Development of 2-thioxoquinazoline-4-one derivatives as dual and selective inhibitors of dynamin-related protein 1 (Drp1) and puromycin-sensitive aminopeptidase (PSA).

An established inhibitor of dynamin-related protein 1 (Drp1), 3-(2,4-dichloro-5-methoxyphenyl)-2-thioxoquinazoline-4-one (mdivi-1), was recently reported also to show potent puromycin-sensitive aminopeptidase (PSA)-inhibitory activity. Herein, we report structural development of mdivi-1 derivatives and structure-activity relationship (SAR) analysis of the synthesized compounds, as well as the structurally related PSA-specific inhibitor 3-(2,6-diethylphenyl)quinazoline-2,4-dione (PAQ-22), with the aim of identifying key structural features for inhibitory activity in order to develop selective inhibitors of Drp1, which is a potential target for treatment of Huntington's disease. Among the synthesized compounds, 3-(4-chloro-3-methoxyphenyl)-2-thioxoquinazoline-4-one (10g) exhibited more potent Drp1-inhibitory activity than mdivi-1 with high selectivity for Drp1 over PSA.