1. Research Institute of General Education and School of Agriculture, Kyushu Tokai University, Choyo 5435, Aso, Kumamoto 869-1404, Japan, Yoshitomi Pharmaceutical Co., Ltd., Yoshitomi 955, Chikujo, Fukuoka 871-8550, Japan, and Faculty of Pharmaceutical Sciences, Kumamoto University, Oe-honmachi 5-1, Kumamoto 862-0973, Japan