Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Dicarboxylic Acids”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources
PubMed1987

Capillary gas chromatographic-electron capture detection of coca-leaf-related impurities in illicit cocaine: 2,4-diphenylcyclobutane-1,3-dicarboxylic acids, 1,4-diphenylcyclobutane-2,3-dicarboxylic acids and their alkaloidal precursors, the truxillines.

A method has been developed that allows for the detection of the eleven stereoisomers of diphenylcyclobutanedicarboxylic acid in illicit cocaine samples, including alpha-, gamma-, and epsilon-truxillic acids and beta- and delta-truxinic acids. These, and other carboxylic acids, were also detected as ester moieties of alkaloidal impurities in illicit cocaine as well as in alkaloids of the South American coca leaf, e.g., alpha- and beta-truxilline. After lithium aluminum hydride reduction of the acidic and basic extracts of a prepared sample, the reduced species were derivatized with heptafluorobutyric anhydride in the presence of pyridine. The heptafluorobutyryl derivatives of the reduced diphenylcyclobutanedicarboxylic compounds were easily detected on-column at low picogram levels using a moderately polar fused-silica capillary column in the splitless mode and interfaced with a 63Ni electron-capture detector.

Alcohols↗
PubMed1984

Urinary excretion of dicarboxylic acids from patients with the Zellweger syndrome. Importance of peroxisomes in beta-oxidation of dicarboxylic acids.

The urinary excretion of adipic acid, suberic acid and sebacic acid from two patients with the cerebrohepato-renal syndrome of Zellweger was studied. The patients had a complete lack of peroxisomes in the liver as judged by electron microscopy. In the non-ketotic state, the total excretion of free and conjugated adipic acid, suberic acid and sebacic acid was increased by about 100%, 200% and 350%, respectively, as compared to the corresponding excretion from six healthy infants of the same age. The excretion of free dicarboxylic acid was increased to a considerably lesser extent than the free + conjugated dicarboxylic acid. In view of the presence of adipic acid in urine of the Zellweger patients, it is concluded that peroxisomes are not obligatory for beta-oxidation of medium-chain dicarboxylic acids in vivo. The relative accumulation of suberic acid and sebacic acid as compared to adipic acid is, however, consistent with a relative block in the conversion of suberic acid and sebacic acid into adipic acid in patients with the Zellweger syndrome.

Dicarboxylic Acids↗
PubMed1979

Dicarboxylic acid transport in Escherichia coli K12: involvement of a binding protein in the translocation of dicarboxylic acids across the outer membrane of the cell envelope.

We have previously found that the dicarboxylate transport system in Escherichia coli K12 is an active transport system and that at least one binding protein and two cytoplasmic membrane transport components are involved in the uptake of dicarboxylic acids. Recently, through surface labelling studies, some dicarboxylate binding proteins were found to be exposed on the cell surface. In the present paper, we demonstrate that the dicarboxylate transport component located in the outer membrane can be inactivated by two different kinds of nonpenetrating inhibitors, viz. proteases, and diazosulfanilic acid. These inhibitors seem to act on the dicarboxylate binding protein. By adding this protein to inactivated cells or to transport-negative mutants, we have succeeded in reconstituting the dicarboxylate transport system. These findings suggest that the dicarboxylate binding protein found on the cell surface plays an essential role in the translocation of dicarboxylic acids across the outer membrane.

Biological Transport, Active↗
PubMed1995

Mass spectral fragmentation patterns of some new 3,7-dichloro-benzo[1,2-b:4,5-b']dithiophene-2,6-dicarboxylic acid dianilides and 3,5-dichloro-dithieno[3,2-b:2',3'-d]thiophene-2,6-dicarboxylic acid dianilides. II.

The electron impact mass spectra of some benzo[1,2-b:4,5-b']dithiophene-2,6-dicarboxylic acid dianilides and dithieno[3,2-b:2',3'-d]thiophene-2,6-dicarboxylic acid dianilides are discussed. Dominant peaks in these dianilides are formed by the cleavage of a C-N bond on one side of an anilino group. These ions fragment further by the cleavage of a C-C bond on the other side of an anilino group and a CONRPhR' group may be lost directly. After loss of CO, the characteristic benzodithiophene radical cation, C10H2S2Cl2[symbol: see text], at m/z 256 and the dithienothiophene radical cation, C8S3Cl2[symbol: see text], at m/z 262 are formed from their respective precursor compounds.

