(a.) Having the same percentage composition; -- said of two or more different substances which contain the same ingredients in the same proportions by weight, often used with with. Specif.: (a) Polymeric; i. e., having the same elements united in the same proportion by weight, but with different molecular weights; as, acetylene and benzine are isomeric (polymeric) with each other in this sense. See Polymeric. (b) Metameric; i. e., having the same elements united in the same proportions by weight, and with the same molecular weight, but which a different structure or arrangement of the ultimate parts; as, ethyl alcohol and methyl ether are isomeric (metameric) with each other in this sense. See Metameric.
Example Sentences:
(1) Structure assignment of the isomeric immonium ions 5 and 6, generated via FAB from N-isobutyl glycine and N-methyl valine, can be achieved by their collision induced dissociation characteristics.
(2) This is interpreted to mean that the release of fructose from the central complex is faster than the isomerization of the E-NADH complex.
(3) The optical and oxygen binding properties of the reconstituted myoglobins containing two isomeric monoformyl-monovinylhemins were found to be different.
(4) Line broadening detected in several of the high-field nuclear magnetic resonance spectra was attributed to cis-trans isomerization.
(5) Two new isomeric delta-lactones 2 and 3 have been isolated from the marine fungus Helicascus kanaloanus (ATCC 18591).
(6) Two isomeric hydrolysis products of this compound with only three 3(R)-hydroxymyristic acid moieties attached to the disaccharide-1-phosphate were also identified.
(7) Studies on the metabolism of nicotine by rabbit liver microsomal fractions in the presence of 0.01 M sodium cyanide have led to the characterization of two isomeric cyanonicotine compounds.
(8) Kinetic methods are outlined for the distinction between two pathways of substrate binding, which include an isomerization either of the free enzyme or of the enzyme-substrate complex.
(9) In the case of H101S, a mutant protein with measurable isomerizing activity, substrate binding with novel fluorescent properties was observed, possibly the bound pyranose form of xylose under steady-state conditions.
(10) There were consistent isomeric preferences for the R(-) configuration of both DA analogs in stimulating adenylate cyclase (D-1 sites) and in competing for high affinity binding of 3H-spiroperidol (D-2 sites) and of 3H-ADTN (DA agonist binding sites) in striatal tissue, with lesser isomeric differences in the limbic tissue.
(11) Oligosaccharides 3 and 4 and oligosaccharides 5 and 6 were isolated as unresolved isomeric mixtures in fractions B3a and B4a, respectively.
(12) Subsequent fractionation of the original compound into its two isomeric forms resulted in the identification of the isomer primarily responsible for this convulsive activity.
(13) However, the 1500 K simulation produced higher energy structures, even after minimization; in addition, this highest temperature run had many cis-trans peptide isomerizations.
(14) From model compound data, it is shown that the expected rate for isomerism is in satisfactory agreement with the rates actually observed for protein folding.
(15) Re-analysis of PCP and PCP-Na samples with high PCDD contents on a high-resolution glass capillary column showed the presence of 3 hexa- and the 2 heptachlorodibenzo-p-dioxins with nearly constant isomeric ratios.
(16) Such a genomic structure does not appear to have been reported amongst the herpesviruses--all the genomes that do not isomerize either have repeat structures only at the termini, or if present internally, have only direct repeats.
(17) The isomeric N,N-dimethyl-4,5-diphenyl-1H-pyrazole-1-propanamine was completely inactive in the primary antidepressant screens.
(18) Correspondingly, in the case of the histidine-peptides examined only mixtures of the cyclic isomeric compounds were isolated and structurally characterized by 1H-NMR analysis.
(19) In contrast to the biphasic unfolding of the wild-type nuclease, the unfolding of the mutant is represented by a single-phase reaction, indicating that the biphasic unfolding for the wild-type protein is caused by cis-trans isomerization about the prolyl peptide bond in the native state.
(20) In order to prepare a completely light-stable rhodopsin, we have synthesized an analog, II, of 11-cis retinal in which isomerization at the C11-C12 cis-double bond is blocked by formation of a cyclohexene ring from the C10 to C13-methyl.
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.