1. Department of Biological Sciences, Graduate School of Science, University of Tokyo, Tokyo 113-0033, Japan
2. Department of Biological Sciences, Faculty of Science and Engineering, Chuo University, Tokyo 112-8551, Japan
3. Chemical Resources Laboratory, Tokyo Institute of Technology, Yokohama 226-8503, Japan
4. Department of Biological Science and Chemistry, Faculty of Science, Graduate School of Medicine, Yamaguchi University, Yamaguchi 753-8512, Japan
5. Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA