PROBLEM TO BE SOLVED: To provide a neprilysin enzyme inhibitor effective in treatment of diseases such as cardiovascular diseases, diarrhea, and renal diseases.SOLUTION: The invention provides compounds represented by formula (I) or pharmaceutically acceptable salts thereof.SELECTED DRAWING: None【課題】心血管疾患、下痢、腎疾患等の疾患の治療に有効なネプリライシン酵素阻害剤の提供。【解決手段】式(I)で表される化合物又は薬学的に許容されるその塩。【選択図】なし