1. Department of Bioorganic ChemistryOsaka University of Pharmaceutical Sciences 4-20-1 Nasahara, Takatsuki Osaka 569-1094 Japan
2. Present address: Graduate School of Pharmaceutical SciencesOsaka University 1–6 Yamadaoka, Suita Osaka 565-0871 Japan
3. Department of Applied ChemistryFaculty of ScienceTokyo University of Science 1-3 Kagurazaka, Shinjuku-ku Tokyo 162-8601 Japan
4. Department of Material and Life ChemistryFaculty of EngineeringKanagawa University 3-27-1 Rokkakubashi Kanagawa-ku, Yokohama 221-8686 Japan