Phthalic anhydride was condensed with acetoacetic ester in acetic anhydride and triethylamine solution, and when phthalyl chloride was reacted with sodium acetoacetic ester compounds were formed of the phthalide and indandione series: phthalylacetoacetic ...

i.e., pyruvic acid, acetoacetic acid, and higher homologs. ... Abstract: ... keto acids, i.e., acetoacetic acid, levulinic acid, etc. ...

The role of ethanol O-d in nullifying the deuterolysis may be demonstrated by determining that transesterification of methyl acetoacetate of the ethyl ester occurs as well as deuterium exchange of the five acetoacetate hydrogens. The significant acidity of the methylene protons in the acetoacetate group, the efficacy of base catalysis, ...

A synthetic pathway consisting of octAB encoding succinyl-CoA:acetoacetate CoA-transferase and phaA encoding beta-ketothiolase from Ralstonia eutropha H16 was constructed in Escherichia coli for extracellular production of acetoacetate. The recombinant E. coli produced 8.2g/l acetoacetate in shake flasks at 37 degrees C in 24h. In a ...

The attempt to prepare toluene-2 C-14 starting from ethyl acetoacetate failed because the reaction of sodium ethyl acetoacetate with dibromopropane could not be performed. This labelling was also attempted starting from methyl tetrahydropyran. This synthe...

The reactions of picrylacetoacetic ester and picrylacetone with bases (alcoholates, amines, phosphine imine compounds) lead to deprotonation of the carbonyl part of the molecule. With the acetoacetic ester anion trinitrobenzene forms a stable 1:1 sigma complex at the ..cap alpha..-carbon atom.

A commercially available immobilized preparation of Rhizomucor miehei lipase (Lipozyme RMIM) has been employed in the synthesis of partial glycerides of acetoacetate. Due to the chemical reactivitity of the acetoacetyl group, these glycerides could have novel uses in e.g. polymer formation. Both 1...

Novel unusual microbial dehalogenation during enantioselective reduction of ethyl 4,4,4-trifluoro acetoacetate with baker�s yeast

Ketogenesis is usually measured in vivo by dilution of tracers of (3R)-hydroxybutyrate or acetoacetate. We show that, in perfused working rat hearts, the specific activities of (3R)-hydroxybutyrate and acetoacetate are diluted by isotopic exchanges in the absence of net ketogenesis. We call this process pseudoketogenesis. When hearts are perfused with ...

Human neutrophils by a chemiluminescence assay exhibit diminished phagocytic activity in the presence of abnormally high levels of the serum metabolite acetoacetate. These findings, along with our previous evidence demonstrating myeloperoxidase inhibition by acetoacetate, implicate metabolic ketosis in the inhibition of neutrophil microbicidal activity and ...

ethyl acetoacetate, followed by conversion to the semicarbazone,28whose specific radioactivity after ethyl aceto- acetate and preparation of the semicarbazone. The cyanoborohydride- acetoacetic ester acetoacetate followed by preparation and recrystallization of the semicarbazone showed that

In Clostridium acetobutylicum ATCC 824, acetoacetate decarboxylase (EC 4.1.1.4) is essential for solvent production, catalyzing the decarboxylation of acetoacetate to acetone. We report here the purification of the enzyme from C. acetobutylicum ATCC 824 and the cloning and expression of the gene encoding the acetoacetate decarboxylase ...

In Clostridium acetobutylicum ATCC 824, acetoacetate decarboxylase (EC 4.1.1.4) is essential for solvent production, catalyzing the decarboxylation of acetoacetate to acetone. We report here the purification of the enzyme from C. acetobutylicum ATCC 824 and the cloning and expression of the gene encoding the acetoacetate decarboxylase ...

Normally, the brain's fuel is glucose, but during fasting it increasingly relies on ketones (beta-hydroxybutyrate, acetoacetate, and acetone) produced in liver mitochondria from fatty acid beta-oxidation. Although moderately raised blood ketones produced on a very high fat ketogenic diet have important clinical effects on the brain, including reducing seizures, ketone ...

The metabolism of acetoacetate via a proposed cytosolic pathway in brain of 1-week-old rats was investigated. (-)-Hydroxycitrate, an inhibitor of ATP citrate lyase, markedly inhibited the incorporation of carbon from labelled glucose and 3-hydroxybutyrate into cerebral lipids, but had no effect on the incorporation of labelled acetate and acetoacetate into ...

It has been proposed that muscle is the site of net ketogenesis. This hypothesis was based on a discrepancy between the balance of unlabeled and labeled ketone bodies across muscle beds in humans infused with (/sup 14/C)acetoacetate. It has been pointed out that the dilution of the specific activity of acetoacetate could be explained by the reversal of ...

