(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.
Pyridyl
Definition:
(n.) A hypothetical radical, C5H4N, regarded as the essential residue of pyridine, and analogous to phenyl.
Example Sentences:
(1) Five derivatives of 2-(3-aminopropionyl)-1-(3-pyridyl)-1,2,3,4-tetrahydro-beta-carboline (2a-e) were obtained, which yielded, as a result of reduction with LiAlH4, five respective 2-aminopropyl-derivatives (3a-e).
(2) Maximum potency was displayed by N-tert-pentyl-N'-3 pyridyl-N"-cyanoguanidine (20).
(3) The oxazolidinone compound E3709, which contains a 4-pyridyl group, was found to be more active in vitro than other members of this series, such as DuP 721.
(4) Probing of the active site of microsomal cytochrome P-450 was carried out with a spin label derived from 2-methyl-1,2-bis(3-pyridyl)-1-propanone (metyrapone).
(5) This metabolite was isolated from the urine of chronically dosed dogs and was identified by mass, nuclear magnetic resonance (NMR), and infrared spectrometry as the N-oxide, 2-phenyl-1-(4-pyridyl)-3-(4-pyridyl-1-oxide)-2-propanol.
(6) Electron spin resonance (ESR) spin trapping methodology has been used to study the reactions of manganese dusts with glutathione, employing alpha-(4-pyridyl-1-oxide)-N-tert-butyl-nitrone (PBN) and 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as spin traps.
(7) The three N-pyridyl-2-phenylsuccinimides [N-(3-methyl-2-pyridyl)-2-p-chlorophenylsuccinimide (I-11); N-(3-methyl-2-pyridyl)-2-phenylsuccinimide (I-10) and N-(3-pyridyl)-2-phenylsuccinimide (I-6)], examined by means of X-ray structure analysis, have been previously subjected to extensive pharmacological screening, with regard to their anticonvulsive activity.
(8) In attempt to increase hydrophilicity, 1-substituted 2(3'-pyridyl)-5-nitrobenzimidazoles were prepared by reaction of 2-(3'-pyridyl)-5(6)-nitrobenzimidazole(4) with alkyl epoxides or ethyl chloroacetate.
(9) In toxicological studies, the test compound FOE 3440 A, a [(3,5-dichloro-2-pyridyl)oxy]phenoxypropanoate with herbicidal properties, produced a severe increase in weight and an intensive induction of monoxygenases activity in the mouse, but not in the rat.
(10) Large differences have been observed between the physical, chemical, and insecticidal properties of four representatives of a closely related series of O,O-dialkyl O-(3,5,6-trichloro-2-pyridyl) phosphates and phosphorothioates.
(11) Levels of 4-hydroxy-1-(3-pyridyl)-1-butanone (HPB) were used to measure the extent of methyl hydroxylation, whereas levels of the aldehyde, 4-oxo-1-(3-pyridyl)-1-butanone (OPB), were used to quantify the extent of methylene hydroxylation.
(12) Pyridyl-biphenylyl-acetamide (diphenpyramide, Z-876) is a new bisphenylalcanoic derivative with marked anti-inflammatory, analgesic, antipyretic and uricosuric properties.
(13) Effects of the K+ channel blocking agent, glyburide, on the actions of two K+ channel openers, BRL 34915 (cromakalim) and P 1060 (Leo), a potent pinacidil derivative (N-(t-butyl)-N"-cyano-N'-3-pyridyl-guanidine), were ascertained.
(14) HPLC-EPR analyses of the reaction mixtures of microsomal suspensions incubated with ADP, ferric chloride, NADPH and alpha-(4-pyridyl-1-oxide)-N-tert-butylnitrone (4-POBN) were performed.
(15) The nicotine derived N-nitrosamine, 4-(methylnitro-samino)-1-(3-pyridyl)-1-butanone (NNK), is a potent respiratory carcinogen in the Syrian golden hamster.
(16) The nephrotoxicity of (6R,7R)-7-(2-[3,5-Dichloro-4-oxo-1(4H)-pyridyl]-acetamido)-3-([(5-methyl-1,3,4-thiadiazol-2-yl)-thio]methyl)-8-oxo-5-thia-1-azabicyclo[4,2,0]oct-2-ene-2-carboxylic acid (cefazedone, Refosporen), cephalothin, cefazolin and gentamicin was investigated by the determination of alanine-amino-peptidase (AAP) in urine of healthy volunteers.
(17) 4-(3-Pyridyl)thiazole and 2-methylimidazo[1,2-a]pyridine derivatives with anticholinergic antisecretory activity were synthesized.
(18) The particularly interesting compound (E)-1-(3-chlorophenyl)-5-[2-(3-pyridyl)ethenyl]-1H,7H-pyrazolo[1,5-a]- pyrimidine-7-one was chosen for wider pharmacological investigation.
(19) 3 Only half the compounds blocked the inhibitory effects of ATP, and all of these had a chemically reactive group (nitro, methoxy or pyridyl) in the 2'2-position.
(20) Of the 12 P-450 forms, P-450 1A2 had the highest activity in catalyzing the conversion of NNK to the keto alcohol, 4-hydroxy-1-(3-pyridyl)-1-butanone.