Aliquots of 0.5 ml of extract were added to test tube containing 0.1
ml of 10% aluminum nitrate, 0.1 ml 1M aqueous potassium acetate
and 4.3 ml of 80% ethanol. The reaction tubes were set aside for 40 min at room temperature. At the end of this time, optical density of
each sample was determined at 415 nm using a UV
spectrophotometer. Total flavonoids content was calculated by
interpolation on a standard curve established with a reference
standard, quercetin. Quercetin and Folin‐Ciocalteu reagent were
obtained from Sigma‐Aldrich, Germany