1. Department of Natural Product Chemistry, School of Pharmacy; Second Military Medical University; Shanghai 200433 China
2. State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica; Chinese Academy of Medical Sciences and Peking Union Medical College; Beijing 100050 China
3. Department of Pharmacy, Changhai Hospital; Second Military Medical University; Shanghai 200433 China
4. School of Pharmacy; Shanghai Jiao Tong University; Shanghai 200240 China