Anilides↗
PubMed1989

Compartmentation of dicarboxylic acid beta-oxidation in rat liver: importance of peroxisomes in the metabolism of dicarboxylic acids.

Peroxisomal and mitochondrial beta-oxidation of dicarboxylic acids (DCAs) were investigated and compared. When isolated hepatocytes were incubated with DCAs of various chain lengths, H2O2 was derived from peroxisomal beta-oxidation, the rates of its generation being comparable to those seen with monocarboxylic acids (MCAs), whereas the rates of ketone body production, a measure of mitochondrial beta-oxidation, were much lower than those with MCAs. Peroxisomal beta-oxidation measured by cyanide-insensitive NAD reduction exhibited similar chain-length specificities for both dicarboxylyl-CoAs (DC-CoAs) and monocarboxylyl-CoAs (MC-CoAs), except that the activities for DC-CoAs with 10-16 carbon atoms were about half of those of the corresponding MC-CoAs. In contrast, mitochondrial beta-oxidation measured by antimycin A-sensitive O2 consumption had no activity for DCAs. In the study with purified enzymes, the reactivities of mitochondrial carnitine palmitoyltransferase and acyl-CoA dehydrogenase for DC-CoAs were much lower than those for MC-CoAs, while the reactivity of peroxisomal acyl-CoA oxidase for DC-CoAs was comparable to that for the corresponding MC-CoAs. Accordingly, the properties of carnitine palmitoyltransferase and acyl-CoA dehydrogenase must be the rate-limiting factors for mitochondrial beta-oxidation, with the result that DCAs might hardly be oxidized in mitochondria. Comparative study of beta-oxidation capacities of peroxisomes and mitochondria in the liver showed that DC12-CoA was hardly subjected to mitochondrial beta-oxidation, and that the beta-oxidation of DCAs in rat liver, therefore, must be carried out exclusively in peroxisomes.

Acyl-CoA Dehydrogenases↗
PubMed1998

Massive production of farnesol-derived dicarboxylic acids in mice treated with the squalene synthase inhibitor zaragozic acid A.

The zaragozic acids are potent inhibitors of squalene synthase. In vivo studies in mice confirmed our earlier observations that inhibition of squalene synthase by zaragozic acid A was accompanied by an increase in the incorporation of label from [3H]mevalonate into farnesyl-diphosphate (FPP)-derived isoprenoic acids (J. D. Bergstrom et al., 1993, Proc. Natl. Acad. Sci. USA 90, 80-84). Farnesyl-diphosphate-derived metabolites appear transiently in the liver. We were unable to detect any farnesol formation in the zaragozic acid-treated animals which indicates that FPP is readily converted to farnesoic acid and dicarboxylic acids in the liver. These metabolites were found to be produced only in the liver and not in the kidney. trans-3,7-Dimethyl-2-octaen-1,8-dioic acid and 3, 7-dimethyloctan-1,8-dioic acid were identified as the major end products of farnesyl-diphosphate metabolism in the urine of mice treated with zaragozic acid A. Quantitative analysis of these FPP-derived dicarboxylic acids by gas-liquid chromatography revealed that approximately 11 mg of total dicarboxylic acids is excreted per day into the urine of a mouse after 3 days of treatment with zaragozic acid A.

Animals↗
PubMed2004

Determination of the carbon deficiency in the flame ionization detector response of long-chain fatty acid methyl esters and dicarboxylic acid dimethyl esters.

