1. School
of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, Henan 450001 P. R. China
2. Division
of Pharmaceutical Sciences and Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53705 United States
3. School
of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
4. Department
of Chemistry and Biochemistry, University of California, Los Angeles, California 90095 United States