A simple and efficient method for the preparation of ?-stereogenic ?-keto esters is described using a copper(II)-catalyzed aerobic deacylation of substituted acetoacetate esters. The substrates for the title process arise from catalytic, enantioselective conjugate additions and alkylation reactions of acetoacetate esters. The mild conditions do not induce ...

A novel approach to the synthesis of purines bearing functionalized carbon substituents or methyl in position 6 was developed. Under different reaction conditions, 6-halopurine derivatives could react with ethyl acetoacetate efficiently to yield 2-(purin-6-yl)acetoacetic acid ethyl esters, (purin-6-yl)acetates and 6-methylpurines respectively. No metal ...

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A liquid phase extraction process is described for the dearomatization of a mixed hydrocarbon feed containing aromatic and nonaromatic hydrocarbons consisting of: (a) contacting the mixed feed in an extraction zone with the solvent ethyl acetoacetate at an elevated temperature to provide an aromatic-rich ethyl acetoacetate solvent phase containing the ...

Inhibition of glucose uptake by acetoacetate and relief of this inhibition by insulin found previously in slices of rat mammary gland [Williamson, McKeown & Ilic (1975) Biochem. J. 150. 145-152] was confirmed in acini, which represent a more homogeneous population of cells. Glycerol (1mM) behaved like insulin (50 minuits/ml) in its ability to relieve the inhibition of ...

To determine the temporal relationship between changes in contractile performance and flux through the citric acid cycle in hearts oxidizing acetoacetate, we perfused isolated working rat hearts with either glucose or acetoacetate (both 5 mM) and freeze-clamped the tissue at defined times. After 60 min of perfusion, hearts utilizing ...

Absent among (today's) critically important biological compounds reported in carbonaceous meteorites are keto acids, i.e., pyruvic acid, acetoacetic acid, ...

A highly stereoselective method for preparing ( Z)- and ( E)-enol triflates derived from substituted acetoacetate derivatives is described. The salient feature of this methodology is the use of Schotten-Baumann-type conditions to control enolate geometry using either aqueous LiOH ( Z-selective) or aqueous (Me)(4)NOH ( E-selective) in combination with triflic anhydride to ...

Myocardial glucose use is regulated by competing substrates and hormonal influences. However, the interactions of these effectors on the metabolism of exogenous glucose and glucose derived from endogenous glycogen are not completely understood. In order to determine changes in exogenous glucose uptake, glucose oxidation, and glycogen enrichment, hearts were perfused with glucose (5 mM) either ...

The authors have found that ethyl acetoacentate (EAA) and acetylacetone add to the double bond of acrylic monomers in the presence of the initiating system Fe(CO)/sub 5/ + Br/sub 2/(IS). The iron pentacarbonyl-bromine system initiates the addition reactions of ethyl acetoacetate and acetylacetone with the double bonds of acrylic monomers.

The properties of Raney nickel catalysts modified by (+)-tartaric acid and active in enantioselective hydrogenation of ethyl acetoacetate depend on the chemical and phase compositions of the starting Ni-Al alloys. A decrease of the Ni content in the Ni-Al alloy specimens which corresponds to an increase of the fraction of the NiAl/sub 3/ intermetallic compound in them ...

The rates of transport and oxidation of acetoacetate have been measured in seven anesthetized, pancreatectomized, ketotic dogs using a constant infusion of acetoacetate-3-¹⁴C. Control experiments were performed in 14 normal dogs. In addition to the acetoacetate-¹⁴C, the latter were infused ...

New aliphatic polyester-type dendrimers were synthesized using a new AB2-type building block 3, prepared from benzyl acetoacetate and 2 equiv of tert-butyl acrylate by acetoacetic acid ester synthesis. The reiterative [deprotection by HCO2H, then EDCI/DMAP coupling] sequence using divergent growth method gave [G1]-4tBu-[G5]-64tBu dendrimers. 13C NMR ...

>Acid dissociation constants of some BETA -keto esters, viz. ethyl acetoacetate, ethyl alpha -phenyl acetoacetate, ethyl alpha - gamma -diphenyl acetoacetate, ethyl alpha -phenyl)phenylpropioloylacetate, ethyl alpha ( alpha -naphthyl)phenylpropioloylacetate, have been determined potentiometrically in 75 vol% ...

... Methyl hexyl carbinol 26.5 dynes/cm Isoamyl alcohol 24.1 11 If Tert ... acetone , amyl acetate , cel losolve Acetate , ethyl acetoacetate , butyl or piropyl ...

It was found possible to obtain coordination polymers by polyrecombination (4.4'-bis(acetoacetyl) phenyl ether + Be); by the reaction of ethers with terminal acetoacetate groups having metallic derivatives (diacetate acetones of N-xylyleneglycol and di-(b...

