Formate
Formate (IUPAC name: methanoate) is the anion derived from formic acid. Its formula is represented in various equivalent ways: CHOO− or HCOO− or HCO2−. It is the product of deprotonation of formic acid. It is the simplest carboxylate anion. A formate (compound) is a salt or ester of formic acid.
Biochemistry
Formate is produced in large amounts in the hepatic (liver cells) mitochondria of embryonic cells and in cancer cells by the folate cycle.[1]
Formate is reversibly oxidized by the enzyme formate dehydrogenase from Desulfovibrio gigas:[2]
- HCO2− → CO2 + H+ + 2 e−
Formate esters and salts
Formate esters have the formula ROC(O)H (alternative way of writing formula RO2CH). Many form spontaneously when alcohols dissolve in formic acid.
Formate salts have the formula M(O2CH). Such salts are prone to decarboxylation. For example, hydrated nickel formate, a salt, decarboxylates at about 200 °C to give finely powdered nickel metal:
- Ni(O2CH)2(H2O)x → Ni + 2 CO2 + x H2O + H2
Such fine powders are useful as hydrogenation catalyst.
Examples
- ethyl formate, CH3CH2(HCOO)
- sodium formate, Na(HCOO)
- caesium formate, Cs(HCOO); see Caesium: Petroleum exploration
- methyl formate, CH3(HCOO)
- methyl chloroformate, CH3OCOCl
- triethyl orthoformate
- trimethyl orthoformate, C4H10O3
References
- ↑ H Frederik Nijhout, et al, In silico experimentation with a model of hepatic mitochondrial folate metabolism, Theoretical Biology and Medical Modeling, 2006, 3:40, link http://www.tbiomed.com/content/3/1/40/abstract).
- ↑ T. Reda, C. M. Plugge, N. J. Abram and J. Hirst, "Reversible interconversion of carbon dioxide and formate by an electroactive enzyme", PNAS 2008 105, 10654–10658. doi:10.1073/pnas.0801290105