1. Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-Cho, Tokushima 770-8514, Japan, Medicinal Chemistry Division, Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Jadavpur, Calcutta-700 032, India, and Laboratory of Cell Biology, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki Osaka, 569-1094, Japan