1. Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, U.K.
2. Department of Chemistry, University of Ghana, P.O. Box LG56, Legon-Accra, Ghana
3. CCMAR and Department of Chemistry
and Pharmacy, University of Algarve, 8005-139 Faro, Portugal
4. Research Centre for Drugs and Diagnostics, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, U.K.
5. School of Pharmacy, Keele University, Keele ST5 5BG, U.K.