1. Department of Chemistry, Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi, Osaka 558-8585, Japan
2. Saito Laboratory, Japan Food Research Laboratories, 4-41 Saito-asagi 7-chome, Ibaraki-shi, Osaka 567-0085, Japan
3. Department of Biology, Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi, Osaka 558-8585, Japan