1. Faculty of Agriculture Shizuoka University Shizuoka422‐8529Japan
2. Department of Biochemistry Okayama University of Science 1‐1 Ridai‐cho Okayama700‐0005Japan
3. Department of Agricultural Chemistry School of AgricultureMeiji University 1‐1‐1 Higashimita, Tama‐ku Kawasaki Kanagawa214‐8571Japan
4. Department of Chemistry Graduate School of ScienceTohoku University Sendai980‐8578Japan
5. Center for Bioscience Research and Education Utsunomiya University 350 Mine‐cho Utsunomiya, Tochigi321‐8505Japan