1. Department of Macromolecular Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka 560-0043, Japan
2. Faculty of Pharmacy, Department of Chemistry, University of Montreal, CP 6128 Succursale Centre Ville, Montreal, Quebec Canada H3C 3J7
3. Department of Chemistry, University of Helsinki, P.O. Box 55 (A.I. Virtasen aukio1), FI-00014 Helsinki, Finland