Succinic acid

Succinic acid (/səkˈsɪnɪk/) is a dicarboxylic acid with the chemical formula (CH2)2(CO2H)2.[5] The name derives from Latin succinum, meaning amber. In living organisms, succinic acid takes the form of an anion, succinate, which has multiple biological roles as a metabolic intermediate being converted into fumarate by the enzyme succinate dehydrogenase in complex 2 of the electron transport chain which is involved in making ATP, and as a signaling molecule reflecting the cellular metabolic state.

It is marketed as food additive E363. Succinate is generated in mitochondria via the tricarboxylic acid cycle (TCA).

Succinate can exit the mitochondrial matrix and function in the cytoplasm as well as the extracellular space, changing gene expression patterns, modulating epigenetic landscape or demonstrating hormone-like signaling.

As such, succinate links cellular metabolism, especially ATP formation, to the regulation of cellular function. Dysregulation of succinate synthesis, and therefore ATP synthesis, happens in some genetic mitochondrial diseases, such as Leigh syndrome, and Melas syndrome, and degradation can lead to pathological conditions, such as malignant transformation, inflammation and tissue injury.

Succinic acid is a white, odorless solid with a highly acidic taste. In an aqueous solution, succinic acid readily ionizes to form its conjugate base, succinate (/ˈsʌksɪneɪt/).

Historically, succinic acid was obtained from amber by distillation and has thus been known as spirit of amber. Common industrial routes include hydrogenation of maleic acid, oxidation of 1,4-butanediol, and carbonylation of ethylene glycol. Succinate is also produced from butane via maleic anhydride.[10] Global production is estimated at 16,000 to 30,000 tons a year, with an annual growth rate of 10%.

Genetically engineered Escherichia coli and Saccharomyces cerevisiae are proposed for the commercial production via fermentation of glucose.