1. National Industrial Research Institute of Nagoya, Hirate-cho 1-1, Kita-ku, Nagoya City, Aichi Prefecture 462, Japan, Institute of Bioorganic Chemistry and Petrochemistry, Ukrainian Academy of Sciences, Kiev 253160, Ukraine, Central Research Laboratories of Ajinomoto Co., Inc., Suzukicho, Kawasaki 210, Japan, and Department of Chemistry, Faculty of Science, Kyoto University, Sakyo, Kyoto 606-01, Japan