(n.) A binary compound of methyl with some element; as, aluminium methide, Al2(CH3)6.
Example Sentences:
(1) The coupled dienone-phenol re-arrangement and keto-enol tautomerism of this quinone methide produce the observed 3,4-dihydroxybenzaldehyde.
(2) The cytostatic activity of several triterpenequinone methides isolated from Rzedowskia tolantonguensis and Maytenus horrida (Celastraceae) was evaluated against HeLa cell cultures.
(3) The white colour of the cyst wall of the metacercaria of Microphallus sp., even in the presence of dihydroxy phenol and phenoloxidase, is due to proteins generated through a possible quinone methide interaction.
(4) N-methylation of the imidazole ring(s) produces structures which can form extended quinone methides.
(5) Under anaerobic conditions and with NADPH as a reducing agent, daunomycin is reduced in the presence of spinach ferredoxin: NADP+ oxidoreductase as the enzyme catalyst to its hydroquinone, from which intramolecular elimination of the C-7 glycoside proceeds to provide a quinone methide intermediate.
(6) As with mitomycin C, reduction and quinone methide formation are necessary for alkylation by the title quinone.
(7) Using a purified o-quinone isomerase from the larval cuticle of Sacrophaga bullata and mushroom tyrosinase, we now demonstrate that transiently formed N-acetyldopamine quinone methide from N-acetyldopamine can be trapped by methanol to produce beta-methoxy N-acetyldopamine.
(8) The structure of the adducts is in conformity with the generation and reactions of dehydro NADA quinone methide (or its radical).
(9) These arise by covalent trapping by solvent of a quinone methide intermediate, obtained by rearrangement of the mitomycin c hydroquinone.
(10) Oxidation of the pi system leads to the quinol, 2,6-di-t-butyl-4-hydroxy-4-methyl-2,5-cyclohexadienone, the quinone, 2,6-di-t-butyl-4-benzoquinone, and the quinone methide, 2,6-di-t-butyl-4-methylene-2,5-cyclohexadienone.
(11) Our results suggest that eugenol is oxidized by cytochrome P450 to a reactive quinone methide intermediate which can then covalently modify protein or conjugate with glutathione.
(12) Accordingly, desaturase enzyme preparation contained both o-diphenoloxidase activity and NADA quinone:NADA quinone methide isomerase activity.
(13) Resolution of the NADA desaturase system on Benzamidine Sepharose and Sephacryl S-200 columns yielded the above-mentioned quinone isomerase and NADA quinone methide:dehydro NADA isomerase.
(14) Mouse liver and lung microsomes generate the two quinone methides, and evidence was obtained that both metabolites also are formed in vivo.
(15) It may exist as an equilibrium mixture of the p-quinone and o-quinone methides in solution.
(16) The second process is assigned to reaction of the quinone methide with water yielding hydroxylated product(s) which may subsequently react with remaining quinonoid cation or quinone methide to give dimeric product(s) with broad absorption centreing in the 550 nm region detected 0.5 s after the pulse.
(17) These three conjugates were identical with the products obtained from the chemical reaction of synthetic eugenol quinone methide and glutathione.
(18) Insoluble cuticle-bound enzyme(s) of Manduca sexta pharate pupae, which is known to convert N-acetyldopamine to N-acetylnorepinephrine through the intermediate formation of quinone methide, also converted exogenously supplied N-acetyldopamine quinone to N-acetylnorepinephrine.
(19) The bioactivation of the pulmonary toxin 3-methylindole has been postulated to proceed via the formation of an imine methide.
(20) Mushroom tyrosinase and the recently identified, 4-alkyl-o-benzoquinone: 2-hydroxy-p-quinone methide isomerase were used to investigate the mechanism of biosynthesis of papiliochrome II pigment found in the yellow scales of the papilionid butterflies.
Methyl
Definition:
(n.) A hydrocarbon radical, CH3, not existing alone but regarded as an essential residue of methane, and appearing as a component part of many derivatives; as, methyl alcohol, methyl ether, methyl amine, etc.
Example Sentences:
(1) Phospholipid methylation in human EGMs is distinctly different from that in rat EGMs (Hirata and Axelrod 1980) in that the human activity is not Mg++-dependent, and apparent methyltransferase I activity is located in the external membrane surface.
(2) 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.
(3) Microionophoretically applied excitatory amino acids induced firing of extracellularly recorded single units in a tissue slice preparation of the mouse cochlear nucleus, and the similarly applied antagonist 2-amino-5-phosphonovalerate (2APV) was demonstrated to be a selective N-methyl-D-aspartate (NMDA) receptor antagonist.
(4) A novel bicyclic prostaglandin analogue, (1S)-[1 alpha,2 alpha(Z),3 alpha,4 alpha]-7-[3-[(hexylthio)methyl]-7- oxabicyclo [2.2.1]hept-2-yl]-5-heptenoic acid ((-)-10), and its cogeners were found to be potent antagonists at the TxA2 receptor.
(5) The enzyme was solubilized by Triton X-100 and purified approximately 480-fold by gel filtration and affinity chromatography on alanine methyl ketone-AH-Sepharose 4B.
(6) Glycosyl ceramide concentration was determined by gas-liquid chromatography of the trimethylsilyl ethers of the methyl glycosides.
(7) We have measured the antibody specificities to the two polysaccharides in sera from asymptomatic group C meningococcal carriers and vaccinated adults by a new enzyme-linked immunosorbent assay (ELISA) procedure using methylated human serum albumin for coating the group C polysaccharide onto microtiter plates.
(8) A new type of Escherichia coli mutant which shows increased sensitivity to methyl methane sulfonate but not to UV light or to gamma rays was isolated after mutagenesis with N-methyl-N'-nitro-N-nitrosoguanidine.
(9) The effect of S-adenosylhomocysteine on DNA methylation was examined, and it was found at equal molar concentrations of S-adenosylhomocysteine to to S-adenosylmethionine that DNA methylation was competitively inhibited 50%.
(10) Thermal stabilities (Tm's) of the hybrid between the 2'-O-methyl ribooligomer and the complementary ribooligomer and of the related hybrids are compared.
(11) Intoxicating concentrations of ethanol also inhibit excitatory synaptic transmission mediated by N-methyl-D-aspartate receptors in hippocampal slices from adult rodents.
(12) S-methyl-l-cysteine, 2-hydroxy-4-methiol butyric acid, S-adenosyl-l-methionine, and methionine peptides were the only compounds supporting growth, when substituted for methionine.
(13) Immunocytochemical analyses of the hippocampus demonstrated that alpha-amino-3-hydroxy-5-methyl-isoxazole-4-propionate receptor subunits are present in the cell bodies and dendrites of pyramidal cells.
(14) 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.
(15) These products were identified to be epimers of 5,12(S)-dihydroxy-eicosatetraenoic acid methyl ester (5,12(S)-diHETE-Me) and epimers of 11,12-diHETE-Me.
(16) CCK-8 was acylated with the iodinated aryl azide derivatives, methyl-3-azido-4-hydroxy-5-[125I]iodobenzimidate and N-[4-(4'-azido-3'-[125I]iodophenylazo)benzoyl]-3-aminopropionyl-N- oxy- succinimide.
(17) Substitution of NaCl in the extracellular medium by sucrose, LiCl, or Na2SO4 had no effect on glutamate stimulation of [3H]dopamine release; however, release was inhibited when NaCl was replaced by choline chloride or N-methyl-D-glucamine HCl.
(18) Incubation of membrane with DL-Hcys alone (5 X 10(-5) M), the combination of both Ad (5 X 10(-5)) and DL-Hcys (5 X 10(-5)), or S-adenosyl-L-homocysteine (SAH) (1 X 10(-6)) strongly decreased the methyl ester formation.
(19) 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.
(20) The effects of postnatal methyl mercury exposure on the ontogeny of renal and hepatic responsiveness to trophic stimuli were examined.