(n.) Any one of three isometric bases (C6H7N) related to pyridine, and obtained from bone oil, acrolein ammonia, and coal-tar naphtha, as colorless mobile liquids of strong odor; -- called also methyl pyridine.
Example Sentences:
(1) Inasmuch as we have previously demonstrated that the activation of cytotoxic M phi correlates with specific changes in ribosomal RNA (rRNA), we investigated whether picolinic acid could modify M phi RNA metabolism.
(2) beta-Phenethyl alcohol, fluoroacetic acid, and 2-picolinic acid inhibited anaerobic sporogenesis almost completely, butyrate biosynthesis by >87%, and acetate accumulation by 50 to 62%, showing a direct relationship between butyric type of fermentation and anaerobic sporulation.
(3) The effects of picolinic acid derivatives on blood pressure and norepinephrine levels in the heart were more remarkable in a stressed state than in a resting state.
(4) The binding rate constants of picolinate and nicotinate in the cationic form for the reduced enzyme were quite similar to each other, but the dissociation rate constant of picolinate is several times smaller than that of nicotinate.
(5) When co-injected into the nbM with a neurotoxic dose of kainic, ibotenic or quisqualic acid which produced a neurotoxic response comparable to that of QUIN, picolinic acid attenuated kainic acid-induced neurotoxicity, but not ibotenate or quisqualate neurotoxicity.
(6) Synthesis of new bis(1-methylpyridinium) compounds containing a 1,4-diacetylbenzene linkage between the pyridinium moieties from commercially available 2-, 3-, and 4-picoline precursors was accomplished via metallation, reaction of the picolyllithium with 1,4-dicyanobenzene, and subsequent quaternization of the resulting bispyridyl compounds.
(7) In picolinate experiments, the staining of nbM neurons by acetylcholinesterase (AChE) histochemistry was also examined.
(8) Neither quinolinic acid, a neurotoxin, nor its monocarboxylic analogue, picolinic acid, auto-oxidized over a wide pH range.
(9) Liver nicotinate phosphoribosyltransferase (EC 2.4.2.11) activity was also observed to decrease with moderate diet restriction and did not further change when the restriction was severe while picolinate carboxylase (EC 4.1.1.45) activity increased significantly only in severe diet restriction.
(10) The trans isomer also yields some picolinate as an identifiable product.
(11) The ability of prostaglandin E1 (PGE1) and cholera toxin to increase cyclic AMP levels is potentiated 6-fold when normal rat kidney (NRK) cells are treated with picolinic acid or histidinol, or grown in isoleucine-deficient medium.
(12) Twenty weanling pigs and fourteen 9-wk-old broiler chickens were used in three continuous-flow in vitro perfusion experiments using noneverted intestinal sacs to 1) determine differences in 65Zn absorption due to location within the intestinal tract, 2) evaluate 65Zn uptake from ZnCl2 and Zn-methionine (ZnMet) with or without added picolinic acid (PA) in pig intestinal sacs and 3) evaluate 65Zn uptake from ZnCl2 and ZnMet in chicken intestinal sacs.
(13) In a third experiment picolinic acid was introduced for 3 d into the diet of rats prelabeled with 65Zn.
(14) The effect of picolinic acid (pyridine-2-carboxylic acid) on the efflux of divalent metal ions from multilamellar liposomes was examined to determine the possible specificity and mechanism for its reported beneficial effects on the intestinal absorption and systemic metabolism of zinc.
(15) In a partition study, picolinic acid increased the aqueous solubility of Zn, Cu, Co and Cd at alkaline pH, but did not transfer the metal to an organic bulk phase of chloroform.
(16) The order of effectiveness against QUIN was kynurenic greater than picolinic greater than quinalidic or anthranilic acid.
(17) cis-Lysene yields alpha-picolinate as a detectable accumulating product, presumably from cyclization of initial 6-aldehyde to dihydropicolinate and spontaneous autoxidation.
(18) The effect was specific for chromium picolinate since neither zinc picolinate nor any of the other forms of chromium tested was effective.
(19) The oxidation of tryptophan to CO2 and metabolites of the glutarate pathway increased 4-5-fold, consistent with an increase in picolinate carboxylase (EC 4.1.1.45) activity.
(20) The action of iron salts and chelators is specific for transferrin receptors, since the expression of other membrane markers of activated human T-lymphocytes (interleukin-2 receptor, insulin receptor, and HLA-DR antigen) is not modified by treatment with iron or picolinic acid.