Carbon deficiencies (CDs) of long-chain fatty acid methyl esters (FAMEs) and dicarboxylic acid dimethyl esters (DDMEs), which lead to decreased response in a flame ionization detection (FID) system, were determined by using full responding hydrocarbons (heptadecane, eicosane and alpha-cholestane) as references. For saturated FAMEs ranging from C12 to C22 and for DDMEs ranging from C4 to C10, CDs between 1.3+/-0.12 and 1.7+/-0.36 per ester group were recorded. All values were significantly (P < 0.05) greater than 1. Generally, response factors for gas-chromatographic analysis using FID have been calculated on the theory that the CD of FAMEs is 1 per ester group. However, this theory could not be confirmed experimentally for short-chain FAMEs of less than 8 carbons as CDs of around 1.5 were reported for C4 and C6 FAMEs. The study presented here contributes an approach to this problem by confirming the validity of response factors calculated from a CD of 1.5 per ester group as well as for long-chain FAMEs and DDMEs.

Carbon↗
PubMed2006

Immobilized cell reactors in mineralization of dicarboxylic acid solid waste.

Dicarboxylic acid solid waste containing phthalic acid, malic acid, quinone, saturated and unsaturated dicarboxylic esters etc., are discharged in huge quantities during the crackdown of benzene over the catalyst vanadium at temperatures greater than 500 degrees C in a dicarboxylic acid manufacturing industry. Concern over the biological effects of these compounds underlines the necessity to treat this solid waste. The role of yeast Saccharomyces cerevisiae and anaerobic mixed bacterial cultures immobilized in activated carbon, in sequential two stage anoxic reactors, were investigated for the degradation of dicarboxylic acid solid waste (DASW). In the first stage, DASW was dissolved in water to yield a concentration of 0.5% w/v and was treated in yeast Saccharomyces cerevisiae immobilized reactor at an optimum residence time of 24 h. The yeast fermented samples were further treated in an upflow anaerobic reactor containing mixed culture immobilized in activated carbon at an Hydraulic Retention Time (HRT) of 0.2076 days at an hydraulic flow rate of 14.6x10(-3 )m(3)/day and Chemical Oxygen Demand (COD) loading rate of 4.3 kg/m(3)/day. The intermediates that were formed during the yeast fermentation and the anaerobic degradation of DASW were characterized by HPLC, proton NMR, C(13) NMR and mass spectrometry.

Adsorption↗
PubMed1992

Formation and degradation of dicarboxylic acids in relation to alterations in fatty acid oxidation in rats.

Dicarboxylic acids are excreted in urine when fatty acid oxidation is increased (ketosis) or inhibited (defects in beta-oxidation) and in Reye's syndrome. omega-Hydroxylation and omega-oxidation of C6-C12 fatty acids were measured by mass spectrometry in rat liver microsomes and homogenates, and beta-oxidation of the dicarboxylic acids in liver homogenates and isolated mitochondria and peroxisomes. Medium-chain fatty acids formed large amounts of medium-chain dicarboxylic acids, which were easily beta-oxidized both in vitro and in vivo, in contrast to the long-chain C16-dicarboxylic acid, which was toxic to starved rats. Increment of fatty acid oxidation in rats by starvation or diabetes increased C6:C10 dicarboxylic acid ratio in rats fed medium-chain triacylglycerols, and increased short-chain dicarboxylic acid excretion in urine in rats fed medium-chain dicarboxylic acids. Valproate, which inhibits fatty acid oxidation and may induce Reye like syndromes, caused the pattern of C6-C10-dicarboxylic aciduria seen in beta-oxidation defects, but only in starved rats. It is suggested, that the origin of urinary short-chain dicarboxylic acids is omega-oxidized medium-chain fatty acids, which after peroxisomal beta-oxidation accumulate as C6-C8-dicarboxylic acids. C10-C12-dicarboxylic acids were also metabolized in the mitochondria, but did not accumulate as C6-C8-dicarboxylic acids, indicating that beta-oxidation was completed beyond the level of adipyl CoA.

Animals↗
PubMed2003

Reaction of aspartate aminotransferase with C5-dicarboxylic acids: comparison with the reaction with C4-dicarboxylic acids.

