3-Hydroxybutyrate
3-Hydroxybutyrate is a hydroxy fatty acid anion and ketone body synthesized in the liver from acetyl-Coenzyme A (acetyl-CoA) by the enzyme 3-hydroxybutyrate dehydrogenase. 3-hydroxybutyrate can be used as an energy source when glucose levels drop. Elevated urine and serum levels of 3-hydroxybutyrate are seen in ketosis and ketoacidosis.