Malic acid-d3 (Hydroxybutanedioic acid-d3) is the deuterium labeled Malic acid. Malic acid (Hydroxybutanedioic acid) is a dicarboxylic acid that is naturally found in fruits such as apples and pears. It plays a role in many sour or tart foods[1][2].

Stable heavy isotopes of hydrogen, carbon, and other elements have been incorporated into drug molecules, largely as tracers for quantitation during the drug development process. Deuteration has gained attention because of its potential to affect the pharmacokinetic and metabolic profiles of drugs[1].

[1]. Russak EM, et al. Impact of Deuterium Substitution on the Pharmacokinetics of Pharmaceuticals. Ann Pharmacother. 2019;53(2):211-216. [2]. Dai Z, et al. Current advance in biological production of malic acid using wild type and metabolic engineered strains. Bioresour Technol. 2018 Jun;258:345-353.