Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Pipecolic 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 271 records · Page 15Linked to original sources
PubMedDate not supplied

Myopathy in an infant with a fatal peroxisomal disorder.

An infant with neonatal adrenoleukodystrophy experienced extreme hypotonia and virtually continuous convulsions at four months of age and died. Light and electron microscopic examination revealed evidence of myopathy and the presence of mitochondrial inclusions. Concentrations of very long-chain fatty acids were elevated in blood and fibroblasts and the oxidation of 14C-labeled fatty acids was defective. Urinary pipecolic acid content was increased. Activity of the peroxisomal dihydroxyacetone phosphate acyltransferase, which catalyzes the first step in plasmalogen synthesis, was decreased.

Acyltransferases↗
PubMed1991

Postnatal development and isolation of peroxisomes from brain.

We analyzed the postnatal peroxisome development in rat brain by measuring the enzyme activities of catalase and acyl-CoA oxidase and beta-oxidation of [1-14C]lignoceric acid. These enzyme activities were higher between 10 and 16 days of postnatal life and then decreased. We developed and compared two different methods for isolation of enriched peroxisomes from 10-day-old rat brain by using a combination of differential and density gradient centrifugation techniques. Peroxisomes in Percoll (self-generating gradient) banded at a density of 1.036 +/- 0.012 g/ml and in Nycodenz continuous gradient at 1.125 +/- 0.014 g/ml. Acyl-CoA oxidase, D-amino acid oxidase, L-pipecolic acid oxidase, and dihydroxyacetone phosphate acyltransferase activities and activities for the oxidation of very long chain fatty acid (lignoceric acid) were almost exclusively associated with catalase activity (a marker enzyme for peroxisomes) in the gradient. The postnatal increase in peroxisomal activity with the onset of myelination and the presence of enzyme for the biosynthesis of plasmalogens and oxidation of very long chain fatty acid (both predominant constituents of myelin) suggest that brain peroxisomes may play an important role in the assembly and turnover of myelin.

Animals↗
PubMed1989

Peroxisomal bifunctional enzyme deficiency.

Peroxisomal function was evaluated in a male infant with clinical features of neonatal adrenoleukodystrophy. Very long chain fatty acid levels were elevated in both plasma and fibroblasts, and beta-oxidation of very long chain fatty acids in cultured fibroblasts was significantly impaired. Although the level of the bile acid intermediate trihydroxycoprostanoic acid was slightly elevated in plasma, phytanic acid and L-pipecolic acid levels were normal, as was plasmalogen synthesis in cultured fibroblasts. The latter three parameters distinguish this case from classical neonatal adrenoleukodystrophy. In addition, electron microscopy and catalase subcellular distribution studies revealed that, in contrast to neonatal adrenoleukodystrophy, peroxisomes were present in the patient's tissues. Immunoblot studies of peroxisomal beta-oxidation enzymes revealed that the bifunctional enzyme (enoyl-CoA hydratase/3-hydroxyacyl-CoA dehydrogenase) was deficient in postmortem liver samples, whereas acyl-CoA oxidase and the mature form of beta-ketothiolase were present. Density gradient centrifugation of fibroblast homogenates confirmed that intact peroxisomes were present. Immunoblots of fibroblasts peroxisomal fractions showed that they contained acyl-CoA oxidase and beta-ketothiolase, but bifunctional enzyme was not detected. Northern analysis, however, revealed that mRNA coding for the bifunctional enzyme was present in the patient's fibroblasts. These results indicate that the primary biochemical defect in this patient is a deficiency of peroxisomal bifunctional enzyme. It is of interest that the phenotype of this patient resembled neonatal adrenoleukodystrophy and would not have been distinguished from this disorder by clinical study alone.

3-Hydroxyacyl CoA Dehydrogenases↗
PubMed1993

Studies on RA derivatives. V. Synthesis and antitumor activity of Ala2-modified RA-VII derivatives.

A number of RA-VII derivatives having various amino acids including proline (6), pipecolic acid (11), norvaline (12), ornithine (14), aspartic acid (15) and methionine (20) in place of Ala2 have been synthesized from RA-X methyl ester (3) and evaluated for cytotoxicity to P388 leukemia and KB cells in vitro. Comparison of the cytotoxicity of these compounds suggests that the polarity and the length of the 2nd amino acid residue affect the activity. An NMR study revealed that, in solution, 6 and 11 are locked in one conformational state, corresponding to conformer A of RA-VII.

Animals↗
PubMed2002

Glutaric aciduria type III: a distinctive non-disease?

