1. Department of Chemistry, Université de Montréal, Station Centre-Ville, C.P. 6128, Montreal, QC, H3C 3J7, Canada
2. Microbiology, Bioorganic & Macromolecular Chemistry, Faculty of Pharmacy, Université Libre de Bruxelles, Bd du Triomphe, 1050 Brussels, Belgium
3. Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095-1569, USA