1. Institute for Molecular Design and Synthesis, School of Pharmaceutical Science and Technology, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, P. R. China
2. Department of Chemistry, Texas A&M University, 3255 TAMU, College Station, Texas 77843, United States
3. International TCM Immunopharmacology Research Center, Henan University of Chinese Medicine, Zhengzhou 450046, Henan Province, P. R. China
4. Department of Chemistry, Texas A&M University at Qatar, P.O. Box 23874, Doha, Qatar