1. Medicinal Chemistry and Natural Products Research Group, School of Pharmacy and Biomolecular Sciences; Liverpool John Moores University; James Parsons Building, Byrom Street Liverpool L3 3AF UK
2. Department of Chemistry; University of Douala, Faculty of Sciences; 24157 Douala Cameroon
3. School of Pharmacy, Faculty of Science and Engineering; University of Wolverhampton; Wulfruna Street Wolverhampton WV1 1LY UK