At present, it is widely-known that free radicals are the causes of illness such as cancers, coronary heart disease, Alzheimer’s disease and aging. One method of protection from free radical is the consumption of antioxidant-containing foods or herbs. Several analytical methods have been used for qualitative and quantitative determination of antioxidants. This project aimed to evaluate antioxid...

Free radicals are atoms or molecules with unpaired electrons. Many diseases are caused by free radicals. Normally, free radical formation is controlled naturally by various beneficial compounds known as antioxidants. Several analytical methods have been used for qualitative and quantitative determination of antioxidants, and each has its own specificity. This project aimed to evaluate antioxida...

New potent antioxidants conjugating the catechol (=pyrocatechol; pyrCat) group to two N-termini of modified double-stranded tyrosine residues were synthesized and showed radical scavenging activity with 2,2-diphenyl-1-picrylhydrazyl radical (DPPH radical, DPPH˙) as a free radical model, second-order rate constants for the DPPH˙ scavenging reaction, and the results from electron spin resonance (...

Radical scavenging and antioxidant activities of nine flavonoids previously isolated from the aerial parts of Chenopodium bonus-henricus L. were established using DPPH and ABTS free radicals as well as inhibition of lipid peroxidation in a linoleic acid system by the ferric thiocyanate method. Patuletin glycosides, compounds 1, 2 and 7 showed the highest DPPH (85.78%, 85.59%, 86.07%) and ABTS a...

Fucoxanthin (Fuco) is a characteristic carotenoid of brown seaweeds. In the present study, Fuco and its stereoisomers 9'Z-Fuco, 13Z- and 13'Z-Fuco were extracted from Laminaria japonica Aresch. They were isolated and purified by silica gel column chromatography, Sephadex LH-20, and reversed-phase HPLC. The radical-scavenging activities of the three stereoisomers were evaluated toward 1,1-diphen...

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 FolinCiocalteu Reagent (FCR); antioxidant activity of methanolic extracts were examined by DPPH (2,2diphenyl1picrylhydrazyl), FRAP (ferric reducing antioxidant power) an...

In this study, n-butanol fraction (KBF) and aqueous fraction (KAF) isolated from methanol extract of Koelreuteria paniculata Laxm. leaves were evaluated for their antioxidant potential using (ABTS) 2, 2-Azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid), DPPH (2,2-diphenyl-2-picrylhydrazyl) assay, Reducing power assay and Superoxide anion radical scavenging assay. These fractions were also studi...

− A method for simultaneously identifying antioxidative compounds was developed using time-based LC-MS coupled with DPPH assay regardless of the time consuming process. The methanolic extract of Polygonum aviculare (Polygonaceae) showed significant DPPH radical scavenging activity. Time-based DPPH assay for simultaneous identification of active compounds from the extracts of P. aviculare was us...

the plants of the genus salvia synthesize several types of secondary metabolites with antimicrobial, cytotoxic, and radical scavenging activities and are used in the folk medicine of different countries. eleven salvia species including s. aegyptiaca, s. aethiopis, s. atropatana, s. eremophila, s. hypoleuca, s. limbata, s. nemorosa, s. santolinifolia, s. sclarea, s. syriaca, and s. xanthocheila ...