1. Department of Chemistry, Pfizer, Sandwich CT13 9NJ, U.K.
2. Institute of Biomolecular and Biomedical Sciences, School of Biological Sciences, University of Portsmouth, King Henry I Street, Portsmouth PO1 2DY, U.K.
3. CPC Scientific Incorporated, 1430 Koll Circle Suite 101, San Jose, California 95112, United States