Explain how dpph assay is done?
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The DPPH assay is conducted by measuring the antioxidant activity of samples through the reduction of 2,2-diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl (DPPH) radicals to stable DPPH molecules, resulting in a color change from violet to pale yellow . This method is widely used in plant biochemistry to evaluate the scavenging properties of plant constituents against free radicals . The assay involves dropping the antioxidant/sample onto a paper-based circular test zone embedded with DPPH reagent, followed by color intensity measurement using imaging software . Different protocols and conditions, such as reaction times, solvents, and pH, can influence the results of the assay, highlighting the importance of standardization for accurate analysis . Additionally, modifications to the classical DPPH method have shown the antioxidant capacity of sulfur-containing compounds in white wines, comparable to well-known phenolic compounds .
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| The DPPH assay measures antioxidant capacity by determining the quantity of a sample needed to decrease the initial DPPH concentration by 20%, providing insights into the antioxidant potential of white wines. | |
Open access•Journal Article 1 Citations | The DPPH assay is conducted using methods like spectrophotometry, EPR, electrochemistry, and HPLC to evaluate antioxidants' scavenging capacity against the stable free radical DPPH. |
233 Citations | The DPPH assay measures antioxidant capacity by spectrophotometrically assessing DPPH concentration changes due to reaction with antioxidants under various conditions like solvents, pH, and reaction times. |
13 Dec 2019 | The DPPH assay involves mixing plant extracts with DPPH free radical solution, measuring absorbance at 517 nm after 30 minutes to determine antioxidant activity by percentage of inhibition. |
87 Citations | The DPPH assay is conducted by dropping an antioxidant/sample onto a paper-based test zone embedded with DPPH reagent. Reduction of DPPH radicals changes color, indicating antioxidant activity. |
Related Questions
What is DPPH scavenging radical assay?5 answersThe DPPH scavenging radical assay is a method used to evaluate the antioxidant capacity of compounds by measuring their ability to neutralize the stable free radical DPPH (1,1-diphenyl-2-picryl hydrazyl). This assay involves monitoring the decrease in absorbance at 515 nm as DPPH reacts with antioxidants, indicating the kinetics of the reaction as fast, medium, or slow. Different compounds exhibit varying antioxidant activities based on factors like concentration, reaction time, and chemical structure. Various materials, including core carbon nanoparticles and plant extracts, have been tested using the DPPH assay to determine their antioxidative properties. The DPPH assay is a valuable tool in assessing the radical scavenging abilities of compounds and is widely used in antioxidant research.
What is the DPPH method for antioxidants?3 answersThe DPPH method is a spectrophotometric technique used to measure the antioxidant activity of substances. It involves the use of the stable free radical 1,1-diphenyl-2-picryl hydrazyl (DPPH), which has an absorbance maxima at 515 nm. The method measures the disappearance of this absorbance band when DPPH reacts with an antioxidant, indicating the kinetic pathway of the reaction. The reaction kinetics of antioxidants with free radicals are crucial for screening their functionality. The DPPH method is a popular, quick, easy, and affordable approach for measuring antioxidant properties. It can be used to determine the absolute rate constant of the reaction between fast antioxidants and DPPH•, providing information on the activity and capacity of different molecules. The method has been used to evaluate the antioxidant activity of various substances, including young coconut shells and coir, as well as standard antioxidants like reduced glutathione and ascorbic acid. The DPPH method can be adapted for application to biofuels and oil-based automotive fluids, and can provide insights into the structure-activity relationships of phenolic antioxidants.
How does the DPPH test work?3 answersThe DPPH test is a method used to measure the antioxidant activity of substances. It involves the reaction between the stable radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) and an antioxidant. The DPPH radical is deep violet in color, and when it reacts with an antioxidant, it is reduced to a stable DPPH molecule, resulting in a change in color from deep violet to pale yellow. The extent of the color change is inversely proportional to the antioxidant activity of the substance being tested. The DPPH test can be performed using different methods, such as spectrophotometry or HPLC, to measure the absorbance or peak inhibition of the DPPH radical. This test is widely used in various fields, including pharmacology, food chemistry, toxicology, and environmental studies, to evaluate the antioxidant capacity of substances and assess their potential health benefits.
Why use dpph test for free radical scavenging activity?5 answersThe DPPH test is used for measuring free radical scavenging activity because it is a popular, quick, easy, and affordable approach for assessing the potential of substances to serve as hydrogen providers or free-radical scavengers (FRS). The DPPH test involves the use of the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical, which is a stabilized free radical that interacts with an odd electron to yield a strong absorbance at 517 nm. When an antioxidant reacts with DPPH, it forms a lower absorbance compound called DPPHH, indicating its ability to scavenge free radicals. The decolorization or yellow hue observed during the DPPH test indicates the reduction in the number of electrons absorbed, which reflects the lowering capacity of the antioxidant. The DPPH test is widely used in various studies, including those investigating the antioxidant properties of natural products such as Ficus religiosa, fish pastes with black garlic, humic substances, and phytoestrogen-containing food and dietary supplements. Smartphone-based colorimetry has also been explored as an alternative method for DPPH testing.
What are the effects of xanthone on the DPPH assay?5 answersXanthones have been found to have various effects on different assays. In terms of the DPPH assay, which measures antioxidant activity, the effects of xanthones have not been specifically mentioned in the provided abstracts. However, it is known that xanthones have antioxidant properties and can scavenge free radicals, which are measured in the DPPH assay. Xanthones are natural active compounds that have been shown to possess a wide range of biological activities, including antioxidant effects. They have been found to be bioavailable and have demonstrated antioxidant capacity in human volunteers after consumption. Xanthones have also been shown to inhibit genotoxic effects induced by certain substances. While the specific effects of xanthones on the DPPH assay are not mentioned in the abstracts, their antioxidant properties suggest that they may have a positive effect on the assay.
What compounds can be detected using the DPPH assay?4 answersThe DPPH assay can detect various compounds, including reducing species in particulate matter (PM) samples. It can also be used to evaluate the antioxidant properties of compounds such as Quercetin, Epigallocatechin-3-Gallate, Indole-3-Carbinol, and Sulforaphane. Additionally, the DPPH assay can be used to detect electron paramagnetic resonance (EPR) in polycrystalline samples of DPPH, which is the standard g-marker for EPR spectroscopy. The assay is also applicable for measuring the antiradical activity of herbal extracts and natural or synthetic compounds, taking into consideration the spectroscopic properties of each substance in the reaction medium. Furthermore, the DPPH assay can be used to measure the antioxidant capacity of tea compounds, such as gallic acid, theobromine, catechuic acid, epigallocatechin, epigallocatechin gallate, caffeine, epicatechin, epicatechin gallate, and gallocatechin gallate.