1. Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada, Section MIG, Institute of Laboratory Medicine, Lund University, Sölvegatan 23, 223 62 Lund, Sweden, and Organic and Bioorganic Chemistry, Lund University, P.O. Box 124, 221 00 Lund, Sweden