Chemical modification of chitosan is increasingly studied for its potential of providing new applications of chitosan. Here, a group of novel chitosan quaternary ammonium derivatives containing pyridine or amino-pyridine were designed and successfully synthesized through chemical modification of chitosan. Pyridine and amino-pyridine were used as functional groups to improve the antifungal activ...

Electron-transfer disproportionation of a 2,2-diphenyl-1-picrylhydrazyl radical (DPPH˙) occurred in the presence of Sc(3+) acting as a strong Lewis acid in deaerated acetonitrile. In contrast, in the case of weaker Lewis acids than Sc(3+), such as Mg(2+) and Li(+), external protons from acetic acid were required for the disproportionation of DPPH˙ to occur.

Eugenol, isoeugenol, caffeic acid, ferulic acid, isoferulic acid, estragole, trans-anethole, and paeonol are components of a Chinese herbal medicine used as a painkiller and stomachic. We investigated the potential role of these compounds as antioxidants. We studied the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical-scavenging effect of these molecules, together with some glycoside derivatives, t...

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...

OBJECTIVES Potato (Solanum tuberosum L.), as a whole food, contains high levels of vitamins and important antioxidants including phenolic acids, carotenoids and flavonoids. The objective of this study was to determine the total phenolic content and antioxidant activities of three common potatoes (Solanum tuberosum) cultivars in Iran i.e., Savalan, Agria and Sante. MATERIALS AND METHODS Phenol...

Applications of antioxidants are increasing due to their multiple roles in minimising harmful effects of oxidative stress. 2,2-diphenyl-1-picrylhydrazyl (DPPH ) radical scavenging assay is routinely practiced for the assessment of antiradical properties of different compounds. A detailed literature survey revealed use of different materials and methods for DPPH assay by different investigators ...

This study was undertaken to examine the antioxidant activity of methanolic extract of seeds of Trigonella foenum-graecum seeds using DPPH free radical scavenging assay. The IC50 (The concentration of sample required to scavenge 50% of DPPH free radical) was calculated by plotting graph between % inhibition vs concentration. The Ascorbic acid was used as standard antioxidant in comparison to me...

KARAMAĆ M., BUCIŃSKI A., PEGG R. B., AMAROWICZ R. (2005): Antioxidant and antiradical activity of ferulates. Czech J. Food Sci., 23: 64–68. Antioxidant and antiradical activities of ferulates (i.e., ferulic acid, isoferulic acid, coniferyl aldehyde, and methyl ferulate) were investigated using a β-carotene-linoleate model system and a DPPH radical scavenging assay, respectively. Compounds so te...