1. Department of Cellular Medicine, School of Medicine, University of Dundee, Dundee DD1 9SY, U.K.
2. Department of Chemistry, Sardar Patel University, Vallabh Vidyanagar 388120, Gujarat, India
3. Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, U.S.A.
4. Department of Chemistry, University of California, Riverside, CA 92521, U.S.A.
5. Department of Pharmaceutical Sciences, University of California, Irvine, CA 92697, U.S.A.