Affiliation: | 1. State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, P.?R. China;2. Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, P.?R. China, (phone: +86‐931‐4968208;3. fax: +86‐931‐8277088) |