1. CAS Key Laboratory of Chemistry of Northwestern Plant Resources and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China
2. University of Chinese Academy of Sciences, Beijing 100049, China
3. College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, China
4. Department of Applied Chemistry and Biochemistry, Kumamoto University, Kumamoto 860-8555, Japan