1. Department of Pediatrics, Centre Hospitalier Universitaire (CHU) Sainte—Justine Research Center, Montréal H3T 1C5, Québec, Canada
2. Department of Chemistry—BMC, Uppsala University, Husargatan 3, Uppsala SE-752 37, Sweden
3. The Swedish NMR Centre, Medicinaregatan 5, Gothenburg SE-413 90, Sweden