1. Department of Biochemistry and Molecular Biology; Dalhousie University; Halifax Nova Scotia B3H 4R2 Canada
2. Faculty of Pharmacy; The British University in Egypt; 11837 Cairo Egypt
3. Department of Chemistry; University of Waterloo; Waterloo Ontario N2L 3G1 Canada
4. Department of Chemistry; Dalhousie University; Halifax Nova Scotia B3H 4R2 Canada