1. Department of Pharmacognosy, Tohoku Pharmaceutical University, 4-1 Komatsushima 4-chome Aoba-ku, Sendai 981-8558, Japan, School of Pharmaceutical Sciences, University of Shizuoka, 52-1, Yada, Suruga-ku, Shizuoka 422-8526, Japan, and Institute for Environmental Sciences, University of Shizuoka, 52-1, Yada, Suruga-ku, Shizuoka 422-8526, Japan