Dihydrouracil

Chemical structure of Dihydrouracil

Dihydrouracil is a chemical compound that belongs to the class of pyrimidine derivatives. It is a reduced form of uracil, which is one of the four nucleobases found in RNA. Dihydrouracil is formed through the reduction of uracil by the enzyme dihydropyrimidine dehydrogenase (DPD). This enzyme plays a crucial role in the metabolism of pyrimidine nucleotides.

Structure and Properties

Dihydrouracil has a molecular formula of C4H6N2O2 and a molecular weight of 114.10 g/mol. It is a white crystalline solid that is soluble in water. The compound exists in two tautomeric forms, keto and enol, with the keto form being the more stable one.

Biological Significance

Dihydrouracil is an important intermediate in the metabolism of uracil and other pyrimidine nucleotides. It is produced as a byproduct during the degradation of thymine and uracil in the body. Dihydrouracil is further metabolized to β-alanine by the enzyme dihydropyrimidinase. β-alanine is then used in the synthesis of pantothenic acid, a component of coenzyme A.

Clinical Significance

Dihydrouracil has gained attention in the field of pharmacology due to its association with the efficacy and toxicity of certain drugs. The enzyme DPD, responsible for the conversion of uracil to dihydrouracil, is involved in the metabolism of several chemotherapeutic agents, such as 5-fluorouracil (5-FU). Variations in the DPD enzyme activity can affect the response to these drugs, leading to differences in drug efficacy and toxicity among individuals.

See Also

• Uracil
• Pyrimidine
• Dihydropyrimidine dehydrogenase
• 5-fluorouracil