The scavenging activity of 1, 1‐diphenyl‐2‐picrylhydrazyl radical
(DPPH) free radicals by three extracts and known antioxidant was
performed as described by Farrukh A et al., 2006 with some minor
modifications 4. An aliquot of 200 μl of free phenolic (0.25‐2.5
mg/ml), phenolic esters (0.07‐0.7 mg/ml), phenolic glycosides
(0.015‐0.15 mg/ml), Trolox (0.02‐0.20 mg/ml) and BHT (0.015‐0.15
mg/ml) were mixed with 800 μl of 50 mM Tris‐HCl buffer (pH 7.4),
the mixture was then added to 1 mL of 500 μM DPPH in ethanol.
Methanol (200 μl) only was used as the experimental control. The
reaction mixtures were incubated for 30 min at at room
temperature and the decrease in absorbance was measured at 517
nm. The percent inhibition was calculated from the following
equation and results were expressed as “percentage inhibition” (%)
of the DPPH on of dry weight.