Uridine monophosphate

Uridine monophosphate, also known as 5′-uridylic acid, is a nucleotide that is used as a monomer in RNA. It is an ester of phosphoric acid with the nucleoside uridine. UMP consists of the phosphate group, the pentose sugar ribose, and the nucleobase uracil; hence, it is a ribonucleotide monophosphate. As a substituent or radical its name takes the form of the prefix uridylyl-. The deoxy form is abbreviated dUMP. Covalent attachment of UMP is called uridylylation.

Biosynthesis

Uridine monophosphate is formed from orotidine 5′-monophosphate in a decarboxylation reaction catalyzed by the enzyme orotidylate decarboxylase. Uncatalyzed, the decarboxylation reaction is extremely slow. Adequately catalyzed, the reaction takes place once per second, an increase of 10¹⁷-fold.
In humans, the orotidylate decarboxylase function is carried out by the protein UMP synthase. Defective UMP synthase can result in orotic aciduria, a metabolic disorder.

In a study, gerbils fed a combination of uridine monophosphate, choline, and docosahexaenoic acid were found to have significantly improved performance in running mazes over those not fed the supplements, implying an increase in cognitive function.

In brain research studies, uridine monophosphate is used as a convenient delivery compound for uridine. Uridine is the active component of this compound. Uridine is present in many foods, mainly in the form of RNA. Non-phosphorylated uridine is not bioavailable beyond first-pass metabolism, as it is almost entirely catabolised in the liver and gastrointestinal tract.