Pyrimidine

Pyrimidines are six-membered aromatic heterocyclic compounds containing two meta-nitrogen atoms and have a special ultraviolet spectrum due to the presence of conjugated double bonds in the pyrimidine. Pyrimidine is a colorless crystal, melting point 22 ° C, soluble in water, its basicity is weaker than pyridine, and electrophilic substitution reaction is also more difficult than pyridine. However, nucleophilic substitutions are more likely to occur, and pyrimidine derivatives are widely found in nature. For example, vitamin B1, uracil, cytosine, and thymine all contain a pyrimidine structure. Nucleic acids contain several important pyrimidine derivatives that are important bases in nucleic acids. It mainly contains cytosine and thymine in DNA, and mainly contains cytosine and uracil in RNA, and also contains a small number of pyrimidine-modified bases in some nucleic acids, for example, one of the chemical constituents of pyrimidine base nucleotides. It consists of carbon, nitrogen, hydrogen, oxygen and other elements. Pyrimidine bases include uracil, cytosine, and thymine, in which uracil and cytosine form bases in ribonucleic acid molecules, and thymine and cytosine form bases in deoxyribonucleic acid molecules. The pyrimidine base has a strong absorption effect on ultraviolet light having a wavelength of 250 to 280 nm. The raw materials for the synthesis are derived from carbamyl phosphate and aspartic acid, and the pyrimidine base can also be metabolized by metabolism into carbon dioxide, beta alanine and beta ammonia isobutyric acid. Some patients may cause pyrimidine-alkaline metabolism due to congenital factors or taking certain drugs, causing orotic aciduria.