Drugs for insomnia involve mainly benzodiazepine drugs, non-benzodiazepine drugs (such as pyrimidine pyrazole, pyrrole ring ketones, GABA receptor agonists and reuptake inhibitors) and other sleep-promoting agent (including antidepressant drugs, cytokines, melatonin and hormonelike drugs), etc. The development of new sedative-hypnotics provides a new choice for the treatment of insomnia.
治疗失眠的药物主要有苯二氮类药物和非苯二氮类药物（如吡唑嘧啶类、吡咯环酮类、GABA受体激动药及其再摄取抑制药等）以及其他有助于睡眠的药物（包括抗抑郁药物、细胞因子、褪黑素及激素类药物）等；新型催眠药物的研制为失眠的治疗提供了新的选择。
Pyrimidine: Any of a class of heterocyclic compounds with a ring structure of four carbon and two nitrogen atoms.
嘧啶：具有环状结构(由4个碳原子和2个氮原子组成)的一类杂环化合物。
Pyrimidine: Any of a class of heterocyclic compound s with a ring structure of four carbon and two nitrogen atoms.
嘧啶：具有环状结构(由4个碳原子和2个氮原子组成)的一类杂环化合物。
Many of the aza quinazolines have showed potent activity, such as pyrido[2, 3-d]pyrimidine, pyrido [3, 2-d]pyrimidine, pyrido[4, 3-d]pyrimidine, pyrido[3, 4-d]pyrimidine, and pyrimido [5, 4-d]pyrimidine. Moreover, the compounds that the benzene in quinazoline ring was substituted by five-member rings, such as pyrrolo[2, 3-d]pyrimidine, pyrazolo[3, 4-d]pyrimidine, can also inhibit the EGFR and show bright prospects.
然而喹唑啉环并非EGFR抑制剂所必须的，在随后的研究中，人们发现许多氮杂喹唑啉类也有很好的活性，如吡啶并[2，3-d]嘧啶类、吡啶并[3，2-d]嘧啶类、吡啶并[4，3-d]嘧啶类、吡啶并[3，4-d]嘧啶类、嘧啶并[5，4-d]嘧啶类，也就是在喹唑啉环的5，6，7，8-位都可以氮杂，且都有活性。
Ten benzoylthiourea s containing substituted pyrimidine ring were synthesized, among them seven are new compounds.
合成了10种含不同取代嘧啶环的苯甲酰硫脲类化合物，其中7个为未见文献报道的新化合物。
In the mammal, DNA methylation only occurs on cytosine residues found within cytosine and guanine dinucleotide and involves methylation in the fifth carbon of DNA pyrimidine ring, resulting in the formation of 5-methylcytosine.
表遗传学是指不发生DNA序列改变的、可遗传的基因表达改变，包括两个方面的重要内容：DNA甲基化；组蛋白修饰(甲基化、乙酰化、磷酸化、泛素化和糖基化)。
The results show that the herbicidal activity decreases as the hydrogen atoms of the alkoxy group at 4 position of the pyrimidine ring are substituted by alkyl, alkoxy groups or fluorine atoms.
结果表明，嘧啶环上烷氧基中的氢原子被烷基、烷氧基及氟原子等基团取代后，磺酰脲分子的除草活性降低。
Cytosine organic compound of the pyrimidine family, often called a base, consisting of a single ring, containing both nitrogen and carbon atoms, and an amino group.
胞嘧啶：嘧啶族的有机化合物。常被称为基，包含一个单环，内有氮原子和碳原子，还有氨群。
Methylation of cytosine in the5 position of the pyrimidine ring is a major modification of the DNA in most organisms.
嘧啶环5位的胞嘧啶甲基化是大部分生物体中一个主要的DNA甲基化修饰。
According to the bioisosterism principles, six compounds containing substituted pyrimidine ring were designed and synthesized. Among them five are new compounds.
根据生物电子等排原理，设计合成了6种含取代嘧啶环的目标化合物，其中5种为新化合物。
The influence of substituted groups on the chemical shift of protons of pyrimidine ring was discussed. And the assignment of the peaks in IR and 1H NMR spectra was made.
并对所合成的化合物的结构进行了表征，讨论了取代基对嘧啶环质子化学位移的影响，确定了红外光谱以及~1HNMR谱中各峰的归属。
Bis-Crown ether containing pyrimidine ring & ⅱ. sodium, potassium and caesium ion selective PVC membrane electrodes based on Bis-Crown ethers as carrier
含嘧啶环的双冠醚&Ⅲ.用双冠醚作载体的PVC膜离子选择性电极性质的研究
Some of these compounds showed good fungicidal activity after introduction of dimethylamino into the 2-position of pyrimidine ring.
在嘧啶环的2位上导入二甲氨基时表现出杀菌活性，但在嘧啶环的5位上有甲基取代基时，杀菌活性下降。
To substitute the ring A of the aurones with pyrimidine, a series of aza aurones were synthesized.
以嘧啶环替换噢中的A环，合成了一系列氮杂噢类化合物。
Meantime, lots of new compounds containing pyrimidine-cycle own potential bioactivity. The relation between their chemical structure and biological activity is depended on affect of substituents in different position of pyrimidin ring.
含有嘧啶环的新研制的众多化合物也具有生物活性，其化学结构与生物活性之间的关系，主要体现在嘧啶环不同位置的取代基所产生的影响。