methyln.

Brit.

/ˈmiːθʌɪl/,

/ˈmɛθʌɪl/,

/ˈmɛθ(ᵻ)l/, U.S.

/ˈmɛθ(ə)l/

Forms: 1800s methule, 1800s methyle, 1800s– methyl.

Origin: A borrowing from German. Etymon: German Methyl.

Etymology: < German Methyl (F. Wöhler 1836, in Jahres-Bericht über die Fortschritte der physischen Wissensch. 15 381), shortened < Methylen methylene n., after Swedish metyl (Berzelius 1835, in Årsberättelser om vetenskapernas framsteg, afgifne af Kongl. Vetenskaps-Academiens embetsmän 376), itself shortened < metylen methylene n., after etyl ethyl n. (compare -yl suffix). Compare French méthyle ( A. J. L. Jourdan tr. Berzelius Traité de chim. (1839) III. 403).

Chemistry.

The hydrocarbon radical present in wood spirit (methanol) and its derivatives; the group or radical CH₃—.In earliest use, not clearly distinct from methylene n.

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the world > matter > chemistry > organic chemistry > hydrocarbons > [noun] > hydrocarbon radicals > named, by number of carbon atoms > one

methylene1835

methyl1840

methene1867

1840 J. Berzelius in London & Edinb. Philos. Mag. 16 6 For the sake of brevity, E will be = C⁴H¹⁰, ethyle; Me = C²H⁶, methyle; F = C²H², formyle.

1844 G. Fownes Man. Elem. Chem. iv. 416 Compounds of methyle, with fluorine, cyanogen, and sulphur, have also been obtained.

1847 Amer. Jrnl. Sci. 54 333 The same is true of..oxyd of methyle and alcohol.

1849 Jrnl. Chem. Soc. 2 263 The mixture consisted of methyl and the hitherto unisolated radical ethyl.

1879 J. Tyndall Fragm. Sci. (ed. 6) I. xvii. 447 The positions of chloroform and iodide of methyl are inverted.

1929 Chem. Abstr. 23 5159 It is concluded..that the reactive substance in all these expts. is free methyl.

1957 Ann. Rev. Biochem. 26 451 The methyl group can be derived from acetate methyl.

1974 Chem. in Brit. (Royal Soc. Chem.) 10 54/1 The methyl goes on to the carbon and the charge is neutralized by the nitrogen.

1989 Chem. Senses 14 805 Modification or substitution of the guanidin[i]um group by other basic groups including amine, methyl or dimethylamine..resulted in loss of stimulatory ability.

Compounds

C1. General attributive and appositive, esp. in methyl group, methyl radical.

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1844 G. Fownes Man. Elem. Chem. Index Methyle-compounds.

1861 Jrnl. Chem. Soc. 13 323 In exceptional cases only have I worked in the methyl-series.

1883 Science 23 Feb. 75/1 By heating xanthine-silver [i.e. the silver compound of xanthine] with methyl iodide, a methyl group was introduced.

1899 T. C. Allbutt et al. Syst. Med. VIII. 577 [Cacodylic acid] is a combination of arsenic with methyl radicals.

1922 J. J. Sudborough Bernthsen's Text-bk. Org. Chem. (new ed.) xl. 598 Codeine..is a methyl derivative of morphine.

1926 J. Read Text-bk. Org. Chem. xi. 203 By replacing six hydrogen atoms in the molecule of the magenta dye, pararosaniline, with six methyl groups,..is produced.

1951 Jrnl. Biol. Chem. 189 203 Methionine is the methyl donor for the methylation of both nicotinamide and guanidoacetic acid.

1955 B. C. L. Kemp Elem. Org. Chem. (new ed.) xxiv. 306 Salicylic Acid, 1 : 2 C₆H₄(OH)COOH, occurs naturally in the form of its methyl ester, which is the main constituent of oil of wintergreen.

1962 J. T. Marsh Self-smoothing Fabrics xviii. 300 Free methyl radicals might possibly react with the quinoid group..and produce a methoxyl group which would destroy the chromophoric structure.

1965 J. R. Dyer Applic. Absorption Spectroscopy Org. Compounds iv. 66 Under higher resolution the peaks of ethyl alcohol..attributed to methylene and methyl protons appear as multiplets.

1967 Experientia 23 793/1 We..wish to report the isolation of picene and chrysene, along with evidence that methyl homologs of these are also present.

1985 P. J. Wingate Before Bridge xx. 200 Then he gave me the job of learning how to insert an angular methyl group into the napthalene molecule.

1991 Economist 13 July 105/2 One way to turn genes off is to plaster molecules called methyl groups all over the DNA from which the gene is made.

2000 Biochem. Jrnl. 346 475 Methionine adenosyltransferase is an essential cellular enzyme which catalyses the formation of S-adenosylmethionine, the principal methyl donor and precursor for polyamines.

C2. Forming the systematic, semi-systematic, or trivial names of organic compounds containing one or more methyl groups.Also with locant.In systematic substitution nomenclature methyl is now normally written as one word with the item to which it is prefixed. Two-word names are used chiefly in functional class nomenclature, where the second (or final) word is a class term, as of an acid or acid derivative, oxygen or carbonyl compound, halide or pseudohalide, etc. In later systematic use, therefore, there is usually a semantic difference between the two forms, as between methyl malonate (the dimethyl ester of malonic acid) and methylmalonate (a salt or ester of methylmalonic acid), although this rule of chemical nomenclature is not always applied consistently.

a. spec. prefixed to the name of a parent compound to indicate substitution of a methyl group for a hydrogen atom or other substituent, as methylacetophenone, methyl-codeia, etc.

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1850 C. G. B. Daubeny Introd. Atomic Theory (ed. 2) viii. 240 Methylaniline, where the second atom is replaced by methyle instead of ethyle.

1866 W. Odling Lect. Animal Chem. 45 Leave the urea and methylamine residues combined with one another in the form of methyl-uramine or methyl-guanidine.

1868 Rep. Brit. Assoc., Sections 38 Iodide of methylacetonamine.

1874 A. B. Garrod & E. B. Baxter Essentials Materia Medica (ed. 4) 201 The hypnotic effect of codeia is wholly destroyed by its conversion into methyl-codeia.

1885 I. Remsen Introd. Study Compounds of Carbon (1888) 357 Methyl-sulphonic acid..methyl-carbonic or acetic acid.

1934 C. C. Steele Introd. Plant Biochem. xxi. 237 The terpenes and camphors are derived from p-methyl-isopropyl-cyclohexane, C₁₀H₂₀, known as menthane.

1964 N. G. Clark Mod. Org. Chem. xxiii. 479 The ketones are frequently employed..as ingredients in perfumery. Some simple derivatives possess quite delightful odours, for example, p-methylacetophenone (hawthorn).

b. spec. forming the names of organometallic compounds in which the metal is bound to the carbon atom of a methyl group, as methylcopper, methyl-lithium, methyl-tin, etc. Cf. methide n. 1.

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1850 Q. Jrnl. Chem. Soc. 2 298 It is highly probable that this body, which for the present I propose to call Zincmethyl, plays the part of a radical.]

1920 Chem. News 120 229/1 It is found that methyl tin trichloride forms double salts with various amine hydrochlorides.

1935 Jrnl. Amer. Chem. Soc. 57 1063/1 Methylmagnesium chloride.

1952 Jrnl. Org. Chem. 17 1630 The cuprous chloride then reacted with more of the Grignard reagent or organolithium compound to give a bright yellow, ether-insoluble methylcopper compound.

1965 Steroids 6 111 (title) The reaction of 3-alpha-acetoxy-4-alpha, 5-alpha-epoxy-cholestane (I) with methyllithium and with methylmagnesium iodide.

1979 Analyt. Chem. 51 12 (title) Separation and determination of nanogram amounts of inorganic tin and methyltin compounds in the environment.

1981 Proc. National Acad. Sci. U.S.A. 78 1318/2 The methylrhodium complex [μCH₃Rh(1,5-cyclooctadiene)]₂ was obtained in high yield from methyllithium and the chlororhodium cyclooctadiene dimer.

1991 Science 252 1267/2 The best description of methyllithium is CH₃⁻Li⁺ with little covalent character.

1996 Chemosphere 32 1983 Organotin compounds, mainly methyltin and butyltin.., were detected in distributed water samples from six municipalities.

C3.

methyl alcohol n. = methanol n.

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1847 Amer. Jrnl. Sci. 54 333 Methyl alcohol.

1872 Jrnl. Chem. Soc. 25 234 (heading) Reduction of formic acid to formaldehyde and methyl alcohol.

1922 Jrnl. Chem. Soc. A. 122 i. 47 Ergotamine, obtained in crystallisable form from ergot, on treatment with methyl alcohol gives a new, less active alkaloid, ergotaminine.

1946 Nature 26 Oct. 592/2 The increased ionicity of the C—O bond in ethyl alcohol relative to C—O in methyl alcohol.

1968 Brain 91 220 Illicit gin known to contain a high concentration of methyl alcohol is consumed in large quantities in the coastal areas.

1991 South Aug. 58/2 Bio-diesel is made by mixing rape seed oil..with Methyl Alcohol to produce Methyl RSO.

methyl bromide n. a highly toxic gas, CH₃Br, which is liquid below 3°C and is used in organic synthesis and as a fumigant; also called bromomethane.

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1850 Philos. Trans. (Royal Soc.) 140 113 Bromide of methyl.]

1871 Proc. Royal Soc. 1870–71 19 504 When..the action of hydrobromic acid [on codeia] is prolonged, methyl bromide is evolved in some little quantity.

1929 Jrnl. Amer. Chem. Soc. 51 2535 We have found methyl bromide to be a satisfactory methylating agent.

1948 New Biol. 4 71 The most common fumigants in use in this country are..methyl bromide, [etc.].

1990 C. Rose Dirty Man of Europe (1991) x. 245 She has been experiencing ‘general weakness, giddiness, numbness and shudderings’ after working in a field fumigated with methyl bromide.

methyl chloride n. a gas, CH₃Cl, which is liquid below 12°C and is used as a refrigerant; also called chloromethane.

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1849 Philos. Trans. (Royal Soc.) 139 381 The time of air was 973, 973 seconds; of chloride of methyl, 592, 587 and 582 seconds.]

