1. a Department of Natural Product Chemistry , School of Pharmaceutical Sciences, Shandong University , Jinan 250012 , China
2. c Laboratory of Pharmacognosy and Phytochemistry , School of Pharmaceutical Sciences, University of Geneva, University of Lausanne , Quai Ernest-Ansermet 30, CH-1211 Geneva 4 , Switzerland
3. b Qilu Hospital, Shandong University , Jinan, 250012 , China