プリン 化学特性,用途語,生産方法
解説
プリン．プリンそのものは天然に存在しないが，各種の誘導体が天然に存在している．植物においては，カフェイン(茶，コーヒー)，テオブロミン(カカオ)，テオフィリン(茶)，キサンチン(種子，葉，果実)など．動物においては，キサンチン(尿，血液，肝臓)，アデニン，グアニン(核酸)，尿酸(尿)などがある．4,5-ジアミノピリミジンを二酸化炭素の存在下でギ酸とともに加熱するか，尿酸を三塩化リンで処理し，トリクロロ誘導体にして，ヨウ化水素で還元すると得られる．無色の針状晶．融点216～217 ℃．水，熱エタノールに易溶，熱酢酸エチル，アセトンに微溶，エーテル，クロロホルムに不溶．アデニン，グアニンは核酸中の塩基として重要であり，尿酸，キサンチンは生体のプリン代謝に関係が深い．プリン誘導体はこのように生化学上重要なものが多い．
化学的特性
very slightly yellow to cream crystalline powder
使用
Organic synthesis, metabolism, and biochemi-
cal research.
(2) One of a number of basic compounds found in
living matter and having a purine-type molecular
structure.
定義
ChEBI: The 9H-tautomer of purine.
生合成
Basically, the same pathway is found in all organisms capable of purine biosynthesis de novo. The initial substrate is the highly phosphorylated sugar 5-phosphoribosyl-α-1-pyrophosphate (PRPP). An amino group is transferred from glutamine to PRPP catalyzed by the enzyme glutamine PRPP amidotransferase. After that, it takes four reactions to complete the imidazole ring and an additional five reactions to synthesize the pyrimidine moiety and thereby to complete the purine molecule. In some bacteria (e.g., B. subtilis and Escherichia coli), the third step is also catalyzed by a second enzyme (purT) that uses formate instead of a tetrahydrofolic acid derivative as formyl donor. The sixth step has been found to be a two-step reaction, which in some organisms is catalyzed by a single enzyme. The end product of the de novo purine biosynthetic pathway is IMP. After the formation of IMP, purine synthesis splits into two separate pathways leading to the synthesis of AMP and GMP. The control point for feedback inhibition by purine nucleotides and activation by PRPP is on the activity of the first enzyme of the pathway glutamine PRPP amidotransferase. The branching from IMP is regulated by ATP and GTP to ensure a proper balance between ATP and GTP.
一般的な説明
Purine is a heterocyclic organic compound constituting a pyrimidine ring fused to an imidazole ring.
純化方法
It crystallises from toluene or EtOH, and sublimes at 100-150o/0.1mm or 160o/10-4mm. The picrate has m 207-209o after crystallisation from 20volumes of H2O. [Beilstein 26 H 354, 26 III/IV 1736.]
プリン 上流と下流の製品情報
原材料
準備製品