*2.5.1. Preparation of standard solution, test sample and DPPH solution*

Standard solution is prepared by dissolving 10 mg of ascorbic acid in 10 ml of methanol to give the concentration of 1 mg/1 ml. Stock solution is prepared by dissolving 5 mg of methanolic, hexanoic and distilled water extract in to 5 ml of methanol, hexane and distilled water respectively to give the concentration of 1 mg/1 ml. 0.1 mM DPPH is prepared by dissolving 11 mg of DPPH in 8.46 ml of distilled water. It is protected from light by covering the tubes by aluminum foil. **Procedure:** (1) In 3 ml of methanol, 150 μl DPPH is added and reading is taken at 516 nm as control. (2) 0.2, 0.4, 0.6, 0.8, and 1.0 ml aliquots are taken from the test sample. (3) The test sample is diluted by adding methanol up to 3 ml. (4) 150 μl DPPH is added to each of the tubes. (5) Absorbance is taken by UV–visible spectrophotometer at 516 nm. (6) The % of antiradical activity is calculated by using the following equation.

Calculation

Calculation

$$\% \text{ of antiradical activity} = \frac{\text{Control absorbance} - \text{Sample absorbance}}{\text{Control absorbance} \text{!}} \times 100\%$$
