Affiliation: | 1. University Chemical Laboratory, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW (UK), Fax: (+44)?1223‐336362;2. Present address: Medical Science Division, 3rd Patent Examination Department (Japan) Patent Office 4‐3, Kasumigaseki 3‐chome, Chiyoda‐ku, Tokyo 100‐8915 (Japan) |