2-[amino-(4-amino-4-carboxy-butyl)imino-methyl]aminobutanedioic acid

Argininosuccinic acid participates in the fourth step of the urea cycle, with being cleaved to arginine and fumaric acid by argininosuccinic acid lyase (ASL). Argininosuccinic acid reduces reduced glutathione (GSH) level, and increases the production of reactive oxygen species in cerebral cortex and striatum. Argininosuccinic acid causes lipid peroxidation and protein oxidation, and induces oxidative stress in the developing rat brain[1][2].

A likely impurity is fumaric acid. In neutral or alkaline solution it readily undergoes ring closure to the 'anhydride' (see below). Crystallise it from water by adding 1.5 volumes of EtOH. The barium salt is stable at 0-5o if dry. [Westfall Biochem J 77 135 1960, Ratner & Kunkemueller Biochemistry 5 1821 1966.]

[1] Seminotti B, et al. Free Radical Scavengers Prevent Argininosuccinic Acid-Induced Oxidative Stress in the Brain of Developing Rats: a New Adjuvant Therapy for Argininosuccinate Lyase Deficiency Mol Neurobiol. 2020 Feb;57(2):1233-1244. DOI:10.1007/s12035-019-01825-0
[2] Nagamani SCS, et al. GeneReviews [Internet]. Seattle (WA): University of Washington, Seattle; 1993–2023. PMID:21290785