1. Guangdong Province Key Laboratory of Pharmacodynamic Constituents of Traditional Chinese Medicine and New Drugs Research; College of Pharmacy; Jinan University; Guangzhou 510632 P. R. China
2. Department of Medicinal Chemistry; College of Pharmacy; Jinan University; Guangzhou 510632 P. R. China
3. Institute of Pharmaceutical Research; College of Pharmacy; China Pharmaceutical University; Nanjing 210009 P. R. China