1. a Xinjiang Key Laboratory of Plant Resources and Natural Products Chemistry, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , Urumqi, P. R. China
2. b Graduate University of the Chinese Academy of Sciences , Beijing, P. R. China
3. c Beijing Institute of New Technology Application , Beijing, P. R. China
4. d Center for Biochemistry and Biophysics, National Heart, Lung, and Blood Institute, National Institutes of Health , Bethesda, Maryland, USA