The reaction of Escherichia coli aspartate aminotransferase (AspAT) with glutamate and other C5-dicarboxylates was analyzed in order to compare its mechanism of action toward C5 substrates with that toward C4 substrates, which had been extensively characterized. The association of the amino-group protonated and unprotonated forms of glutamate (SH(+) and S, respectively) with the Schiff-base protonated and unprotonated forms of the enzyme (E(L)H(+) and E(L), respectively) yields at least three forms of the Michaelis complex, whereas in the case of aspartate, only two species of this complex exist, E(L).SH(+) and E(L)H(+).S. The reaction of AspAT with 2-methylglutamate can be explained only when we consider all the protonation states of the Michaelis complex. Based on the previous crystallographic studies [Miyahara et al. (1994) J. Biochem. 116, 1001-1012], we consider that glutamate binds to the open form of AspAT and takes an extended conformation in the Michaelis complex, with the alpha-amino group of glutamate oriented in the opposite direction to the Schiff base. This is in contrast to the Michaelis complex of aspartate, in which a strong interaction of the alpha-amino group of aspartate and the Schiff base excludes the presence of the species E(L)H(+).SH(+). It is concluded that AspAT recognizes the two types of dicarboxylates with different chain lengths by changing the gross conformation of the enzyme protein.

Aspartate Aminotransferases↗
PubMed1991

Characterization of the binding sites for dicarboxylic acids on bovine serum albumin.

Dicarboxylic acids are prominent features of several diseases, including Reye's syndrome and inborn errors of mitochondrial and peroxisomal fatty acid oxidation. Moreover, dicarboxylic acids are potentially toxic to cellular processes. Previous studies [Tonsgard, Mendelson & Meredith (1988) J. Clin. Invest. 82, 1567-1573] demonstrated that long-chain dicarboxylic acids have a single high-affinity binding site and between one and three lower-affinity sites on albumin. Medium-chain-length dicarboxylic acids have a single low-affinity site. We further characterized dicarboxylic acid binding to albumin in order to understand the potential effects of drugs and other ligands on dicarboxylic acid binding and toxicity. Progesterone and oleate competitively inhibit octadecanedioic acid binding to the single high-affinity site. Octanoate inhibits binding to the low-affinity sites. Dansylated probes for subdomain 2AB inhibit dodecanedioic acid binding whereas probes for subdomain 3AB do not. In contrast, low concentrations of octadecanedioic acid inhibit the binding of dansylated probes to subdomain 3AB and 2AB. L-Tryptophan, which binds in subdomain 3AB, inhibits hexadecanedioic acid binding but has no effect on dodecanedioic acid. Bilirubin and acetylsalicylic acid, which bind in subdomain 2AB, inhibit the binding of medium-chain and long-chain dicarboxylic acids. Our results suggest that long-chain dicarboxylic acids bind in subdomains 2C, 3AB and 2AB. The single low-affinity binding site for medium-chain dicarboxylic acids is in subdomain 2AB. These studies suggest that dicarboxylic acids are likely to be unbound in disease states and may be potentially toxic.

Acylation↗
PubMed1990

Transport of malic acid and other dicarboxylic acids in the yeast Hansenula anomala.

DL-Malic acid-grown cells of the yeast Hansenula anomala formed a saturable transport system that mediated accumulative transport of L-malic acid with the following kinetic parameters at pH 5.0: Vmax, 0.20 nmol.s-1.mg (dry weight)-1; Km, 0.076 mM L-malate. Uptake of malic acid was accompanied by proton disappearance from the external medium with rates that followed Michaelis-Menten kinetics as a function of malic acid concentration. Fumaric acid, alpha-ketoglutaric acid, oxaloacetic acid, D-malic acid, and L-malic acid were competitive inhibitors of succinic acid transport, and all induced proton movements that followed Michaelis-Menten kinetics, suggesting that all of these dicarboxylates used the same transport system. Maleic acid, malonic acid, oxalic acid, and L-(+)-tartaric acid, as well as other Krebs cycle acids such as citric and isocitric acids, were not accepted by the malate transport system. Km measurements as a function of pH suggested that the anionic forms of the acids were transported by an accumulative dicarboxylate proton symporter. The accumulation ratio at pH 5.0 was about 40. The malate system was inducible and was subject to glucose repression. Undissociated succinic acid entered the cells slowly by simple diffusion. The permeability of the cells by undissociated acid increased with pH, with the diffusion constant increasing 100-fold between pH 3.0 and 6.0.

Biological Transport, Active↗
PubMed1990

Fermentative degradation of dipicolinic acid (pyridine-2,6-dicarboxylic acid) by a defined coculture of strictly anaerobic bacteria.

Degradation of dipicolinic acid (pyridine-2,6-dicarboxylic acid) under strictly anaerobic conditions was studied in enrichment cultures from marine and freshwater sediments. In all cases, dipicolinic acid was completely degraded. From an enrichment culture from a marine sediment, a defined coculture of two bacteria was isolated. The dipicolinic acid-fermenting bacterium was a Gram-negative, non-sporeforming strictly anaerobic short rod which utilized dipicolinic acid as sole source of carbon, energy, and nitrogen, and fermented it to acetate, propionate, ammonia, and 2CO2. No other substrate was fermented. This bacterium could be cultivated only in coculture with another Gram-negative, non-sporeforming rod from the same enrichment culture which oxidized acetate to CO2 with fumarate, malate, or elemental sulfur as electron acceptor, similar to Desulfuromonas acetoxidans. Since this metabolic activity is not important in substrate degradation by the coculture, the basis of the dependence of the dipicolinic acid-degrading bacterium on the sulfur reducer may be sought in the assimilatory metabolism.

Anaerobiosis↗
PubMed2003

Vanadium(IV/V) speciation of pyridine-2,6-dicarboxylic acid and 4-hydroxy-pyridine-2,6-dicarboxylic acid complexes: potentiometry, EPR spectroscopy and comparison across oxidation states.

Evaluation of stability of vanadium(IV) and (V) complexes under similar conditions is critical for the interpretation and assessment of bioactivity of various vanadium species. Detailed understanding of the chemical properties of these complexes is necessary to explain differences observed their activity in biological systems. These studies are carried out to link the chemistry of both vanadium(IV) and (V) complexes of two ligands, 2,6-pyridinedicarboxylic acid (dipicolinic acid, H(2)dipic) and 4-hydroxy-2,6-pyridinedicarboxylic acid (H(2)dipic-OH). Solution speciation of the two 2,6-pyridinedicarboxylic acids with vanadium(IV) and vanadium(V) ions was determined by pH-potentiometry at I=0.2 M (KCl) ionic strength and at T=298 K. The stability and the metal affinities of the ligands were compared. Vanadium(V) complexes were found to form only tridentate coordinated 1:1 complexes, while vanadium(IV) formed complexes with both 1:1 and 1:2 stoichiometries. The formation constant reflects hindered coordination of a second ligand molecule, presumably because of the relatively small size of the metal ion. The most probable binding mode of the complexes was further explored using ambient and low temperature EPR spectroscopy for vanadium(IV) and 51V NMR spectroscopy for vanadium(V) systems. Upon complex formation the pyridinol-OH in position 4 deprotonates with pK approximately 3.7-4.1, which is approximately 6 orders of magnitude lower than that of the free ligand. The deprotonation enhances the ligand metal ion affinity compared to the parent ligand dipicolinic acid. In the light of the speciation and stability data of the metal complexes, the efficiency of the two ligands in transporting the metal ion in the two different oxidation states are assessed and discussed.

Electron Spin Resonance Spectroscopy↗
PubMed1999

New peptidic cysteine protease inhibitors derived from the electrophilic alpha-amino acid aziridine-2,3-dicarboxylic acid.

