Decarboxylation


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Related to Decarboxylation: Decarboxylation reaction

Decarboxylation

 

the elimination of CO2 from the carboxyl group of carboxylic acids RCOOH. Heating such an acid with soda lime yields the hydrocarbon RH and CO2. Such carboxylic acids as cyanoacetic acid, CNCH2COOH, and malonic acid, CH2(COOH)2, lose CO2 upon simple heating. Upon treatment with concentrated H2SO4, oxalic acid yields CO, CO2, and water; formic acid yields CO2 and H2. Aromatic acids undergo decarboxylation when heated in quinoline in the presence of copper powder.

Fermentation decarboxylation plays an important part in metabolic processes. Amino acids are decarboxylated by decarboxylases, whose coenzyme is primarily phosphopyridoxal. Decarboxylation of amino acids is widespread among microorganisms, particularly the bacteria that are part of the microflora of the intestines of animals and man. Decarboxylation of a number of amino acids in animal tissues leads to formation of biogenic amines (histamine and serotonin, as well as γ-aminobutyric acid, taurine, and noradrenaline). The decarboxylation of α-keto acids is brought about by decarboxylases, whose coenzyme is thiamine pyrophosphate. The oxidation decarboxylation of pyrotartaric and α-ketoglutaric acids in animals and plants plays a large part in the Krebs cycle. In cells of microorganisms, pyrotartaric acid can be decarboxylated without access of oxygen, for example, in alcoholic fermentation.

References in periodicals archive ?
However, both PAAN and PANA are thermally more stable that PABA which may be due to the ease of decarboxylation.
Three possible reaction pathways are usually considered for the removal of oxygen during the hydrotreatment of triglycerides: hydrodeoxygenation, decarboxylation, and decarbonylation.
On the other hand, the acid pH of the resorptive lacunae induces osteocalcin decarboxylation [20, 24, 43, 44].
Gregory III, "Glycine turnover and decarboxylation rate quantified in healthy men and women using primed, constant infusions of [1,2-(13)C2]glycine and [(2)H3]leucine," Journal of Nutrition, vol.
Histamine is one of the weak known biogenic amine found in several foods such as fish products, cheese, wine, and fermented products and it is a product of microbial decarboxylation of histidine present in the foods (Bakirci et al, 2000).
(1,11) Positive PYR reaction and ornithine decarboxylation testing further differentiates S.
Ketosis (ketonemia and ketonuria) is a metabolic disorder in dairy animals caused by impaired metabolism of carbohydrate and volatile fatty acids leading to excessive production of ketone bodies: Acetoacetic acid, beta-hydroxybutyric acid and their decarboxylation products such as acetone and isopropanol (Radostits et al., 2000).
The mechanical changes caused by irradiation can be explained by the decarboxylation of the tissue.
This effect of malate on PSII activity might be the consequence of the accumulation of malate and pyruvate produced by malate decarboxylation. It may also result from a change in the NADPH/NADP ratio, because a large increase in this ratio was observed in leaves of Mal-treated plants (Fig.
The endogenous production of histamine comes from the decarboxylation of the amino acid histidine via the pyridoxal-5'-phosphate (vitamin B6) dependent enzyme histidine decarboxylase.
All suspected isolates were phenotypically identified as belonging to the BCC by oxidase, OF-glucose, sculin hydrolysis, lysine decarboxylation, and DNA hydrolysis tests, as well as by the semi-automatized API-20NE (BioMerieux Inc, Mercy Letoil, France) method.
cerevisiae can produce the vinylphenols through the decarboxylation of cinnamic acids (coumaric or ferulic).