Pyridine
Definition:
(n.) A nitrogenous base, C5H5N, obtained from the distillation of bone oil or coal tar, and by the decomposition of certain alkaloids, as a colorless liquid with a peculiar pungent odor. It is the nucleus of a large number of organic substances, among which several vegetable alkaloids, as nicotine and certain of the ptomaines, may be mentioned. See Lutidine.
Example Sentences:
(1) The 1-0-methylalduronic-acidmethylesters, obtained by the methanolysis of the polysaccharides, are reduced with boronhydrid to the corresponding methyl glycosides; there are split with acid to the aldoses, which are converted in pyridine with hydroxylamine to the aldoximes and than with acetic anhydride to the aldonitrilacetates, which can be separated by gaschromatography without difficulty.
(2) Vanadate-dependent oxidation of either pyridine nucleotide was inhibited by the addition of either superoxide dismutase or catalase, indicating that both superoxide and hydrogen peroxide may be intermediates in the process.
(3) In both cases, the intensity of cleavage was modulated by the position and the degree of methylation on the pyridinic ring, and results were correlated with cytotoxic activity expressed as the in vitro ID50 values for L1210 leukemia cells.
(4) After an appropriate dilution, the released pyridine-2-thione which has a strong absorbance at 343 nm, is quantified by reading its absorbance in a spectrophotometer at 343 nm.
(5) Oxidation of mitochondrial pyridine nucleotides by alloxan is not mediated by glutathione peroxidase and glutathione reductase and may occur largely nonenzymatically.
(6) The safety and diuretic activity of torasemide (1-isopropyl-3- ([4-(3-methyl-phenylamino)pyridine]-3-sulfonyl)urea) were investigated in a phase I single-blind clinical study.
(7) The non-carcinogens chosen were 4-nitro-o-phenylenediamine, p-phenylenediamine dihydrochloride, 3-nitropropionic acid, dichlorvos, 2-(chloromethyl)pyridine, N-(1-naphthyl)ethylenediamine 2HCl, O-anthranilic acid, 4-nitroanthranilic acid, anilazine and triphenyltin hydroxide.
(8) The alga may be defective in a regulatory mechanism that controls the reoxidation of reduced pyridine nucleotides formed during photosynthesis.
(9) Hydrolysis was inhibited competitively by all pyridine nucleotides when the concentration of Mg [gamma 32P]-ATP was varied between 0.1 mM to 3 mM, but NAD+ was less effective.
(10) Following derivatization with 50 microliters of N-methyl-N-trimethylsilyl trifluoroacetamide-pyridine (1:1) for 20 min at 65 degrees C the samples are analyzed by capillary column gas chromatography-mass spectrometry with selected-ion monitoring.
(11) For each regimen the capsule dose was administered every 8 hours (q 8 h) for 3 days and the plasma profiles of nicardipine and its pyridine analogue (M5) were determined following the last dose on day 4.
(12) Its effects were compared with those of its parent substance CGP 18 137A (2-hydrazino-5-n-butyl-pyridine) which is a general arteriolar dilator.
(13) Reaction of (9) with phosphorus oxychloride in pyridine afforded the desired 6-cyano dienone (4) in 70% yield.
(14) Serial dilutions of pyridine in water are employed for measuring the olfactory detection thresholds of patients.
(15) We have studied the binding of the enzymatically active NAD+ analogue, 3-iodopyridine-adenine dinucleotide, and the inactive analogue, pyridine-adenine dinucleotide to the enzyme horse liver alcohol dehydrogenase using X-ray crystallographic methods.
(16) Computer simulation of spectra using angle selected techniques enabled the assignment of parameters describing the hyperfine and quadrupole interactions for axially bound nitrogen of imidazole in MbOH, of axial pyridine and butylamine in the models, and for the porphyrin nitrogens of the heme in native MbOH.
(17) Since the initial reaction involves internal nucleophilic attack by the pyridine nitrogen, control of the pyridine pKa is critical.
(18) Time-course experiments did not indicate any delay in the peak micronucleus response to benzene caused by either pyridine or xylene.
(19) Similar effects were obtained with local application of 2 microliters of 10(-3) M 4-amino-pyridine to the stimulated cortex.
(20) Based on the analysis of Quantitative Structure--Activity Relationships (QSAR) three representatives of imidazo[4,5-b]pyridine derivatives of predicted high antibacterial activity against Mycobacterium tuberculosis were synthetized and tested bacteriologically.