1. Institute of Traditional Chinese Medicine and Natural Products International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE) College of Pharmacy Jinan University Guangzhou 510632 P. R. China
2. Key Laboratory of Combinatorial Biosynthesis and Drug Discovery Ministry of Education School of Pharmaceutical Sciences Wuhan University Wuhan 430071 P. R. China
3. Department of Pharmacology Case Comprehensive Cancer Center Case Western Reserve University School of Medicine Cleveland OH 44106 USA