1872 Proc. Royal Soc. 1871–2 20 282 No perceptible evolution of methyl chloride took place.

1945 Soap & Sanitary Chemicals Apr. 125/3 Methyl chloride is an excellent propellant gas for aerosols to be used against insects out of doors.

1990 Science 249 160/1 The most abundant halohydrocarbon species in the upper atmosphere is methyl chloride.

methylchloroform n. a non-flammable toxic volatile liquid, CH₃CCl₃, used as a solvent, an aerosol propellant, and for metal degreasing; 1,1,1-trichloroethane.

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1888 Jrnl. Chem. Soc. 54 841 Ethylenediphenylsulphone is the chief product obtained when methylchloroform is heated with sodium benzenesulphinate.

1969 Arch. Environmental Health 19 467 Methyl chloroform can be specifically detected in a peripheral blood sample of an exposed individual.

1990 Sci. News 28 July 62/1 Used by many industries as an electronics solvent, methylchloroform depletes the ozone layer and contributes to global warming.

methylcholanthrene n. [after German Methyl-cholanthren (H. Wieland & E. Dane 1933, in Zeitschr. f. Physiol. Chem. 219 241)] a highly mutagenic and carcinogenic polycyclic hydrocarbon, C₂₁H₁₆, which is widely used in cancer research.

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1933 Chem. & Industry 11 758/2 In our selenium dehydrogenation experiment we obtained..a yellow hydrocarbon, evidently identical with the ‘methylcholanthrene’ of Wieland and Dane.

1984 M. J. Taussig Processes in Pathol. & Microbiol. (ed. 2) vi. 768 A two-stage process can be shown to be involved in induction of malignant neoplasms: for example, sesame seed oil injections promote the development of sarcomas in rats after feeding methylcholanthrene.

methyl cyanide n. (a) = methyl isocyanide n. (now rare); (b) = acetonitrile n.

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1856 Philos. Trans. (Royal Soc.) 146 453 Acetonitrile, or Cyanide of Methyl.]

1871 H. E. Roscoe Lessons Elem. Chem. (new ed.) xxix. 320 The cyanogen is connected with the methyl by the atom of nitrogen, and this body is therefore called methyl cyanide. The other isomer has been called Acetonitril.

1877 H. Watts Fownes's Man. Chem. (ed. 12) II. 92 Methyl cyanide, Ethenyl-nitril or Acetonitril, boils at 77°.

1906 H. F. Morley & M. M. P. Muir Watts' Dict. Chem. III. 305/2 Methyl cyanides, acetonitrile and methyl carbamate.

1964 N. G. Clark Mod. Org. Chem. xiii. 259 The cyanides (nitriles) form a homologous series of the general formula C_nH_2n+1.CN... The simplest method of naming these compounds is to call them alkyl cyanides, so that the first member of the series is methyl cyanide, CH₃.CN.

1980 Proc. Royal Soc. A. 370 241 (caption) Detection of the heterodimer formed between methyl cyanide and hydrogen fluoride by means of its gas-phase rotational spectrum.

5-methylcytosine n. a methylated form of the pyrimidine base cytosine that is involved in the control of transcription in eukaryotes.

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1903 Amer. Chem. Jrnl. 29 495 The natural assumption is that the analogous thymine..results from the decomposition of a corresponding base, the as yet undiscovered 5-methylcytosine.

1989 B. Alberts et al. Molecular Biol. Cell (ed. 2) x. 583 Vertebrate DNAs contain 5-methylcytosine.., which has the same relation to cytosine that thymine has to uracil and likewise has no effect on base-pairing.

2000 Mutation Res. 462 137 Thymine produced at these sites by the hydrolytic deamination of 5-methylcytosine is removed by thymine-DNA glycosylase.

methyldopa n. Pharmacology (more fully alpha-methyldopa) the compound 3-(3,4-dihydroxyphenyl)-2-methyl-L-alanine, C₁₀H₁₃NO₄, which is used as an antihypertensive agent.

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the world > health and disease > healing > medicines or physic > medicines for specific purpose > preparations treating or preventing specific ailments > [noun] > for blood-pressure disorders

Neo-Synephrine1934

Priscol1938

phenylephrine1947

hexamethonium1949

Priscoline1949

methonium1950

hydralazine1952

phentolamine1953

methyldopa1954

pentolinium1954

mecamylamine1955

hydrochlorothiazide1958

pempidine1958

guanethidine1959

hydroflumethiazide1959

thiazide1959

pheniprazine1960

pargyline1961

vasodepressor1961

alpha blocker1965

clonidine1969

prazosin1970

timolol1973

1954 Arch. Biochem. & Biophysics 51 456 Two compounds, α-methyl-3,4-dopa (α-MD) and α-methyl-3-hydroxyphenylalanine, respectively, added in a low range of concentrations, accelerated, and at higher concentrations, inhibited, kidney dopa decarboxylase.

1961 N.Z. Med. Jrnl. 60 569/2 Methyl dopa, like other potent hypotensive agents, produces side-effects including fatigue.

1972 Materials & Technol. V. xxi. 792 Methyldopa and pargyline cause the replacement of noradrenaline by a weaker transmitter.

1984 M. J. Taussig Processes in Pathol. & Microbiol. (ed. 2) ii. 92 For instance, α-methyldopa, a drug used in treatment of hypertension, induces autoimmune haemolytic anaemia.

2000 S. Afr. Med. Jrnl. 90 156 Methyldopa was the antihypertensive used most frequently for the treatment of mild to moderate hypertension.

methyl ether n. (a) dimethyl ether, (CH₃)₂O; (b) any ether in which one of the groups attached to the oxygen atom is a methyl group.

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1852 H. Watts tr. L. Gmelin Hand-bk. Chem. VII. 257 Methyl-ether gas..burns with a flame like that of alcohol.

1854 J. Scoffern in Orr's Circle Sci., Chem. 109 Butyric ether and butyric methyl ether.

1926 H. G. Rule tr. J. Schmidt Text-bk. Org. Chem. 119 Methyl ether, CH₃.O.CH₃, is obtained even more readily under these conditions.

1931 Jrnl. Chem. Soc. 273 The Friedel-Crafts reaction has now been extended to the coupling of malonyl chloride..with methyl ethers of resorcinol.

1967 I. L. Finar Org. Chem. (ed. 5) I. vii. 166 Dimethyl ether (methyl ether) is prepared industrially by passing methanol vapour at 350–400°, and at a pressure of 15 atmospheres, over aluminium phosphate as a catalyst.

1996 Proc. National Acad. Sci. U.S.A. 93 12828/1 MMAS-3 O-methylates this secondary alcohol to form the corresponding methyl ether.

methyl ethyl ketone n. butanone, CH₃CH₂COCH₃; abbreviated MEK.

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the world > matter > chemistry > organic chemistry > ketones > [noun] > used as solvents

mesityl oxide1868

methyl ethyl ketone1876

methyl isobutyl ketone1888

MEK1930

hexone1938

1876 Jrnl. Chem. Soc. 29 897 By the reduction of methyl-ethyl ketone, pinacone C₈H₁₈O is obtained.

1938 H. P. Starck Princ. Org. Chem. vii. 186 Methyl ethyl ketone was formerly used as a solvent in the preparation of cordite from gun cotton and nitroglycerine.

1959 Times Rev. Industry Aug. 98/1 Methylethylketone for removing waxy materials.

1992 Earth Matters Autumn 2/1 Two plants..are releasing more of the toxic chemicals xylene, benzene and methyl ethyl ketone to water than 26,000 US firms combined!

methylglyoxal n. a toxic aldehyde, CH₃COCHO, which occurs naturally as a by-product of carbohydrate metabolism.

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the world > matter > chemistry > organic chemistry > aldehydes or alkanals > [noun] > miscellaneous named aldehydes > others

acrolein1841

metaldehyde1841

trichlorocetaldehyde1845

valeral1852

toluic aldehyde1857

glyoxal1858

acraldehyde1864

propionic aldehyde1866

lauric aldehyde, ether1868

salicylaldehyde1869

dialdane1876

isovaleraldehyde1883

rhodinal1892

propenal1894

oxaldehyde1895

methylglyoxal1898

hadromal1899

malondialdehyde1904

pyruvic aldehyde1909

trioxan1915

plasmal1925

1898 Jrnl. Chem. Soc. 74 i. 224 Methylglyoxal is formed from dihydroxyacetone..when the latter is distilled with dilute sulphuric acid.

1913 Jrnl. Biol. Chem. 14 423 The catalyst..effects the rapid conversion of methyl glyoxal into lactic acid.

1951 Jrnl. Biol. Chem. 190 685 The first step consists in a condensation reaction between methylglyoxal and glutathione catalyzed by an enzyme referred to in this paper as glyoxalase I.

1962 A. Pirie Lens Metabolism 431 Experiments were done in the hope of detecting methylglyoxal which Salem and Crooke (1950) stated was formed from hexosediphosphate by liver.

1991 Jrnl. Agric. & Food Chem. 39 2231/1 The interaction of several labile coffee constituents including aliphatic dicarbonyl compounds, e.g., methylglyoxal.

methyl green n. a green dye of the triphenylmethane series, C₂₇H₃₅BrClN₃, used especially as a histological stain and indicator for DNA.

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the world > matter > colour > named colours > green or greenness > green colouring matter > [noun] > pigment or dye > dyes and dyestuffs

greening worta1200

greening weeda1399

spinach-green1845

emeraldine1864

methyl green1873

malachite green1875

viridine1875

1873 Jrnl. Chem. Soc. 26 1272 Another methyl group may be added by the action of methyl chloride on methyl violet, forming the compound known as ‘methyl green’.

1906 Practitioner Nov. 666 Stained with pyronin and methyl green, the nuclei were large, rounded, pale, and contained chromatin.

1922 J. J. Sudborough Bernthsen's Text-bk. Org. Chem. (new ed.) xxx. 517 Such additions cause a change of colour from violet to green; thus the compound [formula] is the dye methyl green or light green.

1973 R. G. Krueger et al. Introd. Microbiol. v. 188/2 The cell wall can be visualised..by treatment of the cell with specific cell wall stains, such as phosphomolybdic acid and methyl green.

