1. Institute of Traditional Chinese Medicine and Natural Products; College of Pharmacy; Jinan University; No. 601 Huangpu Avenue Guangzhou 510632 P. R. China
2. Key Laboratory of Combinatorial Biosynthesis and Drug Discovery; Ministry of Education; School of Pharmaceutical Sciences; Wuhan University; No. 185 Donghu Road Wuhan 430071 P. R. China
3. State Key Laboratory of Bioorganic and Natural Products Chemistry; Shanghai Institute of Organic Chemistry; University of Chinese Academy of Sciences; No.345 Lingling Road Shanghai 200032 P. R. China