1. Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, U.K.
2. Department of Chemistry, University of Oxford, Mansfield Road, Oxford, OX1 3TA, U.K.
3. Department of Pharmacy and Biotechnology, Alma Mater Studiorum−Università di Bologna, Via Belmeloro 6, 40126 Bologna, Italy
4. Department of Medical Biotechnologies, University of Siena, 53100 Siena, Italy