Sample powder (500 mg) was extracted with 50 mL of 80 mL/100 mL aqueous ethanol.
This suspensionwas shaken for 45 min at room temperature and filtered through Whatman No. 4 filter paper. The residue was re-extracted five times with additional 25-mL
portions of 80 mL/100 mL ethanol. The combined filtrate was then rotary evaporated at 40 C and redissolved in deionised water to a final volume of 10 mL. The aqueous extract was filtered using a 0.45-mm polyvinylidene fluoride membrane filter and analysed using high-performance liquid chromatography (HPLC).