Methylation


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methylation

[‚meth·ə′lā·shən]
(organic chemistry)
A chemical process for introducing a methyl group (CH3‒) into an organic compound.

Methylation

 

the replacement of a hydrogen, metal, or halogen atom by a methyl group,—CHs; it is effected by the action of various methylating agents—for example, methyl iodide, CH3I; dimethyl sulfate, (CH3O)2SO2; methylsulfuric acid, CH3OSO3H; methyl esters of organic sulfo acids; methanol, CHjOH; and dimethyl ether, (CH3)2O. Methylation is widely used in organic synthesis in industry. For example, methylation with dimethyl sulfate is used in the synthesis of pharmaceuticals (for example, metapyrin); amidopyrine is prepared by methylation with formaldehyde and a reducing agent, usually formic acid.

Aromatic hydrocarbons are readily methylated by the action of methyl chloride or dimethyl ether in the presence of AlCl3. Methylaniline and dimethylaniline are prepared industrially by methylation of aniline with methanol over A12O3 at high temperatures:

Methylation with diazomethane is widely used to produce methyl esters of carboxylic acids under laboratory conditions, according to the formula

R—COOH + CH2N2→RCOOCH3 + N2

B. L. DIATKIN

References in periodicals archive ?
DNA methylation is an essential component of epigenetics and plays a critical role in many biological events.
DNA methylation in eukaryotes is a significant crucial epigenetic modification and is the most well-studied phenomenon at present (Gavery and Roberts, 2010).
The goal of this paper is to develop, using the Illumina[R]450K methylation platform, a biomarker in newborns of sustained smoking by the mother during pregnancy that can be easily applied to other newborn studies with either Illumina[R]450K or Illumina[R] Infinium[R] MethylationEPIC BeadChip (Illumina[R]EPIC) methylation data.
They added that this study is the largest one examining the effects of smoking on DNA methylation.
During development, the determination of mesenchymal cells to either a myogenic, adipogenic, osteogenic or chrondrogenic lineage is in part due to stable modifications made to the methylation pattern of DNA that prevents the transcription of genes from other lineages (Barr, 2010).
An increase in methylation typically corresponds to a decrease in the expression of a gene, so it affects how much a particular gene is functioning.
Higher amounts of DNA methylation (hypermethylation), like that found by the researchers in some tumor DNA, decrease a gene's activity.
DNA methylation is a physical modification to the genetic material (DNA) of a cell, which can alter the behavior of that cell.
At 9 and 12 mo, the femoral feed artery was isolated after euthanasia under anesthesia for reactivity studies [15] and for DNA extraction and methylation quantification.
HPV-ASSOCIATED OPSCC DISPLAYS DISTINCT DNA METHYLATION PROFILES
The aim of this study was to identify DNA methylation pattern of estrogen receptor alpha (ERa) gene promoter region and to evaluate its association with milk production performance of Xinong Saanen dairy goats.