1. State Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources, Guangxi Normal University, 15 Yucai Road, Guilin, Guangxi, 541004, China. Fax: +86-773-584-8836; Tel: +86-773-584-8836
2. College of Chemistry & Chemical Engineering, Jinggangshan University, Jian, Jiangxi, China