<；P>；PROBLEM TO BE SOLVED: To provide a composition having excellent anticancer activity action, from potato skin and/or leaves and stalks of yacon (Polymnia sonchifolia). <；P>；SOLUTION: The composition compounded with an anticancer active ingredient derived from yacon preferably potato skins and/or leaves and stalks of the yacon, preferably a composition for treating or preventing diseases to be inhibited the cancer activity action is provided. The active ingredient is a fraction extracted from the yacon with a solvent. The solvent is hexane. The active ingredient uses 9-acetoxy-10-2,3-dimethyl-oxiranecarbonyloxy-4-methyl-12-methylene-13-oxo-3,14-dioxa-tricyclo[9.3.0.0<；SP>；2,4<；/SP>；]tetradec-7-ene-8-carboxylic acid methyl ester as an active ingredient for the activity action. The composition is a form selected from a group consisting of food additives, food materials, foods and drinks, medicines, quasi drugs and fodders, for suppressing cancer causing activity action. <；P>；COPYRIGHT: (C)2007,JPO&INPIT
