methyl group

The electrophilic reaction of methyl pyropheophorbide-a ( MPP-a) demonstrates that the electrophilic addition reaction and the electrophilic substitution reaction occur on the vinyl group at 3-position and 20-meso-position, respectively.

焦脱镁叶绿酸a甲酯与溴素的亲电反应表明：在3位乙烯基上发生亲电加成反应，而与20位的meso氢则发生亲电取代反应。

DNA methylation is the only known covalent modification of DNA molecule. It is accomplished by transfer of the methyl group from S-adenosyl methionine to 5 position of the purine ring of cytosine.

DNA甲基化（DNA Methylation）是目前已知的唯一天然的DNA共价修饰方式，由DNA转移酶催化，将S-腺苷甲硫氨酸上的甲基转移到胞嘧啶嘌呤环的第五位碳原子上。

The methyl group ( CH3) attached to the methionine sulfur atom in SAM is chemically reactive.

甲基基团（CH3）附着在SAM中蛋氨酸硫原子具有化学反应性。

The simulation results suggested that the EVAP showed significant effects on the nucleation and growth of the paraffin crystal when the acetate concentration was around 30% and there existed one branched methyl group near the acetate group in each block.

在各种乙烯醋酸乙烯丙烯（EVAP）降凝剂中，当EVAP酯含量在30%左右，且在每个链段含有一个靠近酯基的甲基支链时容易在蜡晶的成核和生长过程中发挥作用。

As an electrophilic agent, the methyl group of methoxy species can directly attack benzene ring to produce toluene via electrophilic substitution reaction.

甲氧基物种的甲基作为一种亲电试剂，可以直接进攻苯环发生亲电取代烷基化反应生成甲苯。

Grignard reaction of methyl pyropheophorbide substituted at 3-position by acyl group and synthesis of chlorophyll derivatives

3-酰基焦脱镁叶绿酸甲酯的格氏反应及其叶绿素衍生物的合成

The relative removal rate of methyl and methylene group showed the shape of M with the increase of temperature.

甲基与亚甲基的相对脱除速率随温度呈现M型关系。

Yin-tonic Effects of Timosaponin Aglycone with Stereoisomeric Change of C-25 methyl group on Hyperthyroid mice

知母甾体皂甙元C-25甲基立体异构对滋阴作用的影响

Codeine has the same structure as morphine, but the phenol group masked as a methyl ether.

可待因也有和吗啡相同的结构, 但是酚基被甲基醚屏蔽了,结果.

Cyclic amide ( incl. cyclic carbamates) and their derivatives ( excl. ureines and their derivatives), and salts thereof Grignard reaction of methyl pyropheophorbide substituted at 3-position by acyl group and synthesis of chlorophyll derivatives

环酰（包括环氨基甲酸酯）及其衍生物（不包括烷基脲及基衍生物）和它们的盐类3-酰基焦脱镁叶绿酸甲酯的格氏反应及其叶绿素衍生物的合成

Genes get switched off when a chemical mark, a methyl group, is added to the DNA.

DNA的甲基化会使基因表达关闭.