1. School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu 273165, Shandong, P. R. China
2. Qinghai Provincial Key Laboratory of Tibetan Medicine Research and CAS Key Laboratory of Tibetan Medicine Research, Northwest Institute of Plateau Biology, Qinghai 81000, P. R. China
3. Green Pharmaceutical Technology Key Laboratory of Luzhou City, School of Pharmacy, Southwest Medical University, Luzhou 646000, Sichuan, P. R. China