Quantitative determination of total phenolic content
The total phenolic content of the crude methanol extract was determined by using a modified Folin-
Ciocalteu method with ferulic acid (Sigma Chemical Co.) as a standard [25]. Folin-Ciocalteu reagent
(0.25 mL, Fluka) was added to methanolic extract solution of (1.0 mg mL-1, 10 mL), then 20%
aqueous sodium carbonate solution (1.2 mL) was added and the tube vortexed and then incubated for
40 minutes. A blue color appeared and the absorbance was measured at 725 nm with a Hitachi U-2000
Spectrophotometer. All measurements were made in triplicates and the results expressed as mg of
ferulic acid per gram of sample.
Acknowledgements
This research was supported by RU research grant No. 1001/PKIMIA/811016 and
304/229/PKIMIA/637059.