Three different types of peptides containing aziridine-2, 3-dicarboxylic acid (Azi) as an electrophilic alpha-amino acid at different positions within the peptide chain (type I, N-acylated aziridines with Azi as C-terminal amino acid; type II, N-unsubstituted aziridines with Azi as N-terminal amino acid; type III, N-acylated bispeptidyl derivatives of Azi) have been synthesized and tested as inhibitors of the cysteine proteases papain, cathepsins B, L, and H, and calpains I and II, as well as against several serine proteases, one aspartate, and one metalloprotease. All aziridinyl peptides are specific cysteine protease inhibitors. Papain and cathepsins B and L are inhibited irreversibly, whereas cathepsin H and calpains are inhibited in a non-time-dependent manner. Some compounds turned out to be substrates for serine proteases and for the metalloprotease thermolysin. Remarkable differences can be observed between the three different types of inhibitors concerning stereospecificity, pH dependency of inhibition, selectivity between different cysteine proteases, and the importance of a free carboxylic acid function at the aziridine ring for inhibition. Above all type II inhibitors, aza analogues of the well-known epoxysuccinyl peptides, are potent cysteine protease inhibitors. With the exception of BOC-Leu-Gly-(S, S+R,R)-Azi-(OEt)2 (28a+b), a highly selective and potent cathepsin L inhibitor, N-acylated aziridines of type I are weaker inhibitors than type II or type III compounds. The observed results can be explained by different binding modes of the three types of inhibitors with respect to their orientation in the S- and S'-binding sites of the enzymes. Furthermore, the presence of a protonated aziridine N modifies the binding mode of type II inhibitors.

Aziridines↗
PubMed1991

Inhibition of high affinity L-glutamic acid uptake into rat cortical synaptosomes by the conformationally restricted analogue of glutamic acid, cis-1-aminocyclobutane-1,3-dicarboxylic acid.

The action of two cyclobutane derivatives of L-glutamic acid on the high affinity uptake of L-glutamic acid was investigated using a preparation of synaptosomes from rat cerebral cortex. cis-1-Aminocyclobutane-1,3-dicarboxylic acid (also known as trans-2,4-methanoglutamic acid) potently inhibited L-glutamic acid uptake (IC50 30 microM), whereas trans-1-aminocyclobutane-1,3-dicarboxylic acid (also known as cis-2,4-methanoglutamic acid), a potent N-methyl-D-aspartate (NMDA) agonist, was inactive. Analysis of the kinetics of L-glutamic acid uptake in the presence and absence of cis-1-aminocyclobutane-1,3-dicarboxylic acid (CACB) suggests that it may act as a competitive inhibitor (Ki 8 microM). CACB may be substrate for the L-glutamic acid high-affinity uptake carrier since preincubation of CACB with the synaptosomal preparation increased its potency in inhibiting L-glutamic acid uptake. The conformationally restricted structure of CACB may be indicative of the conformations of L-glutamic acid that interact with the high affinity uptake carrier.

Amino Acids, Dicarboxylic↗
PubMed2003

Adducts of hexamethylenetetramine with ferrocenecarboxylic acid and ferrocene-1,1'-dicarboxylic acid: multiple disorder in space groups Fmm2 and Cmcm.

Hexamethylenetetramine, C(6)H(12)N(4), and ferrocenecarboxylic acid, C(11)H(10)FeO(2), form a 1:2 adduct, (I), which is a salt, viz. hexamethylenetetraminium(2+) bis(ferrocenecarboxylate), (C(6)H(14)N(4))[Fe(C(5)H(5))(C(6)H(4)O(2))](2). The dication in (I) is disordered with two orientations at a site of mm2 symmetry in space group Fmm2, while the anion lies across a mirror plane with its unsubstituted cyclopentadienyl ring disordered over two sets of sites. With ferrocene-1,1'-dicarboxylic acid, C(12)H(10)FeO(4), hexamethylenetetramine forms a 1:1 adduct, (II), in which both components are neutral, viz. hexamethylenetetramine-ferrocene-1,1'-dicarboxylic acid (1/1), [Fe(C(6)H(5)O(2))(2)].C(6)H(12)N(4). The amine component in (II) is disordered with two orientations at a site of mm2 symmetry in space group Cmcm, while the acid component is disordered with two orientations at a site of 2/m symmetry. The components in (I) are linked into a finite three-ion aggregate by a single N-H.O hydrogen bond, while the components of (II) are linked into continuous chains by a single O-H.N hydrogen bond.

Journal Article↗