Glutaric aciduria type III is a rare metabolic abnormality leading to persistent isolated glutaric acid excretion. We report the clinical and biochemical phenotypes of three affected children. The first patient is a boy with dysmorphic features and a chromosomal deletion (monosomy 6q26-qter) in whom a persistent glutaric aciduria (500 mmol/mol creatinine, normal <10) was detected during a routine metabolic investigation. The second boy suffered from acute gastroenteritis and hyperthyroidism, when an excessively high urinary glutaric acid excretion was identified (1460 mmol/mol creatinine). The third patient is a girl with constantly elevated glutaric acid in her urine (290 mmol/mol creatinine) but no symptoms of significant disease. In all our patients, glutaric aciduria type I (glutaryl-CoA dehydrogenase deficiency), glutaric aciduria type II (multiple acyl-CoA dehydrogenation defect), and secondary forms of glutaric aciduria (for example due to intestinal infections or mitochondrial dysfunction) could be excluded. Loading with the precursor amino acid lysine in all patients as well as with pipecolic acid in the third case led to an increase in urinary glutaric acid excretion, proving the endogenous origin of glutarate. Glutaric aciduria type III (a defect reported to be caused by peroxisomal glutaryl-CoA oxidase deficiency) is our presumptive diagnosis. However, peroxisomal glutaryl-CoA oxidase is not well characterized and no reliable approach for the direct determination of this enzyme is available to us. To our knowledge, in the English language literature only a single patient with glutaric aciduria type III has been described. Our cases reported here confirm the earlier assumption that glutaric aciduria type III is not related to a distinctive phenotype. Glutaric aciduria type III appears to be a rare metabolic abnormality, presumably of peroxisomal metabolism. However, its pathophysiological impact still needs further investigation.

Amino Acid Metabolism, Inborn Errors↗
PubMed1997

L-alpha-aminoadipate inhibits kynurenate synthesis in rat brain hippocampus and tissue culture.

Intracerebral administration of L-alpha-aminoadipic acid (L-AAA) at 500 mg/kg body weight to rats caused a complex behavioral change with sporadic wet-dog shakes. Animals developed severe limbic seizures between 1 and 6 h after L-AAA injection, characterized by generalized convulsions. Twenty days after L-AAA injection kynurenine aminotransferase (KAT) activity measured in hippocampal brain tissue slices prepared with a McIlwain chopper at 30 microns showed a significant 43% decrease. Subcutaneous injection of kynurenine at 500 mg/kg showed a 63% increase in KAT activity twenty days later. This increase was offset by a concomitant administration of 500 mg/kg L-AAA stereotaxically on day one. In astrocyte culture kynurenic acid synthesis is inhibited by L-AAA and L-pipecolic acid. The possible involvement of kynurenic acid in the modulation of neuronal degeneration is discussed.

2-Aminoadipic Acid↗
PubMed1977

Nitramino acids. Synthesis and biological evaluation of 1-nitroproline, 1-nitropipecolic acid, and N-nitrosarcosine.

The N-nitro derivatives of secondary alpha-amino acids, viz., 1-nitroproline (1a) (L and D), 1-nitro-DL-pipecolic acid (2a), and N-nitrosarcosine (3a), were prepared by the oxidation of the corresponding nitrosamino acids with peroxytrifluoroacetic acid. These nitramino acids (1a-3a) were not active against Escherichia coli, Candida albicans, Pseudomonas aeruginosa, or Mycobacterium smegmatis, and 1a and 2a did not show mutagenic activity in a Salmonella typhimurium TA-100 system, with or without added rat liver 9000g supernatant fraction. The marginal mutagenicity of 3a in this system suggests that additional work should be done to assess its carcinogenic-mutagenic potential.

Animals↗
PubMed1996

Nonprotein amino acids from seeds of Cycas circinalis and Phaseolus vulgaris.

Our chemical studies on Cycas circinalis seeds from Guam has provided two new nonprotein amino acids, N-(3'-one-5'-methyl)-hexylalanine and leucine betaine. N-methylisoleucine, previously reported as a component of naturally occurring peptides, has been isolated as a free amino acid from the seeds of Phaseolus vulgaris (pinto bean), together with S-methylcysteine, pipecolic acid and a dipeptide, gamma-glutamyl-leucine.

Alanine↗
PubMed2003

Discrimination between arabica and robusta coffee species on the basis of their amino acid enantiomers.

