1. Laboratory of Bioorganic Chemistry, University of Shizuoka, School of Pharmaceutical Sciences, Yada, Shizuoka 422, Japan
2. Osaka University, School of Medicine, Suita, Osaka 565, Japan
3. Pharmaceutical Research Center, Nisshin Flour Milling Co., Ltd., Irumagun, Saitama 356, Japan
4. Yanaihara Institute Inc., Fujinomiya, Shizuoka 418, Japan