On‐line HPLC method for screening of antioxidants against superoxide anion radical from complex mixtures

Abstract

A practical approach for rapidly screening antioxidants against superoxide anion radicals from complex mixtures was developed based on the quantitative difference in active compounds before and after their reaction. To test the effectiveness of the approach, seven flavonoids with antioxidative properties were investigated both individually and in a mixture. Using the approach, antioxidants could be rapidly separated and screened with a ranked order of activities in the meantime. The radical scavenging activities were in the following order: quercetin > kaempferol > fisetin > puerarin > luteolin > rutin > baicalein. The order of activity was conducted by comparing the scavenging ratio of the antioxidant, which was completely consistent with the results obtained from the traditional electronic spin resonance. Then, the method was successfully applied to black tea extracts. This approach is fast and convenient for screening, isolating, and analyzing potential antioxidants from a mixture with good quantitative and reproducible ability.

Quantification of Mangiferin by High Pressure Liquid Chromatography; Physicochemical and Sensory Evaluation of Functional Mangiferin Drink

“…Ferric reducing antioxidant power (FRAP) of resultant extracts was estimated through the procedure of Sun et al . (). The peel extract (0.5 mL) was mixed with phosphate buffer (1.25 mL, 0.2 M, pH 6.6) and potassium ferricyanide (1.25 mL, 1%).…”

Flavonoids in prevention of diseases with respect to modulation of Ca-pump function

“…Multiple hydroxyl groups, especially in the B-ring, significantly increased the production of hydroxyl radicals in the Fenton reaction, while on the other hand, mono- and dihydroflavonoids failed to exert any prooxidant activity (Heim et al , 2002; Hanasaki et al , 1994). There is also evidence that the 2,3-double bond and 4-oxo arrangement of flavones may promote the formation of ROS induced by divalent copper in the presence of oxygen (Sun et al , 2010). Flavonoid prooxidant properties seem to be concentration dependent.…”

Lipid peroxidation diminishing perspective of isolated theaflavins and thearubigins from black tea in arginine induced renal malfunctional rats

“…The FRAP test was performed according to the guidelines of [ 16 ]. 0.5 mL of respective extract was added in phosphate buffer (1.25 mL, 0.2 M, pH 6.6) and potassium ferricyanide (1.25 mL, 1%).…”