1. a Kyoritsu University of Pharmacy , Shibakoen 1-5-30, Minato-ku, Tokyo, 105-8512, Japan
2. b Division of Pharmaceutical Organic Chemistry , Faculty of Pharmaceutical Sciences, Tokyo University of Science , Yamazaki 2641, Noda-shi, Chiba, 278-8510, Japan
3. c Keio University , Shibakoen 1-5-30, Minato-ku, Tokyo, 105-8512, Japan