1. Gifu Pharmaceutical University, 6‐1 Mitahora‐higashi 5‐chome, Gifu 502‐8585, Japan, Fax: (internat.) +81‐58‐237‐5979
2. Chemistry Research Laboratories, Dainippon Pharmaceutical Co., Ltd., Enoki 33‐94, Suita, Osaka 564‐0053, Japan, Fax: (internat.) +81‐6‐6338‐7656