The water-soluble B-vitamins: Alloxazine-adenine-dinucleotide, adenylic acid, nicotinamide and pimelic acid in the nutrition of the rat.
Explore the source record for details and available documents.
SEARCH · PubMed Health
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Explore the source record for details and available documents.
The kinetics of abdomen, haemolymph and thoracic-muscle steroid and phospholipid concentrations have been determined in adult worker-bees kept for 0 to 12 hrs starving in darkness, either grouped by 8 (controls) or strictly isolated, or isolated in presence of a piece of cotton impregnated with 1 microgram azelaic acid and 1 microgram pimelic acid, the so-called "survivones" which restore the lifespan of isolated bees. The dynamics of both steroids and phospholipids strongly deviates in isolated bees relatively to controls. The introduction of survivones completely restored the variations of haemolymph steroids of haemolymph and thorax phospholipids of isolated bees to exactly similar features as in controls. The action of the lipoic hormones "survivones" thus involves the participation of lipid metabolism.
This paper deals with the polarized IR spectra of the hydrogen bond in pimelic acid crystals and their quantitative interpretation. The spectra were measured for the vO-H and vO-D band frequency regions, at temperatures of 298 and 77 K, for the 'alpha' crystalline form of pimelic acid. Two kinds of transmission spectra were obtained, for the beam perpendicular to the two different crystalline faces: 'ac' and 'ab'. The spectra of the hydrogen and the deuterium bonded systems were quantitatively reproduced, with sufficient accuracy, on the basis of the 'strong-coupling' model, assuming the (COOH)2 cycles to be the structural units responsible for the basic spectral properties. It was found that the spectra could be reproduced only, when assuming spectral activity in the IR of the totally symmetric proton stretching vibrations in centrosymmetric cyclic dimers of hydrogen bonds. The polarization effects in the crystal spectra were interpreted as directly connected with the hydrogen bond orientation in the crystal. However, in the pimelic acid crystalline spectra there were not observed another polarization effects characteristic for another carboxylic acid crystals, depending on differentiation of the long- and of the short-wave branch properties of each of the vO-H and vO-D bands. The temperature variation only affect the intensity ratio between the lower- and the higher-frequency branches of the vO-H and vO-D bands. These spectral effects were ascribed to less strained hydrogen bond structures in the pimelic acid lattices of the alpha' crystalline form and a relatively low concentration of defects in the lattices.
The biosynthesis of biotin-vitamers from C18 fatty acids in the resting cell reaction system of yeasts was investigated. The formation of pimelic acid (a biotin precursor) and biotin-vitamers (a mixture of 7-keto-8-aminopelargonic acid and dethiobiotin) from linolenic, linoleic, and oleic acids was observed in certain yeasts belonging to the genera Cryptococcus, Candida, Rhodotorula, and Trichosporon. Metabolites from linolenic acid were analyzed by gas-liquid chromatography and mass spectrometry. Linoleic, oleic, stearic, heptadecanoic, palmitic, pentadecanoic, and pimelic acids were identified as metabolites of linolenic acid. The existence of a route to pimelic acid from linolenic acid in a strain of Rhodotorula rubra AKU 4836 was also indicated.
Azelaic and pimelic acids are excreted in elevated amounts in urine in disorders of mitochondrial beta-oxidation and disorders of peroxisomal beta-oxidation, for which they are of significant diagnostic value. We have detected the presence of azelaic, pimelic and even-chain-length dicarboxylic acids (adipic, suberic and sebacic acids) arising artefactually as a result of storage of small sample volumes in plastic containers. Storage of samples for organic acid analysis in glass containers is recommended.
