1. State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650204, People's Republic of China, School of Pharmacy, Shanghai Jiao Tong University, Shanghai 200030, People's Republic of China, Yunnan Key Laboratory of Pharmacology for Natural Products, Kunming Medical College, Kunming 650031, People's Republic of China, and Department of Pharmacology, Dali Medical College, Dali 671000, People's Republic of China