1. School of Chemistry and Chemical Engineering, Chongqing University , Chongqing, P. R. China
2. Basic Medical College, Chongqing Medical University , Chongqing, China
3. School of Pharmaceutical Sciences, Chongqing University , Chongqing, China
4. Tang Center of Herbal Medicine and Department of Anesthesia & Critical Care, University of Chicago , Chicago, IL, USA