an organic tricarboxylic acid; one of the intermediate substrates of the tricarboxylic acid cycle.
Isocitric acid forms in an organism from citric acid and cisaconitic acid as a result of enzymatic conversion. With involvement of the enzyme isocitrate dehydrogenase, isocitric acid is converted, through oxalosuccinic acid, to α-ketoglutaric acid. With the aid of the enzyme isocitratelyase in the glyoxalate cycle, isocitric acid decomposes to succinic and glyoxylic acids.