What's the difference between methene and methylene?
Methene
Definition:
(n.) See Methylene.
Example Sentences:
(1) Chemiluminescence appears to result from a side reaction involving singlet oxygen attack on the alpha-methene bridge, yielding a dioxetane.
(2) At high concentrations, they inhibited heme oxygenase [heme, hydrogen-donor:oxygen oxidoreductase (alpha-methene-oxidizing, hydroxylating), EC 1.14.99.3] in vitro.
(3) Selenium was found to be a novel regulator of cellular heme methabolism in that the element induced both the mitochondrial enzyme delta-aminolevulinate synthase [succinyl-CoA:glycine C-succinyltransferase (decarboxylating); EC 2-3-1-37] and the microsomal enzyme heme oxygenase [heme, hydrogen-donor:oxygen oxidoreductase(alpha-methene-oxidizing, hydroxylating); EC 1-14-99-3] in liver.
(4) Molecular-mechanics calculations with the three-dimensional structural co-ordinates of catalase shows that these proportions of products can be accounted for by the relative accessibility of the four methene bridges to a haem-linked oxygen molecule, thus further confirming Brown's [(1976) Biochem.
(5) Porphyrins with aromatic substitutions at the methene bridges (2a, 2b) did not inhibit the conversion of heme to bilirubin, even at relatively high concentrations.
(6) A model is proposed in which an oxygen molecule, bound to the haem iron atom, attacks a methene-bridge carbon atom in an intramolecular reaction.
(7) We investigated two compounds with substitutions at the 2 and 4 position of the porphyrin ring, iron deuteroporphyrin 2,4 disulfonic (1a) and iron deuteroporphyrin 2,4 bis glycol (1b), and two compounds with substitutions of aromatic groups on the methene bridges of the porphyrin molecule, meso-tetra-4-carboxyphenyl-porphine (2a) and meso-tetra-4-sulfonatophenyl-porphine (2b).
(8) Heme oxygenase (decyclizing) [heme,hydrogen-donor:oxygen oxidoreductase (alpha-methene-oxidizing, hydroxylating), EC 1.14.99.3] is greatly induced in the kidney by the administration of nickel or tin.
(9) Compounds derived from phosphoenolpyruvate by replacing the methene group by similarly hydrophobic groups such as hydrogen or the methyl group were permeant but those with the hydrophilic hydroxymethyl group were impermeant.
(10) 45% of the haem groups have been cleaved at the alpha-methene bridge, 55% at the beta-bridge and a trace at the delta-bridge.
(11) It is concluded that (a) the CO produced during lipid peroxidation originates from a source different from haem and (b) the degradations of haem caused by lipid peroxidation and 2-allyl-2-isopropylacetamide do not involve to any significant extent evolution of the methene-bridge carbon of haem as CO.
(12) Specificity of macrocyclic ring cleavage is explained on the basis of the different accessibilities of the bound oxygen molecule to the four methene bridges.
(13) A scheme for the oxidation of iron(III) oxyporphyrin to iron(II) verdoheme by O2 that proposes a mechanism for the expulsion of CO and the replacement of a methene bridge of the porphyrin ring by an oxa bridge is presented.
Methylene
Definition:
(n.) A hydrocarbon radical, CH2, not known in the free state, but regarded as an essential residue and component of certain derivatives of methane; as, methylene bromide, CH2Br2; -- formerly called also methene.
Example Sentences:
(1) The effect of 4,4'-methylene bis(2-chloroaniline) (MOCA), 4,4'-methylene dianiline (MDA) and 4,4'-sulphonyldianiline (Dapsone) in vivo on xenobiotic biotransformation in male rat liver was studied.
(2) It was concluded that the detachment of the oxaloyl residue from oxaloacetate and its replacement by a proton proceed with inversion of configuration at the methylene group which becomes methyl during the hydrolysis.
(3) After methylene blue, the gradient in resting potential across the circular layer was greatly reduced or abolished.
(4) Furthermore, Methylene Blue contamination of the standard stain increased the rate of error in image analysis of white blood cell nuclei due to variations of staining intensity.
(5) The purpose was to show whether or not the methylene-blue test can be postponed to the second day.
(6) Baseline evaluation revealed that 17 (32%) patients had high turnover (HTOP), and 36 (68%) normal turnover osteoporosis (NTOP) as assessed by measurement of whole body retention (WBR) of 99mTc-methylene diphosphonate.
(7) Methylenation of the delta6 double bond with dimethyloxosulfonium methylide proceeds steroselectively from the beta side of the molecule.
(8) The amount of formazan obtained after incubating vital cells with Meldola Blue as electron carrier was greater than that obtained with Methylene Blue, menadione, 2,6-dichloroindophenol, 1-methoxyphenazine methosulphate or phenazine methosulphate.
(9) The NMR spectra of the two tRNA species in the region between 0 and 4 ppm below 4,4-dimethyl-4-silapentane-1-sulfonic acid (DSS) (methyl and methylene region) were the same except for the absence of the lowest field peak at 3.8 ppm in tRNAMet f3, thus unequivocally identifying this resonance at the methyl group of m7G47 of tRNAMet f1.
(10) The effects of methylene blue on vascular tone and responses to hypoxia and acetylcholine were reversible, and responses returned to control value after the infusion was terminated.
(11) NMOP-d5, with deuterium in the N-methyl and in the alpha-methylene, gave rise only to 7-MeG containing three deuterium atoms.
(12) The beta,gamma-methylene analogue of ATP was reactive in exchange reactions with [(14)C]AMP.
(13) Inactivation is due to alkylation by 2-methylene-3(2H)-furanone, a decomposition product of the enzymic product 3'-keto-2'-deoxyuridine triphosphate.
(14) The method comprised adsorption on Extrelut column from alkaline plasma, elution with diethyl ether-methylene chloride, evaporation in the presence of 0.01 M hydrochloric acid and injection of the acid solution onto a mu Bondapak C18 column, using acetonitrile-0.025 M potassium dihydrogenphosphate as mobile phase and ultraviolet detection at 210 nm.
(15) The linear, nonbranched segments of the omega-cyclohexyl chains in 13cyPC are closely packed with the all-trans methylene zig-zag planes oriented parallel to each other.
(16) Clonidine induced a contraction when endothelium was removed or muscle was treated with methylene blue.
(17) The effects of bradykinin, but not glyceryl trinitrate, were partially restored after removing methylene blue.
(18) The kinetic behavior observed at steady-state using different concentrations of the substrates ATP and fructose-6-phosphate and the pattern of inhibition by the substrate analogs adenylyl-(beta, gamma-methylene)-diphosphonate and D-arabinose-5-phosphate are consistent with a random sequential mechanism in rapid equilibrium, rather than with an ordered binding as was suggested earlier.
(19) Replacement of the cysteinylglycyl moiety with cysteine afforded 20, which retained significant antagonist activity, while lengthening or shortening the lipid tail by five methylene groups resulted in complete loss of activity.
(20) The pro-S 4'-methylene proton of pyridoxamine phosphate is removed during the reaction, and the product is primarily L-tryptophan.