INTRODUCTION Green, black and pu-erh teas are known to have strong antiradical properties in comparison to other plant raw materials. In this study fifteen different teas belonging to three types, green, black, and pu-erh tea (five of each kind), were investigated for their antiradical properties. Antiradical activity of extracts and raw materials was measured using DPPH and ABTS(•+) radicals. ...

Stable free radical scavenging and antiperoxidative activities of resveratrol, a component of grapes and red wine, were evaluated and compared with some other known bioflavonoids (quercetin, catechin, kaempferol, myricetin, fisetin, ellagic acid and naringenin) widely present in the plant kingdom. Free radical scavenging activity was measured in an in vitro chemical system (DPPH assay), while f...

The plant phenolic compounds such as flavonoids, tannins and phenolic acids appeared to be strong antiradical and antioxidant compounds. The number of hydroxy groups and the presence of a 2,3-double bond and orthodiphenolic structure enhance antiradical and antioxidative activity of flavonoids. The glycosylation, blocking the 3-OH group in C-ring, lack of a hydroxy group or the presence of only...

The group of 21 novel semi-synthetic derivatives of quercetin was screened for the antiradical efficiency in a DPPH assay. The initial fast absorbance decrease of DPPH, corresponding to the transfer of the most labile H atoms, was followed by a much slower absorbance decline representing the residual antiradical activity of the antioxidant degradation products. Initial velocity of DPPH decolori...

Although the term 'antioxidant' is used very frequently, there are problems with the definition of antioxidants and estimation of antioxidant activity. The distinction between antioxidant and antiradical activities is not always obvious. This minireview discusses critically the principles, advantages and limitations of the most frequently used methods of estimation of antiradical and antioxidan...

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...

Present research was to evaluate and compare the antiradical and antioxidant activities of extracts from Spirulina platensis. In the present study, three extracts (Water, absolute methanol and 50% methanol in water) were analyzed for the total phenolic compounds, phycobiliprotein content: Antiradical and antioxidant activities were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-az...

The in vitro antiradical activity of Schisandra chinensis lignans was investigated using DPPH, ABTS+, Fenton reaction inhibition and tyrosine-nitration inhibition assays, as were the in vivo antidiabetic activities of selected lignans in an animal model of alloxan-induced diabetes. Different degrees of antiradical activity were found, depending upon the structural parameters of the tested compo...

Chokeberry and elderberry fruits are rich sources of polyphenols, the compounds with significant antiradical and chelating properties. They are studied intensively because of beneficial effects on human health. In this study, three fractions enriched with different classes of polyphenols were isolated from chokeberry and elderberry to study their antiradical activity by DPPH test. The first fra...

The importance of molecules with antiradical potency that are produced in the human body has significantly increased. Among others, neurotransmitters and their metabolites act as the first line of defense against oxidative stress in the peripheral endocrine and the central nervous systems. Dopamine (DO), epinephrine (EP), norepinephrine (NE), l-DOPA, catechol, and three metabolites of dopamine ...