1994 Denver Post 30 Jan. t1/3 All the new electrochemical pastels..demure, Congo ruby, methyl green, [etc.].

methyl isobutyl ketone n. a liquid ketone, (CH₃)₂CHCH₂COCH₃, which is manufactured by the hydrogenation of mesityl oxide and widely used as a solvent; 4-methylpentan-2-one; cf. hexone n. 2.

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the world > matter > chemistry > organic chemistry > ketones > [noun] > used as solvents

mesityl oxide1868

methyl ethyl ketone1876

methyl isobutyl ketone1888

MEK1930

hexone1938

1888 Jrnl. Chem. Soc. 54 125 Its ketone..is therefore identical with methyl isobutyl ketone.

1960 Times Rev. Industry Dec. 16/3 The chloride is dissolved in water, and then treated with an organic solvent called methylisobutyl ketone (MIBK) which extracts the iron.

1973 H. M. Stanley in E. G. Hancock Propylene i. 9 The Shell Oil Company..in 1937–8 commenced the manufacture of acetone derivatives, including diacetone alcohol, mesityl oxide and methylisobutyl ketone.

methyl isocyanate n. a highly toxic volatile liquid, CH₃NCO, used in the manufacture of insecticides and herbicides.

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1894 G. M'Gowan tr. A. Bernthsen Text-bk. Org. Chem. (ed. 2) 121 Methylamine, ethylamine, etc., are obtained by treating methyl or ethyl etc. iso-cyanate with potash solution.

1985 Listener 6 June 7/1 Workers at the plant used to refer jokingly to the methyl isocyanate (MIC) used to make pesticides as ‘lions that could gobble up the people of Bhopal’.

methyl isocyanide n. a toxic liquid, CH₃NC.

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1889 G. M'Gowan tr. A. Bernthsen Text-bk. Org. Chem. 110 Methyl iso-cyanide, CH₃.NC.B.Pt. 58°.

1966 New Statesman 2 Dec. 826/2 Methyl isocyanide..is chemically very like nitrogen yet much easier to work with.

† methyl malonate n. Obsolete rare the dimethyl ester of malonic acid, C₅H₈O₄.

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1875 Jrnl. Chem. Soc. 28 142 Methyl malonate, C₃H₂(CH₂)₂O₄, which was obtained by treating the silver-salt with methyl iodide, is a mobile liquid bearing an ethereal smell, and boiling at 175°–180°.

methyl mercaptan n. a flammable gas with a pungent odour, CH₃SH, which is used as an organic reagent and in the manufacture of jet fuels and pesticides.

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1844 G. Fownes Man. Elem. Chem. 420 Methyl-mercaptan..is a colourless liquid, of powerful alliaceous odour.

1962 Which? Mar. 91/1 Our final choice was methyl mercaptan, which smells like boiled cabbage and is a constituent of the smell of drains.

1997 New Scientist 26 July 37/2 If a wine has too much methyl mercaptan in it, you think of burning rubber.

methylmercury n. (a) a highly toxic cation, CH₃Hg⁺, compounds of which were formerly used as seed disinfectants, and which may be synthesized in the environment by microbial methylation of inorganic mercury compounds; (b) the toxic liquid dimethylmercury, (CH₃)₂Hg (rare).

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the world > matter > chemistry > elements and compounds > metals > specific elements > mercury > [noun] > compounds

sublimate1543

precipitate1563

red mercury1582

quicksilver extinct1610

red precipitate1676

mercury fulminate1904

methylmercury1915

mercurochrome1919

mercurial1971

1915 P. E. Spielmann tr. V. von Richter Org. Chem. 188 Silver nitrate changes it to methyl mercury nitrate, CH₃Hg.ONO₂.

1935 Jrnl. Agric. Sci. 25 636 Dusts were prepared with a range of methyl mercury compounds of varying solubilities.

1970 Atlantic Sept. 25 The Swedes solved their problem by banning the use of one extremely pervasive compound, methylmercury, and shipping it to the United States, where it is now used to treat wheat seed.

1981 M. C. Gerald Pharmacol. (ed. 2) xxxi. 605 In 1969, three members of a New Mexican family of nine were poisoned and suffered severe brain damage after eating a hog that was fed on grain containing methylmercury.

1991 Sea Frontiers Mar. 6/1 The behavioral differences between the two groups of cats may be caused by high levels of methylmercury in the tuna [in cat food].

methyl methacrylate n. the methyl ester of methacrylic acid, CH₂=C(CH₃)COOCH₃, which is a volatile liquid that readily polymerizes to form a transparent plastic used as a glass substitute, sold under names such as Lucite, Perspex, and Plexiglas; (also) polymerized methyl methacrylate.

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the world > matter > chemistry > organic chemistry > esters > [noun] > named

oxalic ether1788

margarate1819

acrylate1843

urethane1856

tropeine1880

malonic ester1881

heavy oil of wine1882

phosphatide1884

ethanoate1892

imino-ester1897

acetylcholine1906

phaeophytin1907

phytic acid1908

propiolactone1917

silicon ester1923

methyl methacrylate1933

Tylose1934

testosterone propionate1937

filicin1941

trichothecin1948

siphonein1949

acetyl coenzyme A1950

acetyl CoA1951

society > occupation and work > materials > derived or manufactured material > synthetic resins and plastics > [noun] > plastic > capable of hardening after heating or (re)shaping > solid transparent

methyl methacrylate1933

Perspex1935

Plexiglas1935

Lucite1937

1933 Chem. Abstr. 27 4363 Thermoplastic products are obtained by polymerizing methyl methacrylate..by exposure to light or heat.

1936 Industr. & Engin. Chem. Oct. 1161/2 These properties make methyl methacrylate an outstanding plastic.

1964 N. G. Clark Mod. Org. Chem. x. 194 Acetone cyanohydrin..is an important intermediate in the manufacture of methyl methacrylate, the material used for making the polymer ‘Perspex’.

1987 E. W. Burr Compan. Bird Med. xxiv. 161/1 Methyl methacrylate has been used to stabilize avian fractures.

1993 ICI Ann. Rep. 1992 14/2 ICI Acrylics commissioned a large new methyl methacrylate (MMA) plant in the UK.

methyl orange n. an orange crystalline dye that is the sodium salt of the azo compound of dimethylaniline and sulphanilic acid and is chiefly used as an acid–base indicator, changing from red to yellow-orange over a pH range of 3.1 to 4.4; (CH₃)₂NC₆H₄N=NC₆H₄SO₃Na.

ΘΚΠ

the world > matter > chemistry > chemical tests > indicators > [noun] > pH indicators > acid or base indicators

methyl orange1881

neutral red1890

methyl red1910

1881 G. Lunge in Chem. News 16 Dec. 288/1 It is in reality a salt of sulpho-benzene-azo-dimethylamin, for which long name I propose the short and sufficiently clear name ‘Methyl-orange’.

1910 Jrnl. Chem. Soc. 97 2490 Methyl-orange cannot be used when conc. H· is greater than 10⁻⁵.

1930 S. Field & A. D. Weill Electro-plating 56 The ordinary indicators used by the chemist such as litmus, methyl orange and phenolphthalein.

1969 H. A. Flaschka et al. Quantitative Analyt. Chem. II. ix. 110 Methyl orange is therefore unsuited to the titration of a weak acid.

1989 R. Dryer & G. Lata Exper. Biochem. ii. i. 341 Many dyes are noncovalently bound to proteins. Methyl orange, phenolphthalin..are examples.

methylpentynol n. Pharmacology the compound 3-methylpent-1-yn-3-ol, C₆H₁₀O, used (now rarely) as an oral sedative and hypnotic.

ΚΠ

1953 Brit. Med. Jrnl. 22 Aug. 435/2 About two years ago Margolin and his colleagues described the hypnotic properties of 3-methyl-pentyne-ol-3... Methylpentynol, as it is called (or methyl parafynol), is unlike methyl alcohol in that it does not cause intoxication, but when administered to animals or man it sends them to sleep.

1968 J. H. Burn Lect. Notes Pharmacol. (ed. 9) 58 Methylpentynol (Oblivon) reduces apprehension in those about to visit the dentist.

1986 Jrnl. Neurol., Neurosurg. & Psychiatry 49 198 Six patients with essential tremor tested in the therapeutic effectiveness of a 6-carbon alcohol, methylpentynol,..against placebo in a randomised double-blind clinical cross-over trial.

methylphenidate n. Pharmacology a central nervous system stimulant with effects similar to those of dexamphetamine, used (as the hydrochloride) in the treatment of narcolepsy and as an adjunct in the treatment of attention deficit disorder in children; methyl α-phenyl-α-(2-piperidyl)acetate, C₁₄H₁₉NO₂; cf. Ritalin n.

ΚΠ

1956 Jrnl. Amer. Med. Assoc. 1 Dec. 1304/1 This prompted us to try a course of therapy with methylphenidate parenteral solution on a group of chronically regressed, underactive patients.

1976 Primary Care 3 609 The current treatments of choice [for narcolepsy] are methylphenidate (for sleepiness and sleep episodes) and imipramine (for cataplexy).

1994 Guardian 7 Sept. i. 11/7 The main boost came from spectacular growth in sales of Methylphenidate, a drug to combat hyperactivity in children.

methylprednisolone n. a synthetic glucocorticoid, C₂₂H₃₀O₅, used chiefly in the treatment of inflammatory and autoimmune disorders.

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the world > health and disease > healing > medicines or physic > medicines for specific purpose > preparations treating or preventing specific ailments > [noun] > for arthritis, rheumatism, or gout > synthetic or biological

pregnenolone1936

methylprednisolone1957

nabumetone1980

1957 Ann. Rheumatic Dis. 16 298/2 6-Methyl-prednisolone was administered under various conditions to 41 patients with active peripheral rheumatoid arthritis.

1960 Antibiotic Med. 7 704 The subcutaneous injection of depot methyl prednisolone has demonstrated significant permanent relief of refractory anal pruritus in 14 patients.

1973 Jrnl. Amer. Med. Assoc. 19 Feb. 896/1 Large doses of methylprednisolone were used intravenously as the sole steroid agent in 44 transplants.

