1. Department of Chemistry, Graduate School of Science; Kyoto University; Sakyo-Ku, Kyoto 606-8502 Japan
2. Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering; Kyoto University; Nishikyo-Ku, Kyoto 615-8510 Japan
3. Department of Biotechnology, College of Life Sciences; Ritsumeikan University; Kusatsu Shiga 525-8577 Japan