This work reports the results for the composition of robusta and arabica coffee species in terms of their amino acid enantiomers in the green and roasted states. The analyses were conducted for the free amino acids, as well as for the amino acids obtained after acid hydrolysis. The amino acids were extracted/hydrolyzed and isolated by SPE on strong cation exchange columns, derivatized to their N-ethoxycarbonylheptafluorobutyl esters, and analyzed by gas chromatography/FID on a Chirasil l-Val column. Multivariate analyses applied to the results showed that the free amino acids can be used as a tool for discrimination between coffee species, with a special reference to l-glutamic acid, l-tryptophan, and pipecolic acid. There is also some evidence that these compounds can be used for discrimination between green coffees subjected to different postharvest processes. It is also shown that the amino acid levels observed after acid hydrolysis can be used for the same purposes, although displaying less discriminatory power.

Amino Acids↗
PubMed2006

Design and synthesis of diversely substituted azacyclic inhibitors of endothelin converting enzyme.

A series of azacyclic phosphonic acids were synthesized from L-pyroglutamic acid, 6-oxo-L-pipecolic acid, and their enantiomers. The objective was to study the effect of constraining acyclic inhibitors of endothelin converting enzyme on inhibitory activity. Potential pharmacophoric tethers were introduced by stereocontrolled reactions to give highly substituted pyrrolidine- and piperidine-alpha-phosphonic acids. Weak inhibitory activity was observed for one diastereomer in each series having the same relative orientation of substituents.

Aspartic Acid Endopeptidases↗
PubMed2004

Transport of pharmacologically active proline derivatives by the human proton-coupled amino acid transporter hPAT1.

Several proline derivatives such as L-azetidine-2-carboxylic acid, cis-4-hydroxy-L-proline, and 3,4-dehydro-DL-proline prevent procollagen from folding into a stable triple-helical conformation, thereby reducing excessive deposition of collagen in fibrotic processes and the growth of tumors. This study was performed to investigate whether the recently discovered human proton-coupled amino acid transporter 1 (hPAT1) is capable of transporting such pharmacologically relevant proline derivatives and also GABA analogs. Uptake of L-[3H]proline and [3H]glycine in Caco-2 cells was Na+-independent but strongly H+-dependent. The L-proline uptake was saturable and mediated by a single transport system (hPAT1) with an affinity constant of 2.0 +/- 0.2 mM. The uptake of L-[3H]proline was inhibited by D-proline, trans-4-hydroxy-L-proline, cis-4-hydroxy-L-proline, cis-4-hydroxy-D-proline, 3,4-dehydro-DL-proline, L-azetidine-2-carboxylic acid, 3-amino-1-propanesulfonic acid, D- and L-pipecolic acid, l-thiaproline, and many others. Apical uptake and transepithelial flux of L-[3H]proline across Caco-2 cell monolayers were strongly inhibited by proline derivatives in proportions corresponding to their respective affinity constants at hPAT1. The basolateral to apical flux of L-[3H]proline was only 8% of that in the opposite direction. Apical uptake of unlabeled L-proline, cis-4-hydroxy-L-proline, and L-azetidine-2-carboxylic acid was stimulated by an inside directed H+ gradient 2- to 3-fold. Total apical to basolateral flux of proline derivatives was moderately correlated with their inhibitory potency for L-[3H]proline uptake and flux inhibition. We conclude that 1) the substrate specificity of hPAT1 is very much broader than so far reported and 2) the system accepts therapeutically relevant proline and GABA derivatives. hPAT1 is a promising candidate for new ways of oral drug delivery.

Amino Acid Transport Systems↗
PubMed1985

Effects of L-lysine and its metabolites on pentylenetetrazol-induced seizures.

Lysine and its metabolic intermediates were studied for their effect on pentylenetetrazol (PTZ)-induced seizures in mice. L-Lysine at dosages above 2 mmol/kg given i.p. significantly increased seizure protection and seizure latency (the time required to develop seizures after PTZ injection) with a peak effect dose at 10 mmol/kg. A pretreatment time of 15 min was required to significantly prolong seizure latency with a peak effect time of 45 min. D-Lysine at 10 mmol/kg i.p. afforded some seizure protection and significantly prolonged seizure latency but has a peak effect time of 15 min. When administered intracerebroventricularly, both L-lysine and piperidine at 0.1 mmol/kg prolonged seizure latency significantly, and increased seizure protection slightly. L-Pipecolic acid at the same dose given through the same route, however, shortened seizure latency significantly. L-alpha-Aminoadipic acid, on the other hand, had no significant effect. Lysine metabolites that prolonged seizure latency also increased seizure protection and decreased seizure death, and one that shortened seizure latency had the opposite effect. The anticonvulsant activity of lysine and its metabolites was explained on the basis of their connection with the GABAergic transmission.

