1. Institute
of Traditional Chinese Medicine and Natural Products, College of Pharmacy, Jinan University, Guangzhou 510632, People's Republic of China
2. State
Key Laboratory of Bioorganic and Natural Products Chemistry, Shanghai
Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, People's Republic of China
3. School
of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, People's Republic of China