1. Complex Carbohydrate Research Center; University of Georgia; 315 Riverbend Road Athens GA 30602 USA
2. Department of Chemistry; University of Georgia; Athens GA USA
3. Division of Chemical Biology and Medicinal Chemistry; Eshelman School of Pharmacy; University of North Carolina; Chapel Hill NC 27599 USA
4. Department of Chemical Biology and Drug Discovery; Utrecht Institute for Pharmaceutical Sciences, and Bijvoet Center for Biomolecular Research; Utrecht University; Universiteitsweg 99 3584 CG Utrecht The Netherlands