1. Institute for Comprehensive Agricultural Sciences and Faculty of Agriculture, Kinki University, Nakamachi 3327-204, Nara 631-8505, Japan, Joint Research Center, Kinki University, Kowakae 3-4-1, Higashi-Osaka 577-8502, Japan, and Research Department, Sawai Pharmaceutical Company, Ltd., Ikue 1-8-14, Asahi-ku, Osaka 535-0004, Japan