1. School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, U.K.
2. School of Chemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, U.K.
3. Medicinal Chemistry & Drug Discovery, Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, U.K.
4. Department of Molecular Haematology; Norwich Medical School, University of East Anglia, Norwich NR4 7TJ, U.K.