Showing chemical card for Isocitric acid (CFc000000125)
Record Information
Version
1.0
Creation Date
2022-08-28 10:25:12 UTC
Update Date
2022-09-13 18:44:26 UTC
Chemfont ID
CFc000000125
Molecule Identification
Common Name
Isocitric acid
Definition
Isocitric acid, also known as isocitrate belongs to the class of organic compounds known as tricarboxylic acids and derivatives. These are carboxylic acids containing exactly three carboxyl groups. Isocitric acid is a TCA (tricarboxylic acid) cycle intermediate. It is a structural isomer of citric acid and is formed from citrate with the help of the enzyme aconitase. More specifically, Isocitric acid is synthesized from citric acid via the intermediate cis-aconitic acid by the enzyme aconitase (aconitate hydratase). Isocitrate is acted upon by isocitrate dehydrogenase (IDH) to form alpha-ketoglutarate. This is a two-step process, which involves oxidation of isocitrate to oxalosuccinate (a ketone), followed by the decarboxylation of the carboxyl group beta to the ketone, forming alpha-ketoglutarate. In humans, IDH exists in three isoforms: IDH3 catalyzes the third step of the citric acid cycle while converting NAD+ to NADH in the mitochondria. The isoforms IDH1 and IDH2 catalyze the same reaction outside the context of the citric acid cycle and use NADP+ as a cofactor instead of NAD+. They localize to the cytosol as well as the mitochondrion and peroxisome. Isocitric acid exists in all living species, ranging from bacteria to plants to humans. Isocitric acid is a minor organic acid found in most fruit juices, especially in blackberries, youngberries, and boyberries, and in vegetables, especially in carrots. The determination of D-isocitric acid has become of importance in the analysis of fruit juices for the detection of illegal additives (adulteration). Since the quantities of citric and isocitric acids are correlated in fruit juices, a high ratio of citric to isocitric acid can indicate the addition of citric acid as an alduterant. In authentic orange juice, for example, the ratio of citric acid to D-isocitric acid is usually less than 130. Isocitric acid is mostly used in the food industry (food additive) as a food acidulant.
Belongs to the class of organic compounds known as tricarboxylic acids and derivatives. These are carboxylic acids containing exactly three carboxyl groups.
Finogenova, T. V.; Kamzolova, S. V.; Dedyukhina, E. G.; Shishkanova, N. V.; Il'chenko, A. P.; Morgunov, I. G.; Chernyavskaya, O. G.; Sokolov, A. P. Biosynthesis of citric and isocitric acids from ethanol by mutant Yarrowia lipolytica N 1 under continuous cultivation. Applied Microbiology and Biotechnology (2002), 59(4-5), 493-500.