1. Faculty of Pharmacy, Meijo University, Tempaku, Nagoya 468-8503, Japan, Tokai Gakuen University, Miyoshi, Aichi 470-0207, Japan, Okitsu Branch, Fruit Tree Research Station, Ministry of Agriculture, Forestry and Fisheries, Shimizu, Shizuoka 424-0204, Japan, and Department of Biochemistry, Kyoto Prefectural University of Medicine, Kamigyo-ku, Kyoto 602-0841, Japan