1. Department of Chemistry, University of Minnesota, Minneapolis, MN 55455 (USA), Fax: (+1) 612‐626‐7541
2. AstraZeneca Pharmaceuticals, 1800 Concord Pike, Wilmington, DE 19850 (USA)
3. Shionogi BioResearch Corp., 45 Hartwell Ave., Lexington, MA 02173 (USA)