[1] Hoshi Univ, Inst Med Chem, Tokyo 142, Japan
[2] Asadaame Co Ltd, Tokyo, Japan
[3] Hokkaido Natl Agr Expt Stn, Potato Breeding Lab, Eniwa, Hokkaido, Japan
[4] Nagasaki Agr & Forestry Expt Stn, Potato Branch, Nagasaki, Japan
[5] Wada Sugar Refining Co Ltd, Tokyo, Japan
[6] Meiji Gakuin Univ, Chem Lab, Yokohama, Kanagawa, Japan