1. Department of Chemistry & Biochemistry, University of California, Santa Barbara, California 93106, United States
2. Department of Chemistry, University of Louisville, Louisville, Kentucky 40292, United States
3. PHT International, Inc., Shanghai, 200336 China
4. Novartis Pharma AG, 4056 Basel, Switzerland
5. Novartis Institute of Medical Research, Cambridge, Massachusetts 02129, United States