Этил пирува

Химические свойства

Ethyl pyruvate has a vegetable, caramel odor.

Вхождение

Reported found in Parmesan cheese, cognac, grape wines, cocoa and mushrooms.

Использование

Ethyl pyruvate (EP) has demonstrated neuroprotective effects against acute brain injury through its anti-inflammatory action.

Подготовка

By direct esterification of pyruvic acid with absolute ethyl alcohol at the boil and subsequent vacuum distillation; by esterification via oxidation of vapors of ethyl lactate in the presence of V2O5 at 155°C

Общее описание

Ethyl pyruvate is a volatile aliphatic ester of the pyruvate metabolite. It is present as a food additive/odor-active component in various food and beverage products. It is also used as an inhibitory odorant to repel the insects from human proximity.

Методы очистки

Shake the ester with 10mL portions of saturated aqueous CaCl2 solution (removes ethyl acetate) and the organic layer is removed by centrifugation, decantation and filtration, and is distilled under reduced pressure. Purification of small quantities is carried out via the bisulfite adduct: the ester (2.2mL) is shaken with saturated NaHSO3 (3.6mL), chilled in a freezing mixture when crystals separate rapidly (particularly if seeded). After 5minutes EtOH (10mL) is added and the crystals are filtered off, washed with EtOH and Et2O and dried. Yield ca 3g of bisulfite adduct. Then treat the adduct (16g) with saturated aqueous MgSO4 (32mL) and 40% formaldehyde (5mL) and shake, whereby the ester separates as an oil which is extracted with Et2O. The extract is dried (MgSO4), filtered, evaporated and the residue is distilled (b 56o/20mm), and then redistilled (b 147.5o/750mm) to give 5.5g of pure ester. [Cornforth Org Synth Coll Vol IV 467 1963, Beilstein 3 IV 1513.]