3-oxauracil (OU)

3-oxauracil (2H-1,3-oxazine-2,6(3H)-dione) is a pyrimidine analogue and antimetabolite that has been investigated for its potential as an anticancer and antiviral agent (Invest New Drugs 1997, 15(4):289-293; Cancer Treat Rep 1978, 62(12):2121-3). It is characterized by the substitution of the nitrogen atom at the 3-position of the uracil ring with an oxygen atom, forming an oxazine core (CAS Common Chemistry). Biologically, 3-oxauracil functions as an inhibitor of the de novo pyrimidine biosynthetic pathway, specifically targeting the enzymes orotate phosphoribosyltransferase (OPRT) and orotidine-5'-phosphate decarboxylase (ODC) (Biochem Pharmacol 1979). By inhibiting these enzymes, it depletes the cellular pool of pyrimidine nucleotides, which are essential for the synthesis of DNA, RNA, and proteins. This leads to the suppression of cell proliferation and the induction of apoptosis, particularly in rapidly dividing cancer cells such as those found in leukemia, pancreatic, and colon cancers (Invest New Drugs 1997). Furthermore, 3-oxauracil is recognized as a substrate for bacterial cytosine deaminase, which can hydrolyze it into malonate semialdehyde (J Biol Chem 2011, 286(24):21545-55). Although referred to as a target in some contexts, 3-oxauracil is a small molecule drug candidate rather than a therapeutic target protein like a receptor or enzyme.

Other names

2H-1,3-oxazine-2,6(3H)-dione1,3-oxazine-2,6-dioneNSC 1630382,3-dihydro-6H-1,3-oxazine-2,6-dione

Inhibition of orotate phosphoribosyltransferase (OPRT) and orotidine-5'-phosphate decarboxylase (ODC), leading to depletion of pyrimidine nucleotides and inhibition of DNA/RNA synthesis.