The sample was filtered using filter paper (Sartorius grade 292) and rinsed with 50 mL 100% methanol. The residue was re-extracted with 50 mL of 80% methanol and the solvent was evaporated at 50°C for 24 hrs. Subsequently, sample was dissolved in 50 mL 100% methanol and made up to volume (100 ml) with dionized water.