P-Ketoglutaric acid

Acetone, acetonyl-. See 2,5-Hexanedione Acetone chloroform. See Chlorobutanol hemihydrate Chlorobutanol Acetone cyanhydrin Acetone cyanohydrin. See 2-Hydroxy-2-methylpropanenitrile Acetonedicarboxylic acid Acetone-1,3-dicarboxylic acid. See P-Ketoglutaric acid Acetone dimethyl acetal. See Dimethoxypropane Acetone/diphenylamine condensate Acetone/diphenylamine condensates. See Di phenylam i ne-acetone Acetone/formaldehyde condensate CAS 25619-09-4 Uses In food-pkg. adhesives Regulatory FDA 21CFR 175.105... 

N-Acyl glutamic acid diamide. See Acyl glutamic acid diamide ADA. See P-Ketoglutaric acid Azodicarbonamide P-ADA. See P-Alanine diacetic acid 1-Adamantanecarboxylic acid ethyl ester. See Ethyl tricyclodecanecarboxylate Adame. See Dimethylaminoethyl acrylate ADC. See Azodicarbonamide Addeo DF-1] Addeo DF-2] Addeo DF-3. See Tallamide DIPA... 

Isopropylcyclohexane Isopropylcyclopentane Isoquinoline p-Ketoglutaric acid Levulinic acid... 

Because citric acid is considered as relatively cheap and abundant material, it was catalytically dehydrated to aconitic acid in the 120-150 °C temperature range by Umbdenstock and Bruin [61]. Aconitic acid can be readily decaiboxylated to a mixture of isomeric itaconic acids (itaconic, citraconic and mesaconic acids). These acids and their esters are nsed to produce alkyl resins and plasticizers. The mechanism of thermal rearrangement of citraconic acid to itaconic acid in aqueous solution was in a great detail investigated by Sakai [62]. In some cases, the applied catalyst caused excessive pyrolysis of citric acid and in the dehydration and decarboxylation reactions acetone dicarboxylic acid (P-ketoglutaric acid) was initially formed and from it acetone. The catalytic pyrolysis of citric acid monohydrate heated up to 140 °C to obtain itaconic and citraconic acids was reported by Askew and Tawn [63],... 

B. a-Ketoglularic acid. The ester obtained by the foregoing procedure is mixed with 600 ml. of concentrated hydrochloric acid and left overnight. The mixture is concentrated by distillation (Note 5) until the temperature of the liquid reaches 140°. It is poured into an evaporating dish and allowed to cool. The solid mass, weighing 11(3-112 g., is then pulverized. The yield of a-ketoglutaric acid is 92-93% of the theoretical for the last step, or 75-77% based upon diethyl succinate. The light tan product, obtained as described above, is suitable for most purposes, but a purer add, m.p. 109-110° (corr.) may be obtained by recrystallization from an acetone-benzene mixture. 

B. a-Ketoglutaric acid. A mixture of 225 g. (0.82 mole) of triethyl oxalylsuccinate, 330 ml. of 12N hydrochloric acid, and 660 ml. of water is heated under reflux for 4 hours, and the mixture is distilled to dryness under reduced pressure at a bath temperature of 60-70° (Note 4). The liquid residue, which solidifies readily on standing, is warmed with 200 ml. of nitroethane on a steam bath until it is in solution. The warm solution is filtered, the funnel is washed with 40 ml. of nitroethane, and the filtrate is stirred at 0-10° for 5 hours. a-Ketoglutaric acid is separated by filtration and dried at 90° under reduced pressure for 4 hours. It is obtained as a tan solid weight 88-99 g. (73-83%) m.p. 103-110° (Note 5). 

Dogra, J. V. V. and S. . P. Sinha. 1979. Observation of the age related changes in the level of alpha-ketoglutaric acid in leaves of Phyllanthus simplex (Retz.). Comp. Physiol. Ecol. 4 35-37. 

