Uracil

Uracil is a wheat germ.^[2] Uracil is a planar, unsaturated compound that has the ability to absorb light^[3]

Properties

Found in phosphate attaches to uridine, uridine 5'-monophosphate is produced.^[3]

Uracil, U, undergoes amide-imidic acid tautomeric shifts because of its resonance structures resulting from the N and O substitutents. Also because any nuclear instability the molecule may have from the lack of formal pH=7. The lactam structure is the most common form of uracil.

Uracil also recycles itself to form nucleotides by undergoing a series of phosphoribosyltransferase reactions.^[1] Degradation of uracil produces substrates, ammonia.^[1]

C₄H₄N₂O₂ → H₃NCH₂CH₂COO^- + NH₄ + CO₂

Oxidative degradation of uracil produces urea and maleic acid in the presence of oxygen and Fe²⁺.

Uracil is a pK_a of less than or equal to 12. The basic pK_a = -3.4, while the acidic pK_a = 9.38_{9. In the gas phase, uracil has 4 sites that are more acidic than water.^[6]}

Synthesis

There are many laboratory syntheses of uracil available. The first reaction is the simplest of the syntheses, by adding water to maleic acid with urea in fuming sulfuric acid^[2] as seen below also. Uracil can also be synthesized by a double decomposition of thiouracil in aqueous chloroacetic acid.^[2]

C₄H₅N₃O + H₂O → C₄H₄N₂O₂ + NH₃

C₄H₄O₄ + CH₄N₂O → C₄H₄N₂O₂ + 2 H₂O + CO

Photodehydrogenation of 5,6-diuracil, which is synthesized by beta-urea, produces uracil.^[7]

Reactions

Uracil readily undergoes regular reactions including halogens because of the presence of more than one strongly electron donating group.^[2]

Uracil readily undergoes addition to phosphates to partake in synthesis and further reactions in the body. Uracil becomes Uridine-monophosphate (UMP), uridine-diphosphate (UDP), uridine-triphosphate (UTP), and uracil-diphosphate glucose (UDP-glucose). Each one of these molecules in synthesized in the body and has specific functions.

When uracil reactes with anhydrous hydrazine a first order kinetic reaction occurs and the ring of uracil opens up.^[8] If the pH of the reaction increases to >10.5 the uracil anion forms making the reaction go much slower, the same slowing of the reaction occurs if the pH decreases because of the protonation of the hydrazine.^[8] The reactivity of uracil is unchanged even if the temperature changes.^[8]

Uses

Uracil can be used for antimetabolite) used to masquerade as uracil during the nucleic acid replication process.^[1] The drug molecule also fools the enzymes that help in this process to incorporate this compound in the replication and not uracil, this causes the biological polymer (cancer) not to continue synthesizing.^[1]

Uracil's use in the body is to help carry out the synthesis of many enzymes necessary for cell function through bonding with riboses and phosphates.^[1] Uracil serves as aldehydes.^[9]

It can also increase the risk for cancer in cases where the body is extremely deficient in folate.^[10] The deficiency in folate leads to increased ratio of deoxyuracilmonophosphates (dUMP)/deoxythyminemonophosphates (dTMP