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|Section2= |Section3= |Section4= }} ''beta''-Hydroxybutyric acid (also known as ''beta''-hydroxybutyrate, 3-hydroxybutyric acid or 3-hydroxybutyrate) is an organic compound with the formula CH3CH(OH)CH2CO2H. It is a beta hydroxy acid. It is a chiral compound having two enantiomers, D-3-hydroxybutyric acid and L-3-hydroxybutyric acid. Its oxidized and polymeric derivatives occur widely in nature. ==Biosynthesis== In humans, ''beta''-hydroxybutyrate is synthesized in the liver from acetoacetate, the first ketone produced in the fasting state. The biosynthesis is catalyzed by the enzyme beta-hydroxybutyrate dehydrogenase. Although not a ketone itself, the concentration of ''beta''-hydroxybutyrate, like that of other ketone bodies, is raised in ketosis. This elevated beta-hydroxybutyrate level seen in ketosis is naturally expected due to the fact that, as mentioned above, it is formed from acetoacetate. The compound can be used as an energy source by the brain when blood glucose is low. Diabetic patients can have their ketone levels tested via urine or blood to indicate diabetic ketoacidosis. In alcoholic ketoacidosis, this ketone body is produced in greatest concentration. Both types of ketoacidosis result in an increase ''beta''-hydroxybutyrate to oxaloacetate ratio, resulting in TCA cycle stalling and shifting of glucose towards ketone body production. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Beta-Hydroxybutyric acid」の詳細全文を読む スポンサード リンク
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