Type-1 diabetic patients experience hyperketonemia caused by an increase in fatty acid metabolism. Thus, the aim of this study was to measure the effect of ketone bodies as suppressors of oxidizing species produced by stimulated neutrophils. Both acetoacetate and 3-hydroxybutyrate have suppressive effect on the respiratory burst measured by luminol-enhanced chemiluminescence. ...

Diets containing 0.2% theophylline were fed ad libitum to rats. The blood beta-hydroxybutyrate to acetoacetate ratio was significantly increased in rats receiving theophylline. The concentrations of blood glucose and liver glycogen were significantly decr...

A novel enzymatic reaction involved in the metabolism of aliphatic epoxides by Xanthobacter strain Py2 is described. Cell extracts catalyzed the CO2-dependent carboxylation of propylene oxide (epoxypropane) to form acetoacetate and beta-hydroxybutyrate. The time courses of acetoacetate and beta-hydroxybutyrate formaton indicate that ...

The formation of various alpha-diazo acetoacetic esters can be obtained in a single transformation with good to excellent yields using readily available 2-diazoacetoacetic acid. PMID:16538259

Palladium-catalyzed decarboxylative rearrangement of nonracemic phosphono allylic acetoacetates, or the intermolecular allylic substitution of nonracemic phosphono allylic carbonates with tert-butyl acetoacetate followed by hydrolysis and decarboxylation, gave omega-ketovinyl phosphonates. A highly regioselective Wacker oxidation gave the ...

Total ketone body specific activity has been widely used in studies of ketone body metabolism to circumvent so-called isotope disequilibrium between the two major ketone body pools, acetoacetate and beta-hydroxybutyrate. Recently, this approach has been criticized on theoretical grounds. In the present studies, (13C)acetoacetate and ...

We describe an integrated set of experiments for the undergraduate organic laboratory that allows students to compare and contrast biological and chemical means of introducing chirality into a molecule. The racemic reduction of ethyl acetoacetate with sodium borohydride and the same reduction in the presence of a tartaric acid ligand are described, and a capillary gas ...

An automated, one-pot radio-synthesis module for the routine preparation of 1-[(11)C]acetoacetic acid has been developed. The enolate anion of acetone was reacted with [(11)C]CO(2) in tetrahydrofuran (THF), followed by hydrolysis and purification by ion-exchange chromatography. The total synthesis time was 18 min and radiochemical yield was 34% after decay correction. HPLC ...

We hypothesized that contrasting leucine with its non-metabolizable analog 2-aminobicyclo[2,2,1]heptane-2-carboxylic acid (BCH) might provide new information about metabolic pathways involved in insulin secretion. Both compounds stimulate insulin secretion by allosterically activating glutamate dehydrogenase, which enhances glutamate metabolism. However, we found that leucine was a stronger ...

SummaryWe hypothesized that contrasting leucine with its non-metabolizable analog 2-aminobicyclo[2,2,1]heptane-2-carboxylic acid (BCH) might provide new information about metabolic pathways involved in insulin secretion. Both compounds stimulate insulin secretion by allosterically activating glutamate dehydrogenase, which enhances glutamate metabolism. However, we found that leucine was a stronger ...

Amino groups of amino acids, nucleic acids and lipids can react non-enzymatically with reducing sugars to form unstable Schiff bases that can then undergo the Amadori rearrangement to form irreversible advanced glycation end products (AGEs). Ketoacidosis is a life-threatening complication in patients with untreated diabetes mellitus and it is characterized by increased circulating ketone body ...

Development of a butanologenic strain with high selectivity for butanol production is often proposed as a possible route for improving the economics of biobutanol production by solventogenic Clostridium species. The acetoacetate decarboxylase (aadc) gene encoding acetoacetate decarboxylase (AADC), which catalyzes the decarboxylation of ...

Isolated suspensions of colonocytes from the rat were used to assess utilization, interaction, and fate of metabolic substrates normally obtained from colonic bacteria (acetate, propionate, butyrate) or derived from the blood circulation to the colonic mucosa (D-glucose, acetoacetate, L-glutamine). The short-chain fatty acid n-butyrate (10 mM), on its own, accounted for 86% of ...

We have directly tested the ability of acetoacetate, upon activation to the CoA thioester, to channel into the cholesterogenic pathway prior to scrambling of its carbon skeleton with the acetate pool. The approach relies upon trapping [3-13C]acetoacetate-derived hydroxymethylglutaryl-CoA, hydrolyzing this metabolite, and esterifying the resulting ...

We show here an efficient synthesis system of isoprenoids from acetoacetate as the main substrate. We expressed in Escherichia coli a Streptomyces mevalonate pathway gene cluster starting from HMG-CoA synthase and including isopentenyl diphosphate isomerase (idi) type 2 gene and the yeast idi type 1 and rat acetoacetate-CoA ligase (Aacl) genes. When the ...