1989 Brain 112 1061 [Two patients] were given high doses of methyl prednisolone intravenously..in an attempt to modify the disease.

2000 Cardiovascular Res. 46 316 Low-dose aspirin reduced perivascular but not interstitial collagen whereas methylprednisolone decreased both perivascular and interstitial collagen.

methyl red n. [ < methyl n. + red n., after German Methylrot (Rupp & Loose 1909, in Bericht der Deutsch. Chem. Ges. 41 3905)] a dark red, weakly acidic, water-insoluble dye that is the azo compound of dimethylaniline and anthranilic acid and is used (in alcoholic solution) as an acid–base indicator, changing from red to yellow over a pH range of 4.2 to 6.3; (CH₃)₂NC₆H₄N=NC₆H₄COOH.

ΘΚΠ

the world > matter > chemistry > chemical tests > indicators > [noun] > pH indicators > acid or base indicators

methyl orange1881

neutral red1890

methyl red1910

1910 Jrnl. Chem. Soc. 97 2490 As a means of measuring colorimetrically the concentration of hydrogen ions in a solution, methyl-red would probably be found valuable when such concentration lies between 10⁻⁵ and 10⁻⁶.

1933 S. W. Cole Pract. Physiol. Chem. (ed. 9) xiv. 331 Wash down the exterior of D also, add a few drops of methyl-red..and titrate with the CO₂-free soda.

1969 R. B. Fischer & D. G. Peters Brief Introd. Quantitative Chem. Anal. viii. 212 At pH 4·2 (and below)..methyl red is present as the red acid form and..it exists as the yellow base form if the pH becomes 6·2 (and above).

1982 G. C. Hill & J. S. Holman Chem. in Context: Lab. Man. & Study Guide 51/2 Each pair of students will need..Methyl red indicator (28 drops).

methyl rubber n. now historical an early synthetic rubber made by polymerization of dimethylbutadiene.

ΘΚΠ

the world > matter > chemistry > polymer chemistry > rubbers (named) > [noun]

ebonite1861

factice1893

methyl rubber1919

chloroprene1931

polychloroprene1931

polyisobutylene1931

polybutadiene1935

polyisoprene1935

neoprene1937

polyesteramide1943

polydiene1946

Silastic1946

society > occupation and work > materials > derived or manufactured material > synthetic resins and plastics > [noun] > synthetic rubber > specific

methyl rubber1919

Thiokol1930

polychloroprene1931

polyisobutylene1931

polybutadiene1935

polyisoprene1935

polysulphide1935

Buna1936

neoprene1937

Perbunan1938

butyl rubber1940

camel-back1942

polyesteramide1943

polydiene1946

nitrile rubber1947

cold rubber1948

SBR1956

Spandex1959

nitrile1983

1919 India-Rubber Jrnl. 16 Aug. 18/2 The dye works laid themselves out for the manufacture of large quantities of methyl-rubber hot polymerisation products.

1936 Trans. Faraday Soc. 32 91 The sharpness of the fibre pattern depends on the sample of methyl rubber investigated.

1972 Materials & Technol. V. xiv. 456 During the first World War the Germans worked out..the first factory-scale synthetic rubber plant which produced the so-called methyl rubber... The quality of this rubber was poor; it was only useful for the preparation of hard rubber battery boxes for submarines.

methyl salicylate n. the methyl ester of salicylic acid, C₆H₄(OH)COOCH₃, a colourless to pale-yellow liquid that is the chief constituent of oil of wintergreen and is used in perfumes, as a flavouring, and in analgesic liniments.

ΘΚΠ

the world > matter > chemistry > organic chemistry > substances from oils and fats > [noun]

odorine1833

olein1838

palmitin1841

sericin1841

valerol1845

fuscin1864

safrole1869

anethene1872

methyl salicylate1876

salviol1877

isoeugenol1883

cineole1885

citronellal1890

coriandrol1891

tansy oil1894

arachin1905

ascaridol1908

phorbol1935

1876 Encycl. Brit. V. 572/2 Oil of wintergreen..contains methyl salicylate.

1948 Jrnl. Amer. Med. Assoc. 28 Feb. 651/2 Methyl salicylate is a potent and fairly rapidly acting poison.

1972 Materials & Technol. IV. xii. 448 Methyl salicylate, which is a known anti-rheumaticum, is made by the Fischer esterification of salicylic acid.

1994 Healthwatch Mag. Summer 60/1 If you are allergic to ASA, avoid a possible skin reaction by not using topical liniment creams that contain methyl salicylate.

methyltestosterone n. Pharmacology (more fully 17α-methyltestosterone) a synthetic androgen with effects and uses similar to those of testosterone; C₂₀H₃₀O₂.

ΘΚΠ

the world > health and disease > healing > medicines or physic > medical preparations of specific origin > hormones and substances with same effect > [noun]

epinephrine1899

pituitrin1909

oxytocin1927

Pitocin1929

Pitressin1929

progestin1930

progesterone1935

methyltestosterone1936

pregnenolone1936

hexœstrol1939

stilboestrol1939

hydroxyprogesterone1941

progestogen1941

Premarin1942

hydroxycorticosterone1943

gestagen1948

hydrocortisone1951

cortisol1953

fluorohydrocortisone1954

isophane1954

prednisolone1955

prednisone1955

norethisterone1956

norethynodrel1957

dexamethasone1958

fludrocortisone1958

norethindrone1960

antidiuretic hormone1961

medroxyprogesterone1962

Pergonal1963

mesterolone1965

norgestrel1966

quinestrol1966

pancuronium1967

pentagastrin1967

levonorgestrel1977

1936 Biochem. Jrnl. 30 292 Various..derivatives methylated at position 17, including methyltestosterone.

1955 W. Gaddis Recognitions ii. v. 526 Crossing the Atlantic Ocean to get laid. He can't even get it up without a dose of methyltestosterone.

1974 Nature 13 Dec. 585/2 We have induced reversible infertility, with little effect on libido, in five healthy young men by giving them tablets containing methyltestosterone and ethynyloestradiol.

1981 M. C. Gerald Pharmacol. (ed. 2) xxiii. 468 Whereas testosterone and methyltestosterone have approximately equivalent androgenic..and anabolic..effects, the anabolic steroids possess two to three times more of the latter activity.

1999 Newsweek 15 Feb. 53/3 (caption) Barnes was banned once before, for two years, in 1989 after testing positive for methyltestosterone.

methylthiophene n. = thiotoluene n. at thio- comb. form 1.

ΚΠ

1884 Jrnl. Chem. Soc. 46 586 Phenanthraquinone yields a violet dye-stuff, C₁₉H₁₂SO, with methylthiophene.

1946 Nature 2 Nov. 631/2 The separation of thiophene and methylthiophene from benzene and toluene is not easy.

1997 Jrnl. Medicinal Chem. 40 3280 The derivatives in which the phenyl ring was replaced by a 3′-substituted phenyl or methylthiophene ring showed potent immunosuppressive activities.

methylthiouracil n. Pharmacology a methyl derivative of thiouracil used to treat hyperthyroidism; 6-methyl-2-thiouracil, C₅H₆N₂OS.

ΘΚΠ

the world > health and disease > healing > medicines or physic > medicines for specific purpose > preparations treating or preventing specific ailments > [noun] > for thyroid conditions

thyro-antitoxin1895

thiouracil1905

propylthiouracil1914

methylthiouracil1944

methimazole1951

thiamazole1971

1944 Q. Jrnl. Pharmacy & Pharmacol. 17 318 Methylthiouracil produces hyperplasia of the thyroid gland of the rat.

1960 Lancet 19 Mar. 653/2 Professor Wayne's references..to methylthiouracil prompt me to record the long-term follow-up of 100 consecutive cases of thyrotoxicoses.

1968 Listener 18 July 70/1 I had recently been diagnosed as hyperthyroidic and had with remarkable benefit embarked on a course of methylthiouracil tablets.

1996 Electrophoresis 17 1959 Capillary zone electrophoresis was optimized for the separation of thiouracil, methylthiouracil and propylthiouracil.

methyl violet n. any of a group of methylated rosaniline dyes that vary in colour from bluish to reddish violet depending on their degree of methylation; cf. gentian violet n. at gentian n. and adj. Compounds 2, crystal violet n. at crystal n. and adj. Compounds 2.

ΘΚΠ

the world > matter > colour > named colours > purple or purpleness > purple dye or pigment > [noun]

turnsole1375

cork1483

jarecork1483

orchil1483

purple1519

purpurisse1519

archil1551

waycoriant1658

orchilla1703

cudbear1772

purple lake1785

imperial purple1788

mauve?1796

phenicin1823

French purple1830

indigo-purple1838

mauve1859

Perkin's mauve1859

violine1859

mauveine1863

purple of Cassiusc1865

tyroline1867

Paris violet1868

Hofmann violet1869

methyl violet1873

punicin1879

crystal violet1885

chrome violet1892

mineral violet1913

Monastral1936

manganese purple1937

1873 Jrnl. Chem. Soc. 26 1272 The products thus obtained..are distinguished by the name ‘methyl violet’.

1891 Standard 2 Feb. 5/2 Experiments with solutions of methyl violet, also called pyoctanine, a new pigment manufactured at Darmstadt.

1922 J. J. Sudborough Bernthsen's Text-bk. Org. Chem. (new ed.) xxx. 517 The methyl-violets..are mixtures of hexa-, penta-, and tetramethyl-rosanilines, and are amorphous.

1972 Acta Pathol. & Microbiol. Scand. A. 80 185 The substance displays some properties similar to those of classic amyloid, such as..responsiveness to methyl-violet, iodine green and Lugol's solution.

1984 M. J. Taussig Processes in Pathol. & Microbiol. (ed. 2) iv. 386 A heat-fixed bacterial smear on a slide is first stained with the basic dye, methyl violet (or crystal violet).

1999 Analyt. Biochem. 268 187 A new quantitative determination method for nucleic acids in aqueous solutions, based on the enhancement of Rayleigh light scattering of methyl violet by nucleic acids, has been developed.

This entry has been updated (OED Third Edition, December 2001; most recently modified version published online March 2022).

