Dihydrocitrinone is an organic compound belonging to the m-phthalate ester class and structurally characterized by a benzene-1,3-dicarboxylic acid–derived scaffold, with the specific moiety described as 3,4-dihydro-6,8-dihydroxy-3,4,5-trimethyl-isocoumarin-7-carboxylic acid. Dihydrocitrinone is effectively neutral due to its very weak basicity and has been detected in human blood as an exposure biomarker rather than an endogenous metabolite, appearing exclusively in individuals exposed to industrial or environmental chemicals.