1. a Division of Life and Health Sciences, Joetsu University of Education, I, Yamayashiki, Joetsu, Niigata 943, Japan
2. b Division of Life and Health Sciences, Joetsu University of Education, I, Yamayashiki, Joetsu, Niigata 943, Japan
3. c Department of Chemistry and Chemical Engineering, Faculty of Engineering, Niigata University, 8050, Ikarashi 2-nocho, Niigata 950-21, Japan