PROBLEM TO BE SOLVED: To provide a pharmaceutical composition for preventing and/or treating a neurodegenerative disease.SOLUTION: The pharmaceutical composition for preventing and/or treating a neurodegenerative disease contains a compound represented by formula (I) or a pharmaceutically acceptable salt thereof. (In the formula, R1, R2, R3, R4, R5, R6, the bonds including the broken-line parts, l, m and n are as described in the specification.)SELECTED DRAWING: NoneCOPYRIGHT: (C)2020,JPO&INPIT【課題】 神経変性疾患の予防及び/又は治療用医薬組成物を提供する。【解決手段】 式(I)(式中、R1、R2、R3、R4、R5、R6、破線部を含む結合、l、m、及びnは本明細書に記載されたとおりである)で示される化合物又はその薬学的に許容され得る塩を含有する、神経変性疾患の予防及び/又は治療用医薬組成物。【選択図】なし