Other special injection devices have been applied in combination with derivatization only rarely, if the reaction is carried out directly in the injection port. The method of thermal degradation of quaternary ammonium salts has already been mentioned. This can be performed in a sealed capillary directly in the injection port of the apparatus. The port should then be modified in order that when the reaction is finished, the capillary can be crushed and the products swept into the column. Another method of modification of the injection port in the thermal decomposition of hydrazones by a-ketoglutaric acid is shown in Fig. 4.3 (p.77). 

Apart from the interferences that have been tabulated here, other substances have also been investigated and reported in the literature (see SlOO, S102). Unfortunately, these have not been quantified in detail, so that only qualitative information can be given. According to these reports, the following substances do not disturb the measurements benzyl penicillin, fructose, P-hy-droxybutyrate, a-ketoglutaric acid, lactate and phenacemide. 

Step 3 of Figure 29.12 Oxidation and Decarboxylation (2/, 3- )-Isocitrate, a secondary alcohol, is oxidized by NAD+ in step 3 to give the ketone oxalosuccinate, which loses CO2 to give o-ketoglutarate. Catalyzed by isocitrate dehydrogenase, the decarboxylation is a typical reaction of a p-keto acid, just like that in the acetoacetic ester synthesis (Section 22.7). The enzyme requires a divalent cation as cofactor, presumably to polarize the ketone carbonyl group. 

To date, four main types of catalytic activity have been reported in detail for thermal polyamino acids. These are (with the most studied substrates in parentheses) hydrolyses (p-nitrophenyl acetate, p-nitro-phenyl phosphate, ATP), decarboxylations (OAA, glucuronic acid, pyruvic acid), and aminations (a-ketoglutaric acid, OAA, pyruvic acid, phenylpyruvic acid). The fourth type is a deamination reaction yielding a-ketoglutaric acid (51). For some of the actions of the thermal polymers the products are identified quantitatively, and the kinds of amino acid side chain necessary for activity in the polymer elucidated. In others, products have yet to be fully identified. The activities of thermal polyamino acids are manifest on substrates which range from chemically labile to relatively stable. 

Cook et al. (93,94) obtained lactam 37a, in 82% yield, by refluxing N -benzyltryptamine (36a) and 2-ketoglutaric acid in toluene in the presence of p-toluenesulfonic acid. Then they oxidized 37a with SeO2 in dioxane. As a result, loss of the A -benzyl group and aromatization of ring C proceeded simultaneously, and canthin-6-one (1) was successfully synthesized in 33% yield. Under similar conditions, using N -benzyl tryptophan methyl ester (36b), 2-methoxycarbonylcanthin-6-one (38) was... 

The reaction of 2-ketoglutaric acid (84) with phosphorus trichloride in THF gave a mixture of three enantiomeric pairs (85a-c), as evidenced by H and NMR, which crystallized as (85c) identified by single-crystal X-ray analysis (Figure 1). After several hours in acetonitrile solution the crystals (with 8 P, —49.3) reverted to a mixture of the three isomers. The open enolate forms of the lactone rings (e.g. 85c ) were also detected in solution. The reaction of the spirophosphoranes with Sg in the presence of triethylamine to form (86), was also described." ... 

Ketoacid, oxoacid a carboxylic acid containing a carbonyl group (-C=0) in addition to the carboxyl group (COOH). Depending on the position of the carbonyl with respect to the carboxyl, the acid is referred to as an a-, 3- or y-ketoacid (2-, 3- or 4-oxo-acid). If the two groups are adjacent, the compound is called an a-K.a. or a 2-oxoacid (e.g. pyruvic acid and a-ketoglutaric acid) if they are separated by one CHj group, the compound is a p-K.a. or a 3-oxoacid (e.g. acetoacetie acid). 

The first step in tyrosine oxidation is a transamination to form p-hydroxyphenylpyruvic acid. Several groups of investigators independently showed a dependence of tyrosine oxidation on the presence of a keto acid. Knox and LeMay-Knox showed that a-ketoglutarate is a specific partner in the transamination and that pyridoxal phosphate is a cofactor in this reaction. Partial resolution of the transaminase allowed a demonstration of parallel restoration of transaminase activity and over-all tyrosine oxidation by addition of pyridoxal phosphate. 

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