The complexes of L-arginine and DL-lysine with pimelic acid are made up of singly positively charged zwitterionic amino acid cations and doubly negatively charged pimelate ions in a 2:1 ratio. In both structures, the amino acid molecules form twofold symmetric or centrosymmetric pairs that are stabilized by hydrogen bonds involving alpha-amino and alpha-carboxylate groups. In the L-arginine complex, these pairs form columns along the shortest cell dimension, stabilized by intermolecular hydrogen bonds involving alpha-amino and alpha-carboxylate groups. The columns are connected by hydrogen bonds and water bridges to give rise to an amino acid layer. Adjacent layers are then connected by pimelate ions. Unlike molecular ions aggregate into alternating distinct layers in the DL-lysine complex. In the amino acid layer, hydrogen-bonded lysinium dimers related by a glide plane are connected by hydrogen bonds involving alpha-amino and alpha-carboxylate groups into head-to-tail sequences. Interestingly, the aggregation pattern observed in L-arginine hemipimelate monohydrate is very similar to those in DL-arginine formate dihydrate, DL-arginine acetate monohydrate and L-arginine hemiglutarate monohydrate. Similarly, the aggregation of amino acid molecules is very similar in DL-lysine hemipimelate 0.53-hydrate, DL-lysine formate and DL-lysine hydrochloride. The complexes thus demonstrate how, in related structures, the effects of a change in composition, and sometimes even those of reversal in chirality, can be accommodated by minor adjustments in essentially the same aggregation pattern. It also transpires that the conformation of the argininium ion is the same in the four argininium complexes; the same is true about the conformation of the lysinium ion in the three lysinium complexes. This result indicates a relation between, and mutual dependence of, conformation and aggregation.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The thermotropic phase diagram of 1:1 co-crystals of hexamethylenetetramine and pimelic acid (heptanedioic acid) is investigated. Three crystalline phases are identified at ambient pressure. Phase I is disordered, as revealed by diffuse rods in its diffraction pattern. When the temperature is lowered the diffuse streaks disappear in Phase II, but superstructure reflections emerge indicating an ordering process of the structure through a non-ferroic, or at least non-ferroelastic, phase transition. Phase II is mainly characterized by an unusual distribution of its reflection intensities. Phase III is reached through a ferroelastic phase transition that induces twinned domains. A model based on the stacking of an elementary layer is proposed with the aim of describing the structures in a unified framework. Depending on the value of the unique stacking parameter eta, each of the different structures observed can be reproduced by this model. Its validity is then tested by a series of simulations reproducing the main features of the diffraction patterns such as the diffuse scattering streaks, the occurrence of superstructure peaks at lower temperature and twinning.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
1. An unknown biotin vitamer was obtained in high yields in culture filtrates of Penicillium chrysogenum. 2. Production of this vitamer and desthiobiotin is controlled by the biotin concentration in the medium. 3. The unknown vitamer becomes labelled when the organism is grown in the presence of radioactive pimelic acid. 4. Chromatographic procedures were developed for the purification of the radioactive vitamer. 5. The vitamer is extremely stable in concentrated acid but gives rise to new vitamers under certain conditions. 6. The intermediate role of this vitamer in the synthesis of biotin is discussed.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
(1) 2,4-Dimethyladipic acid was first identified in normal human urine using gas chromatography-mass spectrometry. Urinary excretion of 2,4-dimethyladipic acid in 7 healthy adults ranged from 4.9 mumol to 14 mumol per 24 h. (2) Succinic acid, adipic acid, 3-methyladipic acid, 2,4-dimethyladipic acid, pimelic acid and azelaic acid were identified in the ultrafiltrate of the blood obtained from a chronic uremic patient using a hemodialyzer. (3) Levels of succinic acid, adipic acid, 3-methyladipic acid, 2,4-dimethyladipic acid, pimelic acid and azelaic acid in uremic serum were determined using a mass fragmentographic technique. Concentration of succinic acid in uremic serum was comparable to that in normal serum, whereas concentrations of adipic acid, 3-methyladipic acid, 2,4-dimethyladipic acid, pimelic acid and azelaic acid were highly elevated in uremic serum.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.