Anaplerosis, the net synthesis in mitochondria of citric acid cycle intermediates, and cataplerosis, their export to the cytosol, have been shown to be important for insulin secretion in rodent beta cells. However, human islets may be different. We observed that the enzyme activity, protein level, and relative mRNA level of the key anaplerotic enzyme pyruvate carboxylase (PC) were 80-90% lower in ...

Mn-doped ZnO samples with 5%, 20% and 40% nominal Mn concentrations were prepared in the presence of ethyl acetoacetate under solvothermal conditions. UV absorption spectroscopic analysis discloses that chemical modification was achieved by reaction of Zn or Mn precursor with ethyl acetoacetate in ethanol medium. XRD and HRTEM characterizations indicate ...

1. A technique for perfusing the isolated rat kidney is described. It is primarily designed for the study of renal metabolism but is also suitable for studying some aspects of the secretory function; this was normal with respect to minimal glucosuria. The glomerular filtration rate as measured by creatinine clearance was lower than in vivo and slowly decreased with time. 2. Gluconeogenesis from a ...

Formation of wine pyranoanthocyanins in model wine was monitored by HPLC-DAD-ESI-MS/MS, using red grape skin extracts and wine fermentation metabolites (acetaldehyde, pyruvic and acetoacetic acids, and diacetyl) and also hydroxycinnamic acids (p-coumaric, caffeic, ferulic, and sinapic acids). Pyruvic acid and acetaldehyde reacted fast, the first reaching high product yield and ...

The effects of acetoacetic acid, acetone, bilirubin, beta-carotene, three cephalospoprin antibiotics, glucose, hemoglobin and lipid on the kinetic Jaff� reaction and an enzymatic reaction for the determination of creatinine concentration were studied in bovine, canine, feline and equine serum. There were no obvious species' differences. The kinetic Jaff� reaction was ...

A gas chromatography-mass spectrometry (GC-MS) method for determination of ketone bodies (?-hydroxybutyrate, acetone, and acetoacetate) in blood is presented. The method is based on enzymatic oxidation of D-?-hydroxybutyrate to acetoacetate, followed by decarboxylation to acetone, which was quantified by the use of headspace GC-MS using acetone-(13)C(3) as ...

To compare the powers of the corresponding enzymes as catalysts, the rates of uncatalyzed decarboxylation of several aliphatic acids (oxalate, malonate, acetoacetate, and oxaloacetate) were determined at elevated temperatures and extrapolated to 25 �C. In the extreme case of oxalate, the rate of the uncatalyzed reaction at pH 4.2 was 1.1 � 10(-12) s(-1), implying a 2.5 � ...

An extension of the classic keto-enol tautomerization of beta-dicarbonyl compounds into a kinetic analysis of deuterium exchange is presented. It is shown that acetylacetone and ethyl acetoacetate undergo nearly complete deuterium exchange of the alpha-methylene carbon when dissolved in methanol-d[subscript 4]. The extent of deuteration may be monitored via NMR spectroscopy as ...

The aim of this study is to elucidate the property of enzymes specifically involved in the formation of acetone, butanol, and isopropanol in Clostridium beijerinckii (formerly C. butyricum). Specifically to determine whether one or two alcohol dehydrogenases were involved in the formation of butanol and isopropanol and to identify and characterize the enzyme converting acetoacetyl CoA to ...

Hepatic microsomal enzyme activity was induced in wild-trapped raccoons (Procyon lotor) and selected blood characteristics were measured in an effort to detect responses due to PCB ingestion, nutritional restriction, and their interactions. Barbiturate-induced sleeping times were used as an index of hepatic microsomal activity because they have been used reliably by other workers. Blood ...

1. The synthesis of phosphoenolpyruvate and the O₂ consumption from the tricarboxylic acid-cycle intermediates citrate, ?-oxoglutarate, malate and succinate by guinea-pig mitochondria were compared. Malate was the most effective of these precursors; there was no synthesis of phosphoenolpyruvate from succinate. 2. The addition of palmitate, acetoacetate ...

The reduction of ethyl acetoacetate using common baker's yeast is a traditional experiment that shows the stereoselective power of a biochemical system. Addition of organic solvents to aqueous reaction system increased the yields and reproducibility of the experiment thus overcoming the two problems associated with the experiment, low yield, and the analysis of ...

Through a biomimetic pathway, hyperolactone D, 4-hydroxyhyperolactone D, and hyperolactone C were synthesized from methyl acetoacetate via Weiler's dianion method, asymmetric allylic alkylation, biomimetic lactonization, oxidation, and cyclization. The stereochemistry of the quaternary carbon was controlled efficiently by Palladium-catalyzed asymmetric allylic alkylation. This ...