ESTIMATING THE ANTIOXIDANT ACTIVITY FOR NATURAL ANTIOXIDANTS (TOCOCHROMANOL) AND SYNTHETIC ONE BY DPPH

摘要

The tocochromanols (vitamin E) possesses powerful neuroprotective, anticancer, and cholesterol-lo wering properties, current developments in vitamin E research clearly indicate that members of the vitamin E family are not redundant with respect to their biological functions. Objective: the aim of this study was to determine the free radical scavenging capacity of different standard antioxidants (tocochromanols & synthetic) in term of hydrogen donating or radical scavenging activity using the stable DPPH method, dependent on (efficient concentration 50%, EC5 0) parameter under same experimental conditio ns. Me thods: (3 ml) of standard antioxidant after proper dilution with methanol has been prepared in six tubes. Then 1ml of DPPH (200 μmol/L) added to achieve a standard serial chain of 2.5, 5, 7.5, 10, 12.5, 15 μmol/L studied antioxidant. The tubes were shaked and kept in dark until the end of the reaction. The remaining percentage of DPPH (%DPPH. rem) for different antioxidants in different concentrations was determined. All measurements of free radical scavenging activity were performed in triplicate and standard deviation was calculated. The relationship between measured sample and decreasing amount of (%DPPH. rem) have been determined.Results: The results, shows; that the reaction time between DPPH and antio xidants was differed according to the antioxidant used and ranged from five to 110 minutes to completio n. and scavenging activity of BHT were the most and similar to that of BHA, and higher than that of α-T and AP, while the scavenging activity for the rest of antioxidants were decrease in the following order: BHT> BHA> α-T> AP> α-T3> β-T> γ-T> β-T3> γ-T3> δ-T> δ-T3. Conclusion: The study can guide to select suitable antioxidant depending on the scavenging activity of free radical