The present work is carried out to study the antioxidant potential of ethanolic extract of Alstonia scholaris Linn. ( Apocynaceae ) using various in vitro tests including 1,1-diphenyl-2-picryl-hydrazil (DPPH . ) free radical scavenging, metal ion chelating, hydrogen peroxide scavenging, superoxide anion radical scavenging, and ferric thiocyanate reducing ability.   Ethanolic ex...

This study investigated the antioxidant activity of functional beverage concentrates containing herbal medicine extracts (FBCH) using various antioxidant assays, such as 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging activity, and reducing power assay. The total polyphenolic content of FBCH (81.45...

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...

objective: the present study was an attempt to study total phenolic content and antioxidant property of the crude ethanolic extract of the roots of azadirachta indica (a. indica). materials and methods: to evaluate the antioxidant properties of the crude extract, some complementary test systems, namely dpph free radical scavenging assay, reducing power assay, and ferrous ion chelating ability a...

The rhizome of Dryopteris crassirhizoma NAKAI exhibited significant antioxidant activity, as assessed by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity in vitro. Two phloroglucinol derivatives, flavaspidic acids PB (1) and AB (2), were isolated from the rhizome of D. crassirhizoma by a bioassay-guided fractionation. 1H-, 13C-NMR, and UV analysis were used to determine the ...

The aim of this study was to evaluate the quality characteristics of seven yacon (Smallanthus sonchifolius Poepp. and Endl.) cultivars (Cajamarca, Cusco, Early White, Late Red, Morado, New Zealand and Quinault) cultivated in the southwest of Germany. The following phyto/chemical traits were investigated in different yacon tuber parts (flesh, peel, and whole tubers): total dry matter, sugar cont...

The methanol extract of the dried ripe fruits of Alpinia rafflesiana was investigated for its DPPH free radical scavenger constituents. 2',3',4',6'-Tetrahydroxychalcone (7), which has never been isolated from natural sources was found to be most active as a DPPH free radical scavenger with the IC50 value of 55 microM. Other known compounds isolated from this species include 5,6-dehydrokawain (1...

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 (...

The health benefits of green and black tea are mainly associated with their antioxidant potential and phenolic compounds. The present study aimed to evaluate the effects of dried rose petals (Rosa damascena) on the antioxidant capacity of green and black tea. Antioxidant capacities of tea and rose infusions were assessed using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and 2, 2-azinobis-3-<...

Mg(2+) enhanced the scavenging activity of (+)-catechin and quercetin against the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH˙), while Al(3+) decreased their activity. Such effects of Mg(2+) and Al(3+) were not observed for kaempferol. Na(+) and Ca(2+) with large ionic radii showed little effect on the DPPH˙-scavenging activity of these three flavonoids.