PROBLEM TO BE SOLVED: To provide a glyoxalase I inhibitor that is a compound showing antitumor activity.SOLUTION: The present invention provides a glyoxalase I inhibitor comprising a compound represented by the following formula, and an antitumor agent.SELECTED DRAWING: NoneCOPYRIGHT: (C)2017,JPO&INPIT【課題】抗腫瘍活性を示す化合物である、グリオキサラーゼI阻害剤の提供。【解決手段】以下の式で代表される化合物を含むグリオキサラーゼI阻害剤及び抗腫瘍剤。【選択図】なし