单词	methyl
释义	methyln. Brit. /ˈmiːθʌɪl/, /ˈmɛθʌɪl/, /ˈmɛθ(ᵻ)l/, U.S. /ˈmɛθ(ə)l/ Forms: 1800s methule, 1800s methyle, 1800s– methyl. Origin: A borrowing from German. Etymon: German Methyl. Etymology: < German Methyl (F. Wöhler 1836, in Jahres-Bericht über die Fortschritte der physischen Wissensch. 15 381), shortened < Methylen methylene n., after Swedish metyl (Berzelius 1835, in Årsberättelser om vetenskapernas framsteg, afgifne af Kongl. Vetenskaps-Academiens embetsmän 376), itself shortened < metylen methylene n., after etyl ethyl n. (compare -yl suffix). Compare French méthyle ( A. J. L. Jourdan tr. Berzelius Traité de chim. (1839) III. 403). Chemistry. The hydrocarbon radical present in wood spirit (methanol) and its derivatives; the group or radical CH₃—.In earliest use, not clearly distinct from methylene n. ΘΚΠ the world > matter > chemistry > organic chemistry > hydrocarbons > [noun] > hydrocarbon radicals > named, by number of carbon atoms > one methylene1835 methyl1840 methene1867 1840 J. Berzelius in London & Edinb. Philos. Mag. 16 6 For the sake of brevity, E will be = C⁴H¹⁰, ethyle; Me = C²H⁶, methyle; F = C²H², formyle. 1844 G. Fownes Man. Elem. Chem. iv. 416 Compounds of methyle, with fluorine, cyanogen, and sulphur, have also been obtained. 1847 Amer. Jrnl. Sci. 54 333 The same is true of..oxyd of methyle and alcohol. 1849 Jrnl. Chem. Soc. 2 263 The mixture consisted of methyl and the hitherto unisolated radical ethyl. 1879 J. Tyndall Fragm. Sci. (ed. 6) I. xvii. 447 The positions of chloroform and iodide of methyl are inverted. 1929 Chem. Abstr. 23 5159 It is concluded..that the reactive substance in all these expts. is free methyl. 1957 Ann. Rev. Biochem. 26 451 The methyl group can be derived from acetate methyl. 1974 Chem. in Brit. (Royal Soc. Chem.) 10 54/1 The methyl goes on to the carbon and the charge is neutralized by the nitrogen. 1989 Chem. Senses 14 805 Modification or substitution of the guanidin[i]um group by other basic groups including amine, methyl or dimethylamine..resulted in loss of stimulatory ability. Compounds C1. General attributive and appositive, esp. in methyl group, methyl radical. ΚΠ 1844 G. Fownes Man. Elem. Chem. Index Methyle-compounds. 1861 Jrnl. Chem. Soc. 13 323 In exceptional cases only have I worked in the methyl-series. 1883 Science 23 Feb. 75/1 By heating xanthine-silver [i.e. the silver compound of xanthine] with methyl iodide, a methyl group was introduced. 1899 T. C. Allbutt et al. Syst. Med. VIII. 577 [Cacodylic acid] is a combination of arsenic with methyl radicals. 1922 J. J. Sudborough Bernthsen's Text-bk. Org. Chem. (new ed.) xl. 598 Codeine..is a methyl derivative of morphine. 1926 J. Read Text-bk. Org. Chem. xi. 203 By replacing six hydrogen atoms in the molecule of the magenta dye, pararosaniline, with six methyl groups,..is produced. 1951 Jrnl. Biol. Chem. 189 203 Methionine is the methyl donor for the methylation of both nicotinamide and guanidoacetic acid. 1955 B. C. L. Kemp Elem. Org. Chem. (new ed.) xxiv. 306 Salicylic Acid, 1 : 2 C₆H₄(OH)COOH, occurs naturally in the form of its methyl ester, which is the main constituent of oil of wintergreen. 1962 J. T. Marsh Self-smoothing Fabrics xviii. 300 Free methyl radicals might possibly react with the quinoid group..and produce a methoxyl group which would destroy the chromophoric structure. 1965 J. R. Dyer Applic. Absorption Spectroscopy Org. Compounds iv. 66 Under higher resolution the peaks of ethyl alcohol..attributed to methylene and methyl protons appear as multiplets. 1967 Experientia 23 793/1 We..wish to report the isolation of picene and chrysene, along with evidence that methyl homologs of these are also present. 1985 P. J. Wingate Before Bridge xx. 200 Then he gave me the job of learning how to insert an angular methyl group into the napthalene molecule. 1991 Economist 13 July 105/2 One way to turn genes off is to plaster molecules called methyl groups all over the DNA from which the gene is made. 2000 Biochem. Jrnl. 346 475 Methionine adenosyltransferase is an essential cellular enzyme which catalyses the formation of S-adenosylmethionine, the principal methyl donor and precursor for polyamines. C2. Forming the systematic, semi-systematic, or trivial names of organic compounds containing one or more methyl groups.Also with locant.In systematic substitution nomenclature methyl is now normally written as one word with the item to which it is prefixed. Two-word names are used chiefly in functional class nomenclature, where the second (or final) word is a class term, as of an acid or acid derivative, oxygen or carbonyl compound, halide or pseudohalide, etc. In later systematic use, therefore, there is usually a semantic difference between the two forms, as between methyl malonate (the dimethyl ester of malonic acid) and methylmalonate (a salt or ester of methylmalonic acid), although this rule of chemical nomenclature is not always applied consistently. a. spec. prefixed to the name of a parent compound to indicate substitution of a methyl group for a hydrogen atom or other substituent, as methylacetophenone, methyl-codeia, etc. ΚΠ 1850 C. G. B. Daubeny Introd. Atomic Theory (ed. 2) viii. 240 Methylaniline, where the second atom is replaced by methyle instead of ethyle. 1866 W. Odling Lect. Animal Chem. 45 Leave the urea and methylamine residues combined with one another in the form of methyl-uramine or methyl-guanidine. 1868 Rep. Brit. Assoc., Sections 38 Iodide of methylacetonamine. 1874 A. B. Garrod & E. B. Baxter Essentials Materia Medica (ed. 4) 201 The hypnotic effect of codeia is wholly destroyed by its conversion into methyl-codeia. 1885 I. Remsen Introd. Study Compounds of Carbon (1888) 357 Methyl-sulphonic acid..methyl-carbonic or acetic acid. 1934 C. C. Steele Introd. Plant Biochem. xxi. 237 The terpenes and camphors are derived from p-methyl-isopropyl-cyclohexane, C₁₀H₂₀, known as menthane. 1964 N. G. Clark Mod. Org. Chem. xxiii. 479 The ketones are frequently employed..as ingredients in perfumery. Some simple derivatives possess quite delightful odours, for example, p-methylacetophenone (hawthorn). b. spec. forming the names of organometallic compounds in which the metal is bound to the carbon atom of a methyl group, as methylcopper, methyl-lithium, methyl-tin, etc. Cf. methide n. 1. ΚΠ 1850 Q. Jrnl. Chem. Soc. 2 298 It is highly probable that this body, which for the present I propose to call Zincmethyl, plays the part of a radical.] 1920 Chem. News 120 229/1 It is found that methyl tin trichloride forms double salts with various amine hydrochlorides. 1935 Jrnl. Amer. Chem. Soc. 57 1063/1 Methylmagnesium chloride. 1952 Jrnl. Org. Chem. 17 1630 The cuprous chloride then reacted with more of the Grignard reagent or organolithium compound to give a bright yellow, ether-insoluble methylcopper compound. 1965 Steroids 6 111 (title) The reaction of 3-alpha-acetoxy-4-alpha, 5-alpha-epoxy-cholestane (I) with methyllithium and with methylmagnesium iodide. 1979 Analyt. Chem. 51 12 (title) Separation and determination of nanogram amounts of inorganic tin and methyltin compounds in the environment. 1981 Proc. National Acad. Sci. U.S.A. 78 1318/2 The methylrhodium complex [μCH₃Rh(1,5-cyclooctadiene)]₂ was obtained in high yield from methyllithium and the chlororhodium cyclooctadiene dimer. 1991 Science 252 1267/2 The best description of methyllithium is CH₃⁻Li⁺ with little covalent character. 1996 Chemosphere 32 1983 Organotin compounds, mainly methyltin and butyltin.., were detected in distributed water samples from six municipalities. C3. methyl alcohol n. = methanol n. ΚΠ 1847 Amer. Jrnl. Sci. 54 333 Methyl alcohol. 1872 Jrnl. Chem. Soc. 25 234 (heading) Reduction of formic acid to formaldehyde and methyl alcohol. 1922 Jrnl. Chem. Soc. A. 122 i. 47 Ergotamine, obtained in crystallisable form from ergot, on treatment with methyl alcohol gives a new, less active alkaloid, ergotaminine. 1946 Nature 26 Oct. 592/2 The increased ionicity of the C—O bond in ethyl alcohol relative to C—O in methyl alcohol. 1968 Brain 91 220 Illicit gin known to contain a high concentration of methyl alcohol is consumed in large quantities in the coastal areas. 1991 South Aug. 58/2 Bio-diesel is made by mixing rape seed oil..with Methyl Alcohol to produce Methyl RSO. methyl bromide n. a highly toxic gas, CH₃Br, which is liquid below 3°C and is used in organic synthesis and as a fumigant; also called bromomethane. ΚΠ 1850 Philos. Trans. (Royal Soc.) 140 113 Bromide of methyl.] 1871 Proc. Royal Soc. 1870–71 19 504 When..the action of hydrobromic acid [on codeia] is prolonged, methyl bromide is evolved in some little quantity. 1929 Jrnl. Amer. Chem. Soc. 51 2535 We have found methyl bromide to be a satisfactory methylating agent. 1948 New Biol. 4 71 The most common fumigants in use in this country are..methyl bromide, [etc.]. 1990 C. Rose Dirty Man of Europe (1991) x. 245 She has been experiencing ‘general weakness, giddiness, numbness and shudderings’ after working in a field fumigated with methyl bromide. methyl chloride n. a gas, CH₃Cl, which is liquid below 12°C and is used as a refrigerant; also called chloromethane. ΚΠ 1849 Philos. Trans. (Royal Soc.) 139 381 The time of air was 973, 973 seconds; of chloride of methyl, 592, 587 and 582 seconds.] 1872 Proc. Royal Soc. 1871–2 20 282 No perceptible evolution of methyl chloride took place. 1945 Soap & Sanitary Chemicals Apr. 125/3 Methyl chloride is an excellent propellant gas for aerosols to be used against insects out of doors. 1990 Science 249 160/1 The most abundant halohydrocarbon species in the upper atmosphere is methyl chloride. methylchloroform n. a non-flammable toxic volatile liquid, CH₃CCl₃, used as a solvent, an aerosol propellant, and for metal degreasing; 1,1,1-trichloroethane. ΚΠ 1888 Jrnl. Chem. Soc. 54 841 Ethylenediphenylsulphone is the chief product obtained when methylchloroform is heated with sodium benzenesulphinate. 1969 Arch. Environmental Health 19 467 Methyl chloroform can be specifically detected in a peripheral blood sample of an exposed individual. 1990 Sci. News 28 July 62/1 Used by many industries as an electronics solvent, methylchloroform depletes the ozone layer and contributes to global warming. methylcholanthrene n. [after German Methyl-cholanthren (H. Wieland & E. Dane 1933, in Zeitschr. f. Physiol. Chem. 219 241)] a highly mutagenic and carcinogenic polycyclic hydrocarbon, C₂₁H₁₆, which is widely used in cancer research. ΚΠ 1933 Chem. & Industry 11 758/2 In our selenium dehydrogenation experiment we obtained..a yellow hydrocarbon, evidently identical with the ‘methylcholanthrene’ of Wieland and Dane. 1984 M. J. Taussig Processes in Pathol. & Microbiol. (ed. 2) vi. 768 A two-stage process can be shown to be involved in induction of malignant neoplasms: for example, sesame seed oil injections promote the development of sarcomas in rats after feeding methylcholanthrene. methyl cyanide n. (a) = methyl isocyanide n. (now rare); (b) = acetonitrile n. ΚΠ 1856 Philos. Trans. (Royal Soc.) 146 453 Acetonitrile, or Cyanide of Methyl.] 1871 H. E. Roscoe Lessons Elem. Chem. (new ed.) xxix. 320 The cyanogen is connected with the methyl by the atom of nitrogen, and this body is therefore called methyl cyanide. The other isomer has been called Acetonitril. 1877 H. Watts Fownes's Man. Chem. (ed. 12) II. 92 Methyl cyanide, Ethenyl-nitril or Acetonitril, boils at 77°. 1906 H. F. Morley & M. M. P. Muir Watts' Dict. Chem. III. 305/2 Methyl cyanides, acetonitrile and methyl carbamate. 1964 N. G. Clark Mod. Org. Chem. xiii. 259 The cyanides (nitriles) form a homologous series of the general formula C_nH_2n+1.CN... The simplest method of naming these compounds is to call them alkyl cyanides, so that the first member of the series is methyl cyanide, CH₃.CN. 1980 Proc. Royal Soc. A. 370 241 (caption) Detection of the heterodimer formed between methyl cyanide and hydrogen fluoride by means of its gas-phase rotational spectrum. 5-methylcytosine n. a methylated form of the pyrimidine base cytosine that is involved in the control of transcription in eukaryotes. ΚΠ 1903 Amer. Chem. Jrnl. 29 495 The natural assumption is that the analogous thymine..results from the decomposition of a corresponding base, the as yet undiscovered 5-methylcytosine. 1989 B. Alberts et al. Molecular Biol. Cell (ed. 2) x. 583 Vertebrate DNAs contain 5-methylcytosine.., which has the same relation to cytosine that thymine has to uracil and likewise has no effect on base-pairing. 2000 Mutation Res. 462 137 Thymine produced at these sites by the hydrolytic deamination of 5-methylcytosine is removed by thymine-DNA glycosylase. methyldopa n. Pharmacology (more fully alpha-methyldopa) the compound 3-(3,4-dihydroxyphenyl)-2-methyl-L-alanine, C₁₀H₁₃NO₄, which is used as an antihypertensive agent. ΘΚΠ the world > health and disease > healing > medicines or physic > medicines for specific purpose > preparations treating or preventing specific ailments > [noun] > for blood-pressure disorders Neo-Synephrine1934 Priscol1938 phenylephrine1947 hexamethonium1949 Priscoline1949 methonium1950 hydralazine1952 phentolamine1953 methyldopa1954 pentolinium1954 mecamylamine1955 hydrochlorothiazide1958 pempidine1958 guanethidine1959 hydroflumethiazide1959 thiazide1959 pheniprazine1960 pargyline1961 vasodepressor1961 alpha blocker1965 clonidine1969 prazosin1970 timolol1973 1954 Arch. Biochem. & Biophysics 51 456 Two compounds, α-methyl-3,4-dopa (α-MD) and α-methyl-3-hydroxyphenylalanine, respectively, added in a low range of concentrations, accelerated, and at higher concentrations, inhibited, kidney dopa decarboxylase. 1961 N.Z. Med. Jrnl. 60 569/2 Methyl dopa, like other potent hypotensive agents, produces side-effects including fatigue. 1972 Materials & Technol. V. xxi. 792 Methyldopa and pargyline cause the replacement of noradrenaline by a weaker transmitter. 1984 M. J. Taussig Processes in Pathol. & Microbiol. (ed. 2) ii. 92 For instance, α-methyldopa, a drug used in treatment of hypertension, induces autoimmune haemolytic anaemia. 2000 S. Afr. Med. Jrnl. 90 156 Methyldopa was the antihypertensive used most frequently for the treatment of mild to moderate hypertension. methyl ether n. (a) dimethyl ether, (CH₃)₂O; (b) any ether in which one of the groups attached to the oxygen atom is a methyl group. ΚΠ 1852 H. Watts tr. L. Gmelin Hand-bk. Chem. VII. 257 Methyl-ether gas..burns with a flame like that of alcohol. 1854 J. Scoffern in Orr's Circle Sci., Chem. 109 Butyric ether and butyric methyl ether. 1926 H. G. Rule tr. J. Schmidt Text-bk. Org. Chem. 119 Methyl ether, CH₃.O.CH₃, is obtained even more readily under these conditions. 1931 Jrnl. Chem. Soc. 273 The Friedel-Crafts reaction has now been extended to the coupling of malonyl chloride..with methyl ethers of resorcinol. 1967 I. L. Finar Org. Chem. (ed. 5) I. vii. 166 Dimethyl ether (methyl ether) is prepared industrially by passing methanol vapour at 350–400°, and at a pressure of 15 atmospheres, over aluminium phosphate as a catalyst. 1996 Proc. National Acad. Sci. U.S.A. 93 12828/1 MMAS-3 O-methylates this secondary alcohol to form the corresponding methyl ether. methyl ethyl ketone n. butanone, CH₃CH₂COCH₃; abbreviated MEK. ΘΚΠ the world > matter > chemistry > organic chemistry > ketones > [noun] > used as solvents mesityl oxide1868 methyl ethyl ketone1876 methyl isobutyl ketone1888 MEK1930 hexone1938 1876 Jrnl. Chem. Soc. 29 897 By the reduction of methyl-ethyl ketone, pinacone C₈H₁₈O is obtained. 1938 H. P. Starck Princ. Org. Chem. vii. 186 Methyl ethyl ketone was formerly used as a solvent in the preparation of cordite from gun cotton and nitroglycerine. 1959 Times Rev. Industry Aug. 98/1 Methylethylketone for removing waxy materials. 1992 Earth Matters Autumn 2/1 Two plants..are releasing more of the toxic chemicals xylene, benzene and methyl ethyl ketone to water than 26,000 US firms combined! methylglyoxal n. a toxic aldehyde, CH₃COCHO, which occurs naturally as a by-product of carbohydrate metabolism. ΘΚΠ the world > matter > chemistry > organic chemistry > aldehydes or alkanals > [noun] > miscellaneous named aldehydes > others acrolein1841 metaldehyde1841 trichlorocetaldehyde1845 valeral1852 toluic aldehyde1857 glyoxal1858 acraldehyde1864 propionic aldehyde1866 lauric aldehyde, ether1868 salicylaldehyde1869 dialdane1876 isovaleraldehyde1883 rhodinal1892 propenal1894 oxaldehyde1895 methylglyoxal1898 hadromal1899 malondialdehyde1904 pyruvic aldehyde1909 trioxan1915 plasmal1925 1898 Jrnl. Chem. Soc. 74 i. 224 Methylglyoxal is formed from dihydroxyacetone..when the latter is distilled with dilute sulphuric acid. 1913 Jrnl. Biol. Chem. 14 423 The catalyst..effects the rapid conversion of methyl glyoxal into lactic acid. 1951 Jrnl. Biol. Chem. 190 685 The first step consists in a condensation reaction between methylglyoxal and glutathione catalyzed by an enzyme referred to in this paper as glyoxalase I. 1962 A. Pirie Lens Metabolism 431 Experiments were done in the hope of detecting methylglyoxal which Salem and Crooke (1950) stated was formed from hexosediphosphate by liver. 1991 Jrnl. Agric. & Food Chem. 39 2231/1 The interaction of several labile coffee constituents including aliphatic dicarbonyl compounds, e.g., methylglyoxal. methyl green n. a green dye of the triphenylmethane series, C₂₇H₃₅BrClN₃, used especially as a histological stain and indicator for DNA. ΘΚΠ the world > matter > colour > named colours > green or greenness > green colouring matter > [noun] > pigment or dye > dyes and dyestuffs greening worta1200 greening weeda1399 spinach-green1845 emeraldine1864 methyl green1873 malachite green1875 viridine1875 1873 Jrnl. Chem. Soc. 26 1272 Another methyl group may be added by the action of methyl chloride on methyl violet, forming the compound known as ‘methyl green’. 1906 Practitioner Nov. 666 Stained with pyronin and methyl green, the nuclei were large, rounded, pale, and contained chromatin. 1922 J. J. Sudborough Bernthsen's Text-bk. Org. Chem. (new ed.) xxx. 517 Such additions cause a change of colour from violet to green; thus the compound [formula] is the dye methyl green or light green. 1973 R. G. Krueger et al. Introd. Microbiol. v. 188/2 The cell wall can be visualised..by treatment of the cell with specific cell wall stains, such as phosphomolybdic acid and methyl green. 1994 Denver Post 30 Jan. t1/3 All the new electrochemical pastels..demure, Congo ruby, methyl green, [etc.]. methyl isobutyl ketone n. a liquid ketone, (CH₃)₂CHCH₂COCH₃, which is manufactured by the hydrogenation of mesityl oxide and widely used as a solvent; 4-methylpentan-2-one; cf. hexone n. 2. ΘΚΠ the world > matter > chemistry > organic chemistry > ketones > [noun] > used as solvents mesityl oxide1868 methyl ethyl ketone1876 methyl isobutyl ketone1888 MEK1930 hexone1938 1888 Jrnl. Chem. Soc. 54 125 Its ketone..is therefore identical with methyl isobutyl ketone. 1960 Times Rev. Industry Dec. 16/3 The chloride is dissolved in water, and then treated with an organic solvent called methylisobutyl ketone (MIBK) which extracts the iron. 1973 H. M. Stanley in E. G. Hancock Propylene i. 9 The Shell Oil Company..in 1937–8 commenced the manufacture of acetone derivatives, including diacetone alcohol, mesityl oxide and methylisobutyl ketone. methyl isocyanate n. a highly toxic volatile liquid, CH₃NCO, used in the manufacture of insecticides and herbicides. ΚΠ 1894 G. M'Gowan tr. A. Bernthsen Text-bk. Org. Chem. (ed. 2) 121 Methylamine, ethylamine, etc., are obtained by treating methyl or ethyl etc. iso-cyanate with potash solution. 1985 Listener 6 June 7/1 Workers at the plant used to refer jokingly to the methyl isocyanate (MIC) used to make pesticides as ‘lions that could gobble up the people of Bhopal’. methyl isocyanide n. a toxic liquid, CH₃NC. ΚΠ 1889 G. M'Gowan tr. A. Bernthsen Text-bk. Org. Chem. 110 Methyl iso-cyanide, CH₃.NC.B.Pt. 58°. 1966 New Statesman 2 Dec. 826/2 Methyl isocyanide..is chemically very like nitrogen yet much easier to work with. † methyl malonate n. Obsolete rare the dimethyl ester of malonic acid, C₅H₈O₄. ΚΠ 1875 Jrnl. Chem. Soc. 28 142 Methyl malonate, C₃H₂(CH₂)₂O₄, which was obtained by treating the silver-salt with methyl iodide, is a mobile liquid bearing an ethereal smell, and boiling at 175°–180°. methyl mercaptan n. a flammable gas with a pungent odour, CH₃SH, which is used as an organic reagent and in the manufacture of jet fuels and pesticides. ΚΠ 1844 G. Fownes Man. Elem. Chem. 420 Methyl-mercaptan..is a colourless liquid, of powerful alliaceous odour. 1962 Which? Mar. 91/1 Our final choice was methyl mercaptan, which smells like boiled cabbage and is a constituent of the smell of drains. 1997 New Scientist 26 July 37/2 If a wine has too much methyl mercaptan in it, you think of burning rubber. methylmercury n. (a) a highly toxic cation, CH₃Hg⁺, compounds of which were formerly used as seed disinfectants, and which may be synthesized in the environment by microbial methylation of inorganic mercury compounds; (b) the toxic liquid dimethylmercury, (CH₃)₂Hg (rare). ΘΚΠ the world > matter > chemistry > elements and compounds > metals > specific elements > mercury > [noun] > compounds sublimate1543 precipitate1563 red mercury1582 quicksilver extinct1610 red precipitate1676 mercury fulminate1904 methylmercury1915 mercurochrome1919 mercurial1971 1915 P. E. Spielmann tr. V. von Richter Org. Chem. 188 Silver nitrate changes it to methyl mercury nitrate, CH₃Hg.ONO₂. 1935 Jrnl. Agric. Sci. 25 636 Dusts were prepared with a range of methyl mercury compounds of varying solubilities. 1970 Atlantic Sept. 25 The Swedes solved their problem by banning the use of one extremely pervasive compound, methylmercury, and shipping it to the United States, where it is now used to treat wheat seed. 1981 M. C. Gerald Pharmacol. (ed. 2) xxxi. 605 In 1969, three members of a New Mexican family of nine were poisoned and suffered severe brain damage after eating a hog that was fed on grain containing methylmercury. 1991 Sea Frontiers Mar. 6/1 The behavioral differences between the two groups of cats may be caused by high levels of methylmercury in the tuna [in cat food]. methyl methacrylate n. the methyl ester of methacrylic acid, CH₂=C(CH₃)COOCH₃, which is a volatile liquid that readily polymerizes to form a transparent plastic used as a glass substitute, sold under names such as Lucite, Perspex, and Plexiglas; (also) polymerized methyl methacrylate. ΘΚΠ the world > matter > chemistry > organic chemistry > esters > [noun] > named oxalic ether1788 margarate1819 acrylate1843 urethane1856 tropeine1880 malonic ester1881 heavy oil of wine1882 phosphatide1884 ethanoate1892 imino-ester1897 acetylcholine1906 phaeophytin1907 phytic acid1908 propiolactone1917 silicon ester1923 methyl methacrylate1933 Tylose1934 testosterone propionate1937 filicin1941 trichothecin1948 siphonein1949 acetyl coenzyme A1950 acetyl CoA1951 society > occupation and work > materials > derived or manufactured material > synthetic resins and plastics > [noun] > plastic > capable of hardening after heating or (re)shaping > solid transparent methyl methacrylate1933 Perspex1935 Plexiglas1935 Lucite1937 1933 Chem. Abstr. 27 4363 Thermoplastic products are obtained by polymerizing methyl methacrylate..by exposure to light or heat. 1936 Industr. & Engin. Chem. Oct. 1161/2 These properties make methyl methacrylate an outstanding plastic. 1964 N. G. Clark Mod. Org. Chem. x. 194 Acetone cyanohydrin..is an important intermediate in the manufacture of methyl methacrylate, the material used for making the polymer ‘Perspex’. 1987 E. W. Burr Compan. Bird Med. xxiv. 161/1 Methyl methacrylate has been used to stabilize avian fractures. 1993 ICI Ann. Rep. 1992 14/2 ICI Acrylics commissioned a large new methyl methacrylate (MMA) plant in the UK. methyl orange n. an orange crystalline dye that is the sodium salt of the azo compound of dimethylaniline and sulphanilic acid and is chiefly used as an acid–base indicator, changing from red to yellow-orange over a pH range of 3.1 to 4.4; (CH₃)₂NC₆H₄N=NC₆H₄SO₃Na. ΘΚΠ the world > matter > chemistry > chemical tests > indicators > [noun] > pH indicators > acid or base indicators methyl orange1881 neutral red1890 methyl red1910 1881 G. Lunge in Chem. News 16 Dec. 288/1 It is in reality a salt of sulpho-benzene-azo-dimethylamin, for which long name I propose the short and sufficiently clear name ‘Methyl-orange’. 1910 Jrnl. Chem. Soc. 97 2490 Methyl-orange cannot be used when conc. H· is greater than 10⁻⁵. 1930 S. Field & A. D. Weill Electro-plating 56 The ordinary indicators used by the chemist such as litmus, methyl orange and phenolphthalein. 1969 H. A. Flaschka et al. Quantitative Analyt. Chem. II. ix. 110 Methyl orange is therefore unsuited to the titration of a weak acid. 1989 R. Dryer & G. Lata Exper. Biochem. ii. i. 341 Many dyes are noncovalently bound to proteins. Methyl orange, phenolphthalin..are examples. methylpentynol n. Pharmacology the compound 3-methylpent-1-yn-3-ol, C₆H₁₀O, used (now rarely) as an oral sedative and hypnotic. ΚΠ 1953 Brit. Med. Jrnl. 22 Aug. 435/2 About two years ago Margolin and his colleagues described the hypnotic properties of 3-methyl-pentyne-ol-3... Methylpentynol, as it is called (or methyl parafynol), is unlike methyl alcohol in that it does not cause intoxication, but when administered to animals or man it sends them to sleep. 1968 J. H. Burn Lect. Notes Pharmacol. (ed. 9) 58 Methylpentynol (Oblivon) reduces apprehension in those about to visit the dentist. 1986 Jrnl. Neurol., Neurosurg. & Psychiatry 49 198 Six patients with essential tremor tested in the therapeutic effectiveness of a 6-carbon alcohol, methylpentynol,..against placebo in a randomised double-blind clinical cross-over trial. methylphenidate n. Pharmacology a central nervous system stimulant with effects similar to those of dexamphetamine, used (as the hydrochloride) in the treatment of narcolepsy and as an adjunct in the treatment of attention deficit disorder in children; methyl α-phenyl-α-(2-piperidyl)acetate, C₁₄H₁₉NO₂; cf. Ritalin n. ΚΠ 1956 Jrnl. Amer. Med. Assoc. 1 Dec. 1304/1 This prompted us to try a course of therapy with methylphenidate parenteral solution on a group of chronically regressed, underactive patients. 1976 Primary Care 3 609 The current treatments of choice [for narcolepsy] are methylphenidate (for sleepiness and sleep episodes) and imipramine (for cataplexy). 1994 Guardian 7 Sept. i. 11/7 The main boost came from spectacular growth in sales of Methylphenidate, a drug to combat hyperactivity in children. methylprednisolone n. a synthetic glucocorticoid, C₂₂H₃₀O₅, used chiefly in the treatment of inflammatory and autoimmune disorders. ΘΚΠ the world > health and disease > healing > medicines or physic > medicines for specific purpose > preparations treating or preventing specific ailments > [noun] > for arthritis, rheumatism, or gout > synthetic or biological pregnenolone1936 methylprednisolone1957 nabumetone1980 1957 Ann. Rheumatic Dis. 16 298/2 6-Methyl-prednisolone was administered under various conditions to 41 patients with active peripheral rheumatoid arthritis. 1960 Antibiotic Med. 7 704 The subcutaneous injection of depot methyl prednisolone has demonstrated significant permanent relief of refractory anal pruritus in 14 patients. 1973 Jrnl. Amer. Med. Assoc. 19 Feb. 896/1 Large doses of methylprednisolone were used intravenously as the sole steroid agent in 44 transplants. 1989 Brain 112 1061 [Two patients] were given high doses of methyl prednisolone intravenously..in an attempt to modify the disease. 2000 Cardiovascular Res. 46 316 Low-dose aspirin reduced perivascular but not interstitial collagen whereas methylprednisolone decreased both perivascular and interstitial collagen. methyl red n. [ < methyl n. + red n., after German Methylrot (Rupp & Loose 1909, in Bericht der Deutsch. Chem. Ges. 41 3905)] a dark red, weakly acidic, water-insoluble dye that is the azo compound of dimethylaniline and anthranilic acid and is used (in alcoholic solution) as an acid–base indicator, changing from red to yellow over a pH range of 4.2 to 6.3; (CH₃)₂NC₆H₄N=NC₆H₄COOH. ΘΚΠ the world > matter > chemistry > chemical tests > indicators > [noun] > pH indicators > acid or base indicators methyl orange1881 neutral red1890 methyl red1910 1910 Jrnl. Chem. Soc. 97 2490 As a means of measuring colorimetrically the concentration of hydrogen ions in a solution, methyl-red would probably be found valuable when such concentration lies between 10⁻⁵ and 10⁻⁶. 1933 S. W. Cole Pract. Physiol. Chem. (ed. 9) xiv. 331 Wash down the exterior of D also, add a few drops of methyl-red..and titrate with the CO₂-free soda. 1969 R. B. Fischer & D. G. Peters Brief Introd. Quantitative Chem. Anal. viii. 212 At pH 4·2 (and below)..methyl red is present as the red acid form and..it exists as the yellow base form if the pH becomes 6·2 (and above). 1982 G. C. Hill & J. S. Holman Chem. in Context: Lab. Man. & Study Guide 51/2 Each pair of students will need..Methyl red indicator (28 drops). methyl rubber n. now historical an early synthetic rubber made by polymerization of dimethylbutadiene. ΘΚΠ the world > matter > chemistry > polymer chemistry > rubbers (named) > [noun] ebonite1861 factice1893 methyl rubber1919 chloroprene1931 polychloroprene1931 polyisobutylene1931 polybutadiene1935 polyisoprene1935 neoprene1937 polyesteramide1943 polydiene1946 Silastic1946 society > occupation and work > materials > derived or manufactured material > synthetic resins and plastics > [noun] > synthetic rubber > specific methyl rubber1919 Thiokol1930 polychloroprene1931 polyisobutylene1931 polybutadiene1935 polyisoprene1935 polysulphide1935 Buna1936 neoprene1937 Perbunan1938 butyl rubber1940 camel-back1942 polyesteramide1943 polydiene1946 nitrile rubber1947 cold rubber1948 SBR1956 Spandex1959 nitrile1983 1919 India-Rubber Jrnl. 16 Aug. 18/2 The dye works laid themselves out for the manufacture of large quantities of methyl-rubber hot polymerisation products. 1936 Trans. Faraday Soc. 32 91 The sharpness of the fibre pattern depends on the sample of methyl rubber investigated. 1972 Materials & Technol. V. xiv. 456 During the first World War the Germans worked out..the first factory-scale synthetic rubber plant which produced the so-called methyl rubber... The quality of this rubber was poor; it was only useful for the preparation of hard rubber battery boxes for submarines. methyl salicylate n. the methyl ester of salicylic acid, C₆H₄(OH)COOCH₃, a colourless to pale-yellow liquid that is the chief constituent of oil of wintergreen and is used in perfumes, as a flavouring, and in analgesic liniments. ΘΚΠ the world > matter > chemistry > organic chemistry > substances from oils and fats > [noun] odorine1833 olein1838 palmitin1841 sericin1841 valerol1845 fuscin1864 safrole1869 anethene1872 methyl salicylate1876 salviol1877 isoeugenol1883 cineole1885 citronellal1890 coriandrol1891 tansy oil1894 arachin1905 ascaridol1908 phorbol1935 1876 Encycl. Brit. V. 572/2 Oil of wintergreen..contains methyl salicylate. 1948 Jrnl. Amer. Med. Assoc. 28 Feb. 651/2 Methyl salicylate is a potent and fairly rapidly acting poison. 1972 Materials & Technol. IV. xii. 448 Methyl salicylate, which is a known anti-rheumaticum, is made by the Fischer esterification of salicylic acid. 1994 Healthwatch Mag. Summer 60/1 If you are allergic to ASA, avoid a possible skin reaction by not using topical liniment creams that contain methyl salicylate. methyltestosterone n. Pharmacology (more fully 17α-methyltestosterone) a synthetic androgen with effects and uses similar to those of testosterone; C₂₀H₃₀O₂. ΘΚΠ the world > health and disease > healing > medicines or physic > medical preparations of specific origin > hormones and substances with same effect > [noun] epinephrine1899 pituitrin1909 oxytocin1927 Pitocin1929 Pitressin1929 progestin1930 progesterone1935 methyltestosterone1936 pregnenolone1936 hexœstrol1939 stilboestrol1939 hydroxyprogesterone1941 progestogen1941 Premarin1942 hydroxycorticosterone1943 gestagen1948 hydrocortisone1951 cortisol1953 fluorohydrocortisone1954 isophane1954 prednisolone1955 prednisone1955 norethisterone1956 norethynodrel1957 dexamethasone1958 fludrocortisone1958 norethindrone1960 antidiuretic hormone1961 medroxyprogesterone1962 Pergonal1963 mesterolone1965 norgestrel1966 quinestrol1966 pancuronium1967 pentagastrin1967 levonorgestrel1977 1936 Biochem. Jrnl. 30 292 Various..derivatives methylated at position 17, including methyltestosterone. 1955 W. Gaddis Recognitions ii. v. 526 Crossing the Atlantic Ocean to get laid. He can't even get it up without a dose of methyltestosterone. 1974 Nature 13 Dec. 585/2 We have induced reversible infertility, with little effect on libido, in five healthy young men by giving them tablets containing methyltestosterone and ethynyloestradiol. 1981 M. C. Gerald Pharmacol. (ed. 2) xxiii. 468 Whereas testosterone and methyltestosterone have approximately equivalent androgenic..and anabolic..effects, the anabolic steroids possess two to three times more of the latter activity. 1999 Newsweek 15 Feb. 53/3 (caption) Barnes was banned once before, for two years, in 1989 after testing positive for methyltestosterone. methylthiophene n. = thiotoluene n. at thio- comb. form 1. ΚΠ 1884 Jrnl. Chem. Soc. 46 586 Phenanthraquinone yields a violet dye-stuff, C₁₉H₁₂SO, with methylthiophene. 1946 Nature 2 Nov. 631/2 The separation of thiophene and methylthiophene from benzene and toluene is not easy. 1997 Jrnl. Medicinal Chem. 40 3280 The derivatives in which the phenyl ring was replaced by a 3′-substituted phenyl or methylthiophene ring showed potent immunosuppressive activities. methylthiouracil n. Pharmacology a methyl derivative of thiouracil used to treat hyperthyroidism; 6-methyl-2-thiouracil, C₅H₆N₂OS. ΘΚΠ the world > health and disease > healing > medicines or physic > medicines for specific purpose > preparations treating or preventing specific ailments > [noun] > for thyroid conditions thyro-antitoxin1895 thiouracil1905 propylthiouracil1914 methylthiouracil1944 methimazole1951 thiamazole1971 1944 Q. Jrnl. Pharmacy & Pharmacol. 17 318 Methylthiouracil produces hyperplasia of the thyroid gland of the rat. 1960 Lancet 19 Mar. 653/2 Professor Wayne's references..to methylthiouracil prompt me to record the long-term follow-up of 100 consecutive cases of thyrotoxicoses. 1968 Listener 18 July 70/1 I had recently been diagnosed as hyperthyroidic and had with remarkable benefit embarked on a course of methylthiouracil tablets. 1996 Electrophoresis 17 1959 Capillary zone electrophoresis was optimized for the separation of thiouracil, methylthiouracil and propylthiouracil. methyl violet n. any of a group of methylated rosaniline dyes that vary in colour from bluish to reddish violet depending on their degree of methylation; cf. gentian violet n. at gentian n. and adj. Compounds 2, crystal violet n. at crystal n. and adj. Compounds 2. ΘΚΠ the world > matter > colour > named colours > purple or purpleness > purple dye or pigment > [noun] turnsole1375 cork1483 jarecork1483 orchil1483 purple1519 purpurisse1519 archil1551 waycoriant1658 orchilla1703 cudbear1772 purple lake1785 imperial purple1788 mauve?1796 phenicin1823 French purple1830 indigo-purple1838 mauve1859 Perkin's mauve1859 violine1859 mauveine1863 purple of Cassiusc1865 tyroline1867 Paris violet1868 Hofmann violet1869 methyl violet1873 punicin1879 crystal violet1885 chrome violet1892 mineral violet1913 Monastral1936 manganese purple1937 1873 Jrnl. Chem. Soc. 26 1272 The products thus obtained..are distinguished by the name ‘methyl violet’. 1891 Standard 2 Feb. 5/2 Experiments with solutions of methyl violet, also called pyoctanine, a new pigment manufactured at Darmstadt. 1922 J. J. Sudborough Bernthsen's Text-bk. Org. Chem. (new ed.) xxx. 517 The methyl-violets..are mixtures of hexa-, penta-, and tetramethyl-rosanilines, and are amorphous. 1972 Acta Pathol. & Microbiol. Scand. A. 80 185 The substance displays some properties similar to those of classic amyloid, such as..responsiveness to methyl-violet, iodine green and Lugol's solution. 1984 M. J. Taussig Processes in Pathol. & Microbiol. (ed. 2) iv. 386 A heat-fixed bacterial smear on a slide is first stained with the basic dye, methyl violet (or crystal violet). 1999 Analyt. Biochem. 268 187 A new quantitative determination method for nucleic acids in aqueous solutions, based on the enhancement of Rayleigh light scattering of methyl violet by nucleic acids, has been developed. This entry has been updated (OED Third Edition, December 2001; most recently modified version published online March 2022). < n.1840
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