1. Laboratory of Phytochemistry, Kunming Institute of Botany, Academia Sinica, Kunming 650204, Yunnan, People's Republic of China, School of Pharmacy, Yunnan University, Kunming 650091, Yunnan, People's Republic of China, and Yunnan Laboratory of Pharmacology of Natural Products, Kunming Medical College, Kunming 650031, Yunnan, People's Republic of China