一二三四区视频,亚洲少妇熟女色,日本久热无码视频网,欧美国产日韩大尺度,亚洲a视频,久久少妇一区二区,日韩999无码视频,刺激久久久久久久,啊啊啊啊不要啊在线

Pyrimidine

Pyrimidine is a six-membered aromatic heterocyclic compound containing two nitrogen atoms on meta-position. Due to the conjugated double bonds pyrimidine has a special UV spectrum. Pyrimidine is a colorless crystal, the melting point of which is 22 ℃. It’s soluble in water. It’s a weaker alkaline than pyridine so that it’s less prone to electrophilic substitution reactions than pyridine, but more prone to nucleophilic substitution. Pyrimidine derivatives are widely distributed in nature, e.g. vitamin B1, uracil, thymine, and cytosine contain the pyrimidine structure.

Nucleic acid contains several important pyrimidine derivatives as important bases.

DNA mainly contains cytosine and thymine and RNA mainly contains cytosine and uracil. Some nucleic acids also contain a small amount of pyrimidine modified bases, for example:

Pyrimidine base is one of the chemical compositions of nucleotides, consisting of carbon, nitrogen, hydrogen, oxygen and other elements. Pyrimidine bases include uracil, cytosine and thymine, wherein cytosine and uracil constitute the bases in ribonucleic acid molecule, thymine and cytosine bases constituting the DNA molecule. Pyrimidine base has a strong absorption of ultraviolet light of 250 ~ 280nm. The synthesis raw materials originate from carbamoyl phosphate and aspartic acid. Pyrimidine base can be metabolized into carbon dioxide, β-alanine and βammonia isobutyrate and other substances. Due to congenital factors or taking certain medications, some patients suffer from metabolic disorder of pyrimidine bases, which causes orotic aciduria.

  • 1
HomePage | Member Companies | Advertising | Contact us | Previous WebSite | MSDS | CAS Index | CAS DataBase
Copyright © 2016 ChemicalBook All rights reserved.
迭部县| 海晏县| 内乡县| 玉田县| 福安市| 当雄县| 涞水县| 鄂州市| 中宁县| 玉林市| 合川市| 德江县| 龙南县| 贡觉县| 章丘市| 天台县| 三都| 顺义区| 航空| 象州县| 余姚市| 蒲城县| 武冈市| 彰化市| 兴宁市| 海盐县| 台中市| 崇左市| 银川市| 蓬莱市| 宁晋县| 兰溪市| 株洲市| 辽中县| 孟州市| 乐东| 营口市| 平顶山市| 砀山县| 湖南省| 荔浦县|