1. Laboratory of Molecular Structure and Biological Function, Graduate School of Pharmaceutical Sciences, Chiba University, Yayoi-cho, 1-33, Inage-ku, Chiba 263-8522, Japan, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok 10330, Thailand, Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, Chiba University, Yayoi-cho, 1-33, Inage-ku, Chiba 263-8522, Japan