The electron donation abilities of

The electron donation abilities of the tested samples were
measured by bleaching of the purple-coloured solution of DPPH

according to the method of Yang, Zhao, Prasad, Jiang, and Jiang
(2010) with minor modifications. About 2 ml different concentrations
of tested samples and BHT prepared in ethanol were added to
4 ml 0.1 mmol/l DPPH ethanol solution. The mixture was shaken
vigorously and left to stand in the dark at room temperature and
the absorbance was measured at 517 nm at different intervals for
30 min. Ethanol was used for the control while distilled water was
used for the blank. The ability to scavenge DPPH
was calculated by
the following equations: