Springer protocols feed by Biochemistry 
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This is an RSS file. You can use it to subscribe to this data in your favourite RSS reader or to display this data on your own website or blog.Measuring Antioxidant and Prooxidant Capacity Using the Crocin Bleaching Assay (CBA)
The Crocin Bleaching Assay (CBA) appears in literature as an in vitro method for measuring antioxidant and prooxidant capacity of model dietary antioxidants, food formulations, pharmaceuticals, and biological samples. The assay is based on simple competitive reactions between a colored probe, crocin, and the test compounds/constituents for scavenging peroxyl radicals generated after thermolysis of a water-soluble azo-initiator. So far, several researchers in the fields of food chemistry, nutrition and clinical biochemistry have sporadically addressed critical views about advantages, limitations and potential field of CBA a...
Source: Springer protocols feed by Biochemistry - October 20, 2014 Category: Biochemistry Source Type: news
Substituted Pyridoindoles as Biological Antioxidants: Drug Design, Chemical Synthesis, and Biological Activity
Great effort has been devoted to design and synthesize biologically active and pharmacologically acceptable antioxidants. Although a number of efficient antioxidant compounds have been designed, synthesized, and tested in animals, none of them have demonstrated sufficient efficacy in human clinical trials without undesirable side effects. Thus new pharmacologically applicable antioxidants have been sought for. Substituted pyridoindoles represent a broad spectrum of pharmacologically active substances including highly effective scavengers of reactive oxygen species. The hexahydropyridoindole scaffold represents a valuable l...
Source: Springer protocols feed by Biochemistry - October 20, 2014 Category: Biochemistry Source Type: news
Preoxiredoxin Family Members (Prx3 and Prx4) and Pregnancy Disorder (Recurrent Pregnancy Loss)
Placenta is a pregnancy unique tissue, and proper formation of placenta is a key phenomenal step for success of a pregnancy. Peroxiredoxins (Prxs) are a family of antioxidant proteins. This family is composed of six members, among which Peroxiredoxin 3 (Prx3) and Peroxiredoxin 4 (Prx4) are expressed by cytotrophoblast cells and play an important role in the implantation and a normal placentation through their antioxidant activities. (Source: Springer protocols feed by Biochemistry)
Source: Springer protocols feed by Biochemistry - October 20, 2014 Category: Biochemistry Source Type: news
Mass Spectrometry Detection of Isolevuglandin Adduction to Specific Protein Residues
The aging process seems to be associated with oxidative stress and hence increased production of lipid peroxidation products, including isolevuglandins (isoLGs). The latter are highly reactive γ-ketoaldehydes which can form covalent adducts with primary amino groups of enzymes and proteins and alter the properties of these biomolecules. Yet little is currently known about amino acid-containing compounds affected by isoLG modification in different age-related pathological processes. To facilitate the detection of these biomolecules, we developed a strategy in which the purified enzyme (or protein) of interest is first...
Source: Springer protocols feed by Biochemistry - October 20, 2014 Category: Biochemistry Source Type: news
Automatic Flow Injection Analysis (FIA) Determination of Total Reducing Capacity in Serum and Urine Samples
Automation of total antioxidant capacity assessment can substantially increase the determination throughput, allowing large scale studies and screening experiments. Total reducing capacity evaluation can be implemented under different chemistries, including the CUPRAC—Cupric Ion Reducing Antioxidant Capacity —assay. This assay is based on reduction of Cu(II)-neocuproine complex to highly colored Cu(I)-neocuproine complex by reducing (antioxidant) components of biological samples. In this chapter, we propose an automatic flow injection method for evaluation of total reducing capacity in serum and urine samples, ...
Source: Springer protocols feed by Biochemistry - October 20, 2014 Category: Biochemistry Source Type: news
Computational Studies on Conformation, Electron Density Distributions, and Antioxidant Properties of Anthocyanidins
Computational studies carried out at density functional theory levels are able to provide reliable chemical information about medium sized compounds as anthocyanins and their aglycons (anthocyanidins). Thus, they indicate that the most stable tautomers in aqueous solution for the main anthocyanidins (excluding pelargonidin) are deprotonated at C4′ in the neutral forms, while deprotonations at C5 and C4′ characterize the most stable anions in solution. QTAIM electron density analysis (overviewed in brief in the methods section) shows that Lewis structures usually employed give rise to unreliable atomic charges. ...
Source: Springer protocols feed by Biochemistry - October 20, 2014 Category: Biochemistry Source Type: news
Antioxidant Activity Evaluation Involving Hemoglobin-Related Free Radical Reactivity
Two methods for the measurement of antioxidant capacity are described: one based on a chronometric variation of a hemoglobin ascorbate peroxidase assay and the other based on electron paramagnetic resonance (EPR) spectra collected upon alkaline treatment of ethanolic samples. The involved chemical mechanisms are discussed, alongside the most important benefits and shortcomings; the assays offer new qualitative and quantitative information on samples of biological as well as synthetic origin. (Source: Springer protocols feed by Biochemistry)
Source: Springer protocols feed by Biochemistry - October 20, 2014 Category: Biochemistry Source Type: news
Fe3+–Fe2+ Transformation Method: An Important Antioxidant Assay
If we look at the multitude of varied and interesting reaction that constitute biochemistry and bioorganic chemistry, it is possible to classify a great many as either oxidation or reduction reactions. The reducing agent transfers electrons to another substance and is thus it oxidized. And, because it gives electrons, it is also called an electron donor. Electron donors can also form charge transfer complexes with electron acceptors. Reductants in biochemistry are very diverse. For example ferric ions (Fe3+) are good reducing agents. Also, different bioanalytical reduction methods are available such as Fe3+-ferrous ions (F...
Source: Springer protocols feed by Biochemistry - October 20, 2014 Category: Biochemistry Source Type: news
Portable Nanoparticle Based Sensors for Antioxidant Analysis
Interest in portable sensing devices has increased throughout the past decade. Portable sensors are convenient for use in remote locations and in places with limited resources for advanced instrumentation. Often such devices utilize advanced technology that allows the final user to simply deposit the sample onto the sensing platform without preparation of multiple reagents. Herein, we describe preparation and characterization of a colorimetric paper-based metal oxide sensing array designed for the field detection of polyphenolic antioxidants. This sensor is a good candidate for use in analysis of the antioxidant character ...
Source: Springer protocols feed by Biochemistry - October 20, 2014 Category: Biochemistry Source Type: news
Simultaneous Determination of Ascorbic Acid, Aminothiols, and Methionine in Biological Matrices Using Ion-Pairing RP-HPLC Coupled with Electrochemical Detector
A novel highly sensitive ion-pairing reversed-phase high performance liquid-chromatography/electrochemical detection method for simultaneous determination of l
-ascorbic acid, aminothiols, and methionine in biological matrices is presented. Reduced forms of the analytes are extracted from sample matrices with 10 % m-phosphoric acid solution(aqueous). To determine the total vitamin C, the total aminothiols, and the total methionine, samples are treated with tris(2-carboxyethyl)phosphine solution in 0.05 % trifluoroacetic acid solution(aqueous) subsequent to deproteination to reduce the oxidized forms of thes...
Source: Springer protocols feed by Biochemistry - October 20, 2014 Category: Biochemistry Source Type: news
Identification of (Antioxidative) Plants in Herbal Pharmaceutical Preparations and Dietary Supplements
The standard procedures for the identification, authentication, and quality control of medicinal plants and herbs are nowadays limited to pure herbal products. No guidelines or procedures, describing the detection or identification of a targeted plant or herb in pharmaceutical preparations or dietary supplements, can be found. In these products the targeted plant is often present together with other components of herbal or synthetic origin. (Source: Springer protocols feed by Biochemistry)
Source: Springer protocols feed by Biochemistry - October 20, 2014 Category: Biochemistry Source Type: news
Prolongation of the Lag Time Preceding Peroxidation of Serum Lipids: A Measure of Antioxidant Capacity
Antioxidants inhibit oxidation processes and by this affect many biological processes. This, in turn, promotes continuing efforts to synthesize new efficient antioxidants and discover compounds of natural origin capable of preventing peroxidation. Although many assays have been developed to evaluate antioxidants, the search for improved protocols is still actual. The presented protocol is based on the effect of antioxidant on the kinetics of peroxidation of lipids in human blood serum. Specifically, we evaluate the capacity of antioxidant by the relative prolongation of lag phase (delay) of copper-induced peroxidation of l...
Source: Springer protocols feed by Biochemistry - October 20, 2014 Category: Biochemistry Source Type: news
Curcuma longa Attenuates Carbon Tetrachloride-Induced Oxidative Stress in T-Lymphocyte Subpopulations
A comparison of crude curcuminoid extract and purified curcumin was made to evaluate the immunoprotective effect of Curcuma longa (turmeric) Zingiberaceae. Carbon tetrachloride (CCl4) induced selective cytolytic effects among immature (PNA+) thymocytes and peripheral helper (CD4+) T lymphocytes in the spleen were paralleled by a significant reduction in CD25, CD71, and Con A receptor expression. Treatment with curcumanoid crude extract, at two different doses, showed a significant restoration of lymphocyte viability and CD25, CD71, and Con A receptor expression in both immature (PNA+) thymocytes and splenic helper (CD4+) T...
Source: Springer protocols feed by Biochemistry - October 20, 2014 Category: Biochemistry Source Type: news
Evaluation of Physical Integrity of Lipid Bilayer Under Oxidative Stress: Application of Fluorescence Microscopy and Digital Image Processing
Membrane damage as a result of oxidative stress is quantified using digital image heterogeneity analysis of single giant unilamellar vesicles (GUVs) composed of soy phosphatidylcholine (PC), which were found to undergo budding when containing chlorophyll a (Chla) as photosensitizer in the lipid bilayer. Based on digital image heterogeneity analysis, a dimensionless scalar parameter “entropy” for the budding process was found to change linearly during an initial budding stage. Photo-induced peroxidation of PC to form linoleoyl hydroperoxides, further leading to domains of higher polarities in GUVs, was suggested...
Source: Springer protocols feed by Biochemistry - October 20, 2014 Category: Biochemistry Source Type: news
Selenium as a Versatile Center in Fluorescence Probe for the Redox Cycle Between HClO Oxidative Stress and H2S Repair
Selenium is a biologically important trace element and acts as an active center of glutathione peroxidase (GPx). GPx is the important antioxidant enzyme to protect organisms from oxidative damage via catalyzing the reaction between ROS and glutathione (GSH). Mimicking the oxidation–reduction cycles of the versatile selenium core in GPx, we can develop fluorescence probes to detect oxidation and reduction events in living systems. The cellular redox balance between hypochloric acid (HClO) and hydrogen sulfide (H2S) has broad implications in human health and diseases, such as Alzheimer’s disease (AD). Therefore, ...
Source: Springer protocols feed by Biochemistry - October 20, 2014 Category: Biochemistry Source Type: news
