(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.
Picoline
Definition:
(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.