In this study, the antioxidant properties of 80 % ethanol extracts of 16 species of plants from Jeju Island in Korea were evaluated using various antioxidant assays, including the DPPH (1,1-Diphenyl-2-pricrylhydrazyl) radical scavenging, superoxide scavenging, xanthine oxidase inhibition and hydrogen peroxide scavenging activities. Among the 16 plant extracts tested, CN-13 showed strong antioxi...

Moutan cortex, a widely used traditional Chinese medicine for the treatment of various diseases, is the root bark of Peaonia suffruticosa Andrews (Paeoniaceae). In this study, the crude polysaccharides (CPS), paeonol and the crude total glycosides (CTG) of moutan cortex were extracted by the multiple-stage extraction. CPS was extracted by water, paeonol was distilled by steam distillation metho...

Antioxidant potential of leaves of three different species of Annona was studied by using different in vitro models eg., 1,1-diphenyl-2-picryl hydrazyl (DPPH), 2,2-azinobis-(3-ethylbenzothizoline-6-sulphonate) (ABTS), nitric oxide, superoxide, hydroxy radical and lipid peroxidation. The ethanolic extract of A. muricata at 500 microg/ml showed maximum scavenging activity (90.05%) of ABTS radical...

The in vitro antioxidant activities of eight 3-carboxycoumarin derivatives were assayed by the quantitative 1,1-diphenyl-2-picrylhydrazil (DPPH•) radical scavenging activity method. 3-Acetyl-6-hydroxy-2H-1-benzopyran-2-one (C1) and ethyl 6-hydroxy-2-oxo-2H-1-benzopyran-3-carboxylate (C2) presented the best radical-scavenging activity. A quantitative structure-activity relationship (QSAR) study ...

The objective of this study was to evaluate total phenolic content and antioxidant activity of leaf and different parts of fruit (hull, shell, and kernel) of Bene in Ilam province. Total phenolic content was determined with the Folin- Ciocalteu Reagent (FCR); antioxidant activity of methanolic extracts were examined by DPPH (2,2diphenyl- 1- picrylhydrazyl), FRAP (ferric reducing antioxidant pow...

This work proposes the application of batch-injection analysis with amperometric detection to determine the antioxidant capacity of real samples based on the measurement of DPPH radical consumption. The efficient concentration or EC50 value corresponds to the concentration of sample or standard required to scavenge 50% DPPH radicals. For the accurate determination of EC50, samples were incubate...

Various methods employed in evaluating antioxidant activities of various samples gives varying results depending on the specificity of the free radical or oxidant used as a reactant. This study investigated the antioxidant /radical scavenging properties of the methanolic extract of Vernonia amygdalina (MEVA) leaves and studied the relationship between the assay methods. Antioxidant capacity of ...

Stoichiometric evaluation of the radical scavenging activity of O-substituted derivatives at the C-2 position of ascorbic acid (AA) was conducted. Their reaction with a stable radical, 1,1-diphenyl-2-picrylhydrazyl (DPPH), under an acidic condition was assessed by the colorimetric method. 2-O-alpha-D-Glucopyranosyl-L-ascorbic acid (AA-2G) and a series of 6-O-acyl-2-O-alpha-D-glucopyranosyl-L-as...

Present study was designed to compare antioxidant and DNA damage protection of Soxhlet assisted (80% methanol) extract (SEMC) with microwave assisted (80% methanol) extract of Michelia champaca Linn. (MEMC). The in vitro antioxidant activity of SEMC and MEMC were tested for DPPH, hydroxyl radical (OH) by deoxyribose, lipid peroxidation and reducing power capacity. The extracts were also tested ...