2-Aminoadipic Acid↗
PubMed1989

Zellweger syndrome, retinal involvement.

Progresses in biochemistry permit one to distinguish three biochemical forms of Zellweger Syndrome: 1) hyperpipecolic acidemia, 2) neonatal adrenoleukodystrophy, and 3) infantile Refsum's disease, which have similar clinical manifestations. A seven-month-old male patient with Zellweger Syndrome is presented. He had absence of peroxismes in the liver and elevated pipecolic acids and abnormal levels of bile acids in the blood. The child had a typical neurologic clinical manifestation with hepatomegaly. The ophthalmoscopy revealed grey disks and retinitis pigmentosa with extinguished ERG and law and delayed VEP. The importance of the constant retinal involvement in Zellweger Syndrome is discussed.

Bile Acids and Salts↗
PubMed1994

Stimulation of synthesis and release of swainosonine from transformed roots of Swainsona galegifolia.

Transformed root cultures of Swainsona galegifolia were established for swainsonine production. Stimulation of production of swainsonine and its release into the culture medium was achieved using copper sulphate, reduction of medium pH and supply of swainsonine precursors. The yield of control cultures (0.3 g of roots grown in 15 ml medium for 30 days) was 79 micrograms swainsonine with only a trace of swainsonine in the medium. After treatment with 1 mM copper sulphate for two days before harvest on day 30, 155 micrograms of swainsonine was produced, of which 14.3 micrograms was in the medium. Reduction of medium pH from 5.7 to 2.7 for one day before harvest resulted in 159 micrograms of swainsonine (47 micrograms in the medium). Supplementation with 2 mM malonic acid for 12 days before harvest resulted in 187 micrograms total swainsonine (34 micrograms in the medium), while 2 mM pipecolic acid for six days before harvest gave the highest swainsonine yield (220 micrograms total, 43 micrograms in the medium). The increased yields were achieved through small increases in biomass, as well as increases in the level of swainsonine synthesis.

Copper↗
PubMed1995

Effect of amino acids on rapamycin biosynthesis by Streptomyces hygroscopicus.

In a chemically defined medium containing aspartate, arginie and histidine to support good growth, addition of L-lysine stimulated rapamycin production by 150%. This was probably due to its conversion to pipecolic acid, a rapamycin precursor. Phenylalanine and methionine interfered in rapamycin production by unknown mechanisms.

Amino Acids↗
PubMedDate not supplied

[Zellweger's syndrome (cerebro-hepato-renal syndrome)--its clinical picture, morphology and biochemical diagnosis].

The cerebro-hepato-renal (Zellweger) syndrome is characterised by dysmorphic features, severe muscular hypotonia, hepatic dysfunction and early death in infancy. Recently it has been shown that the disease is an inborn error of metabolism with an unusual variety of metabolic disturbances affecting pipecolic acid, bile acids, plasmalogens and very long chain fatty acids. Ultrastructural and biochemical findings confirming the diagnosis are illustrated. The syndrome is inherited as an autosomal recessive trait, prenatal diagnosis has become possible.

Abnormalities, Multiple↗
PubMed1989

Proline and proline derivatives as anticonvulsants.

1. The anticonvulsant properties of L-proline, of proline derivatives (trans-4-hydroxy-L-proline, cis-4-hydroxy-D-proline, 3,4-dehydro-D,L-proline) and of D- and L-pipecolic acid were studied alone and in combination with vigabatrin (R/S-4-aminohex-5-enoic acid). 3-Mercaptopropionic acid and pentylenetetrazol-induced convulsions in mice were used as animal models of epilepsy. 2. Proline and proline derivatives are weak anticonvulsants if given alone in doses up to 10 mmol/kg, however, they are capable of potentiating the anticonvulsant effects of vigabatrin, in a manner similar to that reported previously for glycine, and some glycine derivatives. Among the compounds tested, trans-4-hydroxy-L-proline was the most potent anticonvulsant in combination with the indirect GABA agonist vigabatrin. 3. A potential explanation for the synergistic anticonvulsant effect of the combination of the GABA agonist and proline is the presumed role of proline as inhibitory neurotransmitter, and/or its glutamate antagonistic effects. 4. The current study points out the lack of basic knowledge on the neurochemistry and pharmacology of proline and hydroxyproline.

3-Mercaptopropionic Acid↗