235 °C, 508 K, 455 °F
Succinic acid (pronounced /səkˈsɪnɨk/; IUPAC systematic name: butanedioic acid; historically known as spirit of amber) is a dicarboxylic acid. Succinate plays a biochemical role in the citric acid cycle. The name derives from Latin succinum, meaning amber, from which the acid may be obtained.
The carboxylate anion is called succinate and esters of succinic acid are called alkyl succinates.
At room temperature, pure succinic acid is a solid that forms colorless, odorless crystals. It has a melting point of 185 °C and a boiling point of 235 °C. It is a diprotic acid.
Succinate is a component of the citric acid cycle and is capable of donating electrons to the electron transport chain by the reaction:
This is catalysed by the enzyme succinate dehydrogenase (or complex II of the mitochondrial ETC). The complex is a 4 subunit membrane-bound lipoprotein which couples the oxidation of succinate to the reduction of ubiquinone. Intermediate electron carriers are FAD and three Fe2S2 clusters part of subunit B.
Spirit of amber was procured from amber by pulverising and distilling it using a sand bath. It was chiefly used externally for rheumatic aches and pains, and internally in inveterate gleets.
The acid is combustible and corrosive, capable of causing burns.
In nutraceutical form as a food additive and dietary supplement, is safe and approved by the U.S. Food and Drug Administration. As an excipient in pharmaceutical products it is used to control acidity and, more rarely, in effervescent tablets.
Full article ▸