1. Department of Chemistry, Capital Normal University, No. 105, Xisanhuanbeilu, Haidian District, Beijing 100048, PR China
2. College of Pharmacy, Qinghai Nationalities University, No. 3 Bayizhong Road, Xining 810000, PR China
3. Beijing University of Chinese Medicine, No. 11 Beisanhuandonglu, Chaoyang District, Beijing 100029, PR China