1 Laboratory of Bioorganic Chemistry, Graduate School of Agriculture and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan. Electronic address: a-ykato@g.ecc.u-tokyo.ac.jp.
2 Laboratory of Bioorganic Chemistry, Graduate School of Agriculture and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan. Electronic address: a-fujii@g.ecc.u-tokyo.ac.jp.