose; Glucose Transporter Type 1; Glucose Transporter Type 2; Glucose Transporter Type 3; Glucose Transporter Type 4; Glucose Transporter Type 5; Humans; Kinetics; Membrane Glycoproteins; Monosaccharide Transport Proteins; Muscle Proteins; Mutagenesis, Site-Directed; Nerve Tissue Proteins; Oocytes; Rats; Restriction Mapping; Sodium-Glucose Transporter 1; Xenopus laevis
PubMed: 9228080
DOI: 10.1074/jbc.272.30.18982 -
Free Radical Biology & Medicine Mar 2009Ascorbate (vitamin C) is a vital antioxidant molecule in the brain. However, it also has a number of other important functions, participating as a cofactor in several... (Review)
Review
Ascorbate (vitamin C) is a vital antioxidant molecule in the brain. However, it also has a number of other important functions, participating as a cofactor in several enzyme reactions, including catecholamine synthesis, collagen production, and regulation of HIF-1 alpha. Ascorbate is transported into the brain and neurons via the sodium-dependent vitamin C transporter 2 (SVCT2), which causes accumulation of ascorbate within cells against a concentration gradient. Dehydroascorbic acid, the oxidized form of ascorbate, is transported via glucose transporters of the GLUT family. Once in cells, it is rapidly reduced to ascorbate. The highest concentrations of ascorbate in the body are found in the brain and in neuroendocrine tissues such as adrenal, although the brain is the most difficult organ to deplete of ascorbate. Combined with regional asymmetry in ascorbate distribution within different brain areas, these facts suggest an important role for ascorbate in the brain. Ascorbate is proposed as a neuromodulator of glutamatergic, dopaminergic, cholinergic, and GABAergic transmission and related behaviors. Neurodegenerative diseases typically involve high levels of oxidative stress and thus ascorbate has been posited to have potential therapeutic roles against ischemic stroke, Alzheimer's disease, Parkinson's disease, and Huntington's disease.
Topics: Animals; Antioxidants; Ascorbic Acid; Biological Transport; Brain; Humans; Ischemia; Neurodegenerative Diseases; Neurons; Organic Anion Transporters, Sodium-Dependent; Oxidative Stress; Sodium-Coupled Vitamin C Transporters; Symporters; Synaptic Transmission
PubMed: 19162177
DOI: 10.1016/j.freeradbiomed.2008.12.018 -
ACS Omega Jan 2022Rosmarinic acid-capped silver nanoparticles (Ro-AgNPs) were prepared and applied as a probe for selective colorimetric detection of cyanide (CN) and chromium(VI)...
Rosmarinic acid-capped silver nanoparticles (Ro-AgNPs) were prepared and applied as a probe for selective colorimetric detection of cyanide (CN) and chromium(VI) [Cr(VI)] under different conditions in aqueous media. The carbon atom of CN interacts with the AgNPs, and the carbon atom donates electrons from the HOMO to the vacant orbitals of the coordinatively unsaturated surface atom (Ag). After donating electrons, CN attached onto the surface of the nanoparticles becomes very reactive and interacts with dissolved oxygen and generates reactive oxygen species (ROS) such as superoxide (O ), singlet oxygen (O), and so forth. In this process, Ag oxidizes to Ag and combines with CN forming water-insoluble AgCN, and the ROS (O ) formed reacts with Ag/Ag to form AgO. The oxidation of Ag to Ag resulted in dissolution of AgNPs, which causes disappearance of the surface plasmon resonance band and color change from yellow to colorless. For detection of Cr(VI), ascorbic acid and CN were added first; the ascorbic acid replaced the rosmarinic acid and then reduced the added Cr(VI) to Cr(III), and, in this process, ascorbic acid was oxidized to dehydroascorbic acid, which moved away from the nanoparticles' surface. CN then interacted with the surface Ag atom, got activated, and interacted with dissolved oxygen forming Ag and ROS, which then followed the same process as described for CN to form AgCN and AgO with a color change. The limits of detection were found to be 0.01 and 0.03 μM for CN and Cr(VI), respectively. The material was also used for sensing CN and Cr(VI) in real samples, and the results obtained were satisfactory. For field application, agarose-based strips were prepared by immobilizing the nanoparticles onto the agarose film and successfully used for the detection of CN and Cr(VI) in water.
PubMed: 35036793
DOI: 10.1021/acsomega.1c05946