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定義
本品は、核酸誘導体のナトリウム塩であり、次の化学式で表される。
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性質
フラビンアデニンジヌクレオチドは，橙黄色の結晶様粉末．黄緑色の蛍光を出す．λmax 370，450 nm，還元型は450 nm の吸収を示さない．水に易溶，アルコール類に微溶．生体内では，アミノ酸，カルボン酸，還元NAD，チオール基などの酸化反応の補酵素として作用する．
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解説
C27H33N9O15P2(785.56)．FADと略し，還元型をFADH2と記す．体内の酸化還元酵素の補酵素として機能する物質．ビタミンB2から作られる．フラビン酵素の補欠分子族の一つ．フラビンモノヌクレオチド(FMN)とアデニル酸(AMP)との結合物で，イソアロキサジン環が酸化型および還元型をとることによって，生体の酸化還元系で水素伝達の作用をする重要な物質である．酵母，ウマの心筋，腎臓，肝臓などから抽出精製することができる．このような非対称ピロリン酸エステルの合成は困難であったが，リン酸アミデート法により，FMNとAMPから合成されるようになった．
フラビンアデニンジヌクレオチドは，とくに重要な作用としては，生体の酸化的リン酸化に関与していることである．すなわち，ミトコンドリアにおける電子伝達系の中枢的位置に二つのフラビン酵素があり，この活性によってATPの生成が左右される．森北出版「化学辞典（第2版）
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効能
ビタミンB2補充薬
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説明
Flavin adenine dinucleotide (FAD) is a cofactor for cytochrome-b5 reductase, the enzyme that maintains hemoglobin in its functional reduced state, and for glutathione reductase. This enzyme also protects erythrocytes from oxidative damage. FAD is a redox cofactor of several essential reactions in metabolism. This cofactor exists in two redox states, with FAD and FADH2 being the oxidized and reduced forms, respectively. FAD is formed of a riboflavin moiety (vitamin B2) coupled to a phosphate group of an ADP molecule. The reaction starts with the conversion of riboflavin into flavin mononucleotide catalyzed by riboflavin kinase. Flavin mononucleotide is subsequently transformed into FAD by adding an AMP moiety from ATP catalyzed by FAD-synthase. Therefore, FAD availability is tightly dependent on vitamin B2 and energy metabolism[1].
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化学的特性
solid
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使用
Labelled Flavine Adenine
xidase. Riboflavin kinase tumor necrosis factor receptor 1 NADPH oxidase
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定義
An adenine
nucleotide containing two phosphate groups esterified to the sugar moiety at the 5′-position.
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純化方法
Small quantities of FAD are purified by paper chromatography using tert-butyl alcohol/water, cutting out the main spot and eluting with water. Larger amounts can be precipitated from water as the uranyl complex by adding a slight excess of uranyl acetate to a solution at pH 6.0, dropwise and with gentle stirring. The solution is set aside overnight in the cold, and the precipitate is centrifuged off, washed with small portions of cold EtOH, then with cold peroxide-free diethyl ether. It is dried in the dark under vacuum over P2O5 at 50-60o. The uranyl complex is suspended in water, and, after adding sufficient 0.01M NaOH to adjust the pH to 7, the precipitate of uranyl hydroxide is removed by centrifugation [Huennekens & Felton Methods Enzymol 3 954 1957]. It can also be crystallised from water. It should be kept in the dark. More recently it was purified by elution from a DEAE-cellulose (Whatman DE 23) column with 0.1M phosphate buffer pH 7, and the purity was checked by TLC. [Holt & Cotton, J Am Chem Soc 109 1841 1987, Beilstein 26 III/IV 3632.]
