1. Department
of Chemistry, Zhejiang University, Hangzhou 310027, P. R. China
2. State
Key Laboratory of Phytochemistry and Plant Resources in West China,
Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, P. R. China
3. Institut
Parisien de Chimie Moleculaire, UMR CNRS 8232, Universite Pierre et Marie Curie-Paris 6, 75005 Paris, France
4. Institute
for Interdisciplinary Research, Jianghan University, Wuhan Economic and Technological
Development Zone, Wuhan 430056, P. R. China