1. School of Chemical and Biological Engineering Georgia Institute of Technology Atlanta GA 30332 USA
2. Department of Chemistry and Biochemistry Jackson State University Jackson MS 39217 USA
3. Drug Design & Discovery Center, State Key Laboratory of Drug Research Shanghai Institute of Materia Medica, Chinese Academy of Sciences Shanghai 201203 China
4. Department of Chemistry Georgia State University Atlanta GA 30302 USA
5. School of Chemistry and Biochemistry Georgia Institute of Technology Atlanta GA 30332 USA
6. Department of Chemistry The Scripps Research Institute La Jolla CA 92037 USA