Mitochondrial disorders brain disease therapeutic agent and a diagnostic agent

The present invention provides a therapeutic agent and a diagnostic agent for brain diseases represented by cerebral infarction. [Solution] (A) General formula (1) R 2 R 1 NCH 2 COCH 2 CH 2 COR 3 (1) (Wherein R 1 and R 2 each independently represents a hydrogen atom, an alkyl group, an acyl group, an alkoxycarbonyl group, an aryl group or an aralkyl group; R 3 represents a hydroxy group, an alkoxy group, an acyloxy group, an alkoxycarbonyloxy group) A group, an aryloxy group, an aralkyloxy group or an amino group.) A therapeutic agent for brain diseases of mitochondrial disorder characterized by combining δ-aminolevulinic acid, a derivative thereof or a salt thereof represented by: and (B) an iron compound. [Selection figure] None