Methyl group in the context of Demethylated

Methanol (also called methyl alcohol, wood alcohol, and wood spirit, amongst other names) is an organic chemical compound and the simplest aliphatic alcohol, with the chemical formula CH₃OH (a methyl group linked to a hydroxyl group, often abbreviated as MeOH). It is a light, volatile, colorless and flammable liquid with a distinctive alcoholic odor similar to that of ethanol (potable alcohol), but is more acutely toxic than the latter.Methanol acquired the name wood alcohol because it was once produced through destructive distillation of wood. Today, methanol is mainly produced industrially by hydrogenation of carbon monoxide.

Methanol consists of a methyl group linked to a polar hydroxyl group. With more than 20 million tons produced annually, it is used as a precursor to other commodity chemicals, including formaldehyde, acetic acid, methyl tert-butyl ether, methyl benzoate, anisole, peroxyacids, as well as a host of more specialized chemicals.

DNA methylation is a biological process by which methyl groups are added to the DNA molecule. Methylation can change the activity of a DNA segment without changing the sequence. When located in a gene promoter, DNA methylation typically acts to repress gene transcription. In mammals, DNA methylation is essential for normal development and is associated with a number of key processes including genomic imprinting, X-chromosome inactivation, repression of transposable elements, aging, and carcinogenesis.

As of 2016, two nucleobases have been found on which natural, enzymatic DNA methylation takes place: adenine and cytosine. The modified bases are N-methyladenine, 5-methylcytosine and N-methylcytosine.

Toluene (/ˈtɒl.juiːn/), also known as toluol (/ˈtɒl.ju.ɒl, -ɔːl, -oʊl/), is a substituted aromatic hydrocarbon with the chemical formula C₆H₅CH₃, often abbreviated as PhCH₃, where Ph stands for the phenyl group. It is a colorless, water-insoluble liquid with the odor associated with paint thinners. It is a mono-substituted benzene derivative, consisting of a methyl group (CH₃) attached to a phenyl group by a single bond. As such, its systematic IUPAC name is methylbenzene. Toluene is predominantly used as an industrial feedstock and a solvent.

As the solvent in some types of paint thinner, permanent markers, contact cement and certain types of glue, toluene is sometimes used as a recreational inhalant and has the potential of causing severe neurological harm.

In organic chemistry, xylene or xylol (from Greek ξύλον (xylon) 'wood'; IUPAC name: dimethylbenzene) is any of three organic compounds with the formula (CH₃)₂C₆H₄. They are derived from the substitution of two hydrogen atoms with methyl groups in a benzene ring; which hydrogens are substituted determines which of three structural isomers results. It is a colorless, flammable, slightly greasy liquid of great industrial value.

The mixture is referred to as both xylene and, more precisely, xylenes. Mixed xylenes refers to a mixture of the xylenes plus ethylbenzene. The four compounds have identical molecular formulas C₈H₁₀. Typically the four compounds are produced together by various catalytic reforming and pyrolysis methods.

Methylamine, also known as methanamine, is an organic compound with a formula of CH₃NH₂. This colorless gas is a derivative of ammonia, but with one hydrogen atom being replaced by a methyl group. It is the simplest primary amine.

Methylamine is sold as a solution in methanol, ethanol, tetrahydrofuran, or water, or as the anhydrous gas in pressurized metal containers. Industrially, methylamine is transported in its anhydrous form in pressurized railcars and tank trailers. It has a strong odor similar to rotten fish. Methylamine is used as a building block for the synthesis of numerous other commercially available compounds.

Cresols (also known as hydroxytoluene, toluenol, benzol or cresylic acid) are a group of aromatic organic compounds. They are widely-occurring phenols (sometimes called phenolics) which may be either natural or manufactured. They are also categorized as methyl phenols. Cresols commonly occur as either solids or liquids because their melting points are generally close to room temperature. Like other types of phenols, they are slowly oxidized by exposure to air, and the resulting impurities often give the samples a yellow to brownish red tint. Cresols have an odor characteristic to that of other simple phenols, reminiscent to some of a "coal tar" smell. The name "cresol" is an adduct of phenol and their traditional source, creosote.

In organic chemistry, a methoxy group is the functional group consisting of a methyl group bound to oxygen. This alkoxy group has the formula R−O−CH₃.

On a benzene ring, the Hammett equation classifies a methoxy substituent at the para position as an electron-donating group, but as an electron-withdrawing group if at the meta position. At the ortho position, steric effects are likely to cause a significant alteration in the Hammett equation prediction, which otherwise follows the same trend as that of the para position.

Sodium dodecyl sulfate (SDS) or sodium lauryl sulfate (SLS), sometimes written sodium laurilsulfate, is an organic compound with the formula CH₃(CH₂)₁₁OSO₃Na and structure H₃C−(CH₂)₁₁−O−S(=O)₂−ONa. It is an anionic surfactant used in many cleaning and hygiene products. This compound is the sodium salt of the 12-carbon organosulfate. Its hydrocarbon tail combined with a polar "headgroup" give the compound amphiphilic properties that make it useful as a detergent. SDS is also component of mixtures produced from inexpensive coconut and palm oils. SDS is a common component of many domestic cleaning, personal hygiene and cosmetic, pharmaceutical, and food products, as well as of industrial and commercial cleaning and product formulations.

Tocopherols (/toʊˈkɒfəˌrɒl/; TCP) are a class of organic compounds comprising various methylated phenols, many of which have vitamin E activity. Because the vitamin activity was first identified in 1936 from a dietary fertility factor in rats, it was named tocopherol, from Greek τόκος tókos 'birth' and φέρειν phérein 'to bear or carry', that is 'to carry a pregnancy', with the ending -ol signifying its status as a chemical alcohol.

α-Tocopherol is the main source found in supplements and in the European diet, where the main dietary sources are olive and sunflower oils, while γ-tocopherol is the most common form in the American diet due to a higher intake of soybean and corn oil.

Phenylalanine (symbol Phe or F) is an essential α-amino acid with the formula C
₉H
₁₁NO
₂. It can be viewed as a benzyl group substituted for the methyl group of alanine, or a phenyl group in place of a terminal hydrogen of alanine. This essential amino acid is classified as neutral, and nonpolar because of the inert and hydrophobic nature of the benzyl side chain. The L-isomer is used to biochemically form proteins coded for by DNA. Phenylalanine is a precursor for tyrosine, the monoamine neurotransmitters dopamine, norepinephrine (noradrenaline), and epinephrine (adrenaline), and the biological pigment melanin. It is encoded by the messenger RNA codons UUU and UUC.

Phenylalanine is found naturally in the milk of mammals. It is used in the manufacture of food and drink products and sold as a nutritional supplement as it is a direct precursor to the neuromodulator phenethylamine. As an essential amino acid, phenylalanine is not synthesized de novo in humans and other animals, who must ingest phenylalanine or phenylalanine-containing proteins.

Alanine (symbol Ala or A), or α-alanine, is an α-amino acid that is used in the biosynthesis of proteins. It contains an amine group and a carboxylic acid group, both attached to the central carbon atom which also carries a methyl group side chain. Consequently it is classified as a non-polar, aliphatic α-amino acid. Under biological conditions, it exists in its zwitterionic form with its amine group protonated (as −NH+3) and its carboxyl group deprotonated (as −CO−2). It is non-essential to humans as it can be synthesized metabolically and does not need to be present in the diet. It is encoded by all codons starting with GC (GCU, GCC, GCA, and GCG).

The L-isomer of alanine (left-handed) is the one that is incorporated into proteins. L-alanine is second only to L-leucine in rate of occurrence, accounting for 7.8% of the primary structure in a sample of 1,150 proteins. The right-handed form, D-alanine, occurs in peptides in some bacterial cell walls (in peptidoglycan) and in some peptide antibiotics, and occurs in the tissues of many crustaceans and molluscs as an osmolyte.

omega−3 oils, ω−3 fatty acids or n−3 fatty acids, are polyunsaturated fatty acids (PUFAs) characterized by the presence of a double bond three atoms away from the terminal methyl group (numbered ω, the last letter of the Greek alphabet) in their chemical structure. They are widely distributed in nature, are important constituents of animal lipid metabolism, and play an important role in the human diet and in human physiology. The three types of omega−3 fatty acids involved in human physiology are α-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). ALA can be found in plants, while DHA and EPA are found in algae and fish. Marine algae and phytoplankton are primary sources of omega−3 fatty acids. DHA and EPA accumulate in fish that eat these algae. Common sources of plant oils containing ALA include walnuts, edible seeds and flaxseeds as well as hempseed oil, while sources of EPA and DHA include fish and fish oils, and algae oil.

Almost without exception, animals are unable to synthesize the essential omega−3 fatty acid ALA and can only obtain it through diet. However, they can use ALA, when available, to form EPA and DHA, by creating additional double bonds along its carbon chain (desaturation) and extending it (elongation). ALA (18 carbons and 3 double bonds) is used to make EPA (20 carbons and 5 double bonds), which is then used to make DHA (22 carbons and 6 double bonds). The ability to make the longer-chain omega−3 fatty acids from ALA may be impaired in aging. In foods exposed to air, unsaturated fatty acids are vulnerable to oxidation and rancidity.

Cymene describes organic compounds with the formula CH₃C₆H₄CH(CH₃)₂. Three isomers exist: 1,2- 1,3-, and 1,4-. All are colorless liquids, immiscible in water, with similar boiling points. They are classified as aromatic hydrocarbons. They bear two substituents: an isopropyl (CH(CH₃)₂) group and a methyl group.

Dimethylglycine (DMG) is a derivative of the amino acid glycine with the structural formula (CH₃)₂NCH₂COOH. It can be found in beans and liver, and has a sweet taste. It can be formed from trimethylglycine upon the loss of one of its methyl groups. It is also a byproduct of the metabolism of choline.

When DMG was first discovered, it was referred to as Vitamin B₁₆, but, unlike true B vitamins, deficiency of DMG in the diet does not lead to any ill-effects and it is synthesized by the human body in the citric acid cycle meaning it does not meet the definition of a vitamin.

Dimethylformamide, DMF is an organic compound with the chemical formula HCON(CH₃)₂. Its structure is HC(=O)−N(−CH₃)₂. Commonly abbreviated as DMF (although this initialism is sometimes used for dimethylfuran, or dimethyl fumarate), this colourless liquid is miscible with water and the majority of organic liquids. DMF is a common solvent for chemical reactions. Dimethylformamide is odorless, but technical-grade or degraded samples often have a fishy smell due to impurity of dimethylamine. Dimethylamine degradation impurities can be removed by sparging samples with an inert gas such as argon or by sonicating the samples under reduced pressure. As its name indicates, it is structurally related to formamide, having two methyl groups in the place of the two hydrogens. DMF is a polar (hydrophilic) aprotic solvent with a high boiling point. It facilitates reactions that follow polar mechanisms, such as S_N2 reactions.

Menadione is a natural organic compound with the formula C₆H₄(CO)₂C₂H(CH₃). It is an analog of 1,4-naphthoquinone with a methyl group in the 2-position. It is sometimes called vitamin K₃. Use is allowed as a nutritional supplement in animal feed because of its vitamin K activity.

Methylation, in the chemical sciences, is the addition of a methyl group on a substrate, or the substitution of an atom (or group) by a methyl group. Methylation is a form of alkylation, with a methyl group replacing a hydrogen atom. These terms are commonly used in chemistry, biochemistry, soil science, and biology.

In biological systems, methylation is catalyzed by enzymes; such methylation can be involved in modification of heavy metals, regulation of gene expression, regulation of protein function, and RNA processing. In vitro methylation of tissue samples is also a way to reduce some histological staining artifacts. The reverse of methylation is demethylation.