1. Department of Biology, Osaka Dental University, 8-1, Kuzuha Hanazono-cho, Hirakata, Osaka 573-1121, Japan
2. Department of Chemistry, Osaka Dental University, 8-1, Kuzuha Hanazono-cho, Hirakata, Osaka 573-1121, Japan
3. Department of Applied Chemistry, Graduate School of Engineering, Osaka Metropolitan University, Gakuen-cho 1-1, Nakaku, Sakai, Osaka 599-8531, Japan