1. Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, U.K., School of Chemistry, University of St. Andrews, Purdie Building, St. Andrews, Fife KY16 9ST, U.K., and CR-UK Drug-DNA Interactions Research Group, Department of Oncology, Royal Free & University College Medical School, University College London, 91 Riding House Street, London W1W 7BS, U.K.