Water (at room temperature) and organic solvents namely methanol, ethanol and acetone (analytically pure) were used as the extraction solvents for comparative experiments. Four gram of ground PSR (40 mash) were extracted with 160ml of the above mentioned solvents, and the conventional methods of leaching extraction (for 2h), ultrasound-assisted extraction (for 30min) and Soxhlet extraction (for 8h) were used, respectively. The extracts were centrifuged at 3600 rpm for 10min, and the supernatants were evaporated to dry and re-dissolved in methanol, kept at −18 ◦C for analysis.