1. Key Laboratory of Plant Resources and Chemistry of Arid ZonesXinjiang Technical Institute of Physics and ChemistryChinese Academy of Sciences No. 40-1 South Beijing Road Urumqi 830011 China
2. University of Chinese Academy of Sciences Beijing 100049 China
3. School of Chemical Science and TechnologyYunnan University No. 2 North Cuihu Road Kunming 650091 China