1. Jiangsu Key Laboratory of Chiral Pharmaceuticals Biosynthesis Taizhou University Taizhou 225300 P. R. China
2. Center for Novel Drug Development of Taizhou Taizhou 225300 P. R. China
3. State Key Laboratory of Phytochemistry and Plant Resources in West China Kunming Institute of Botany Chinese Academy of Sciences Kunming 650201 P. R. China