1. College of Pharmaceutical Sciences, Medical Research Institute, Southwest University, Chongqing 400715, PR China
2. Department of Chemistry, University of South Florida, Tampa, Florida 33620, United States
3. Chongqing Medical University Stomatology College, Chongqing Key Laboratory for Oral Diseases and Biomedical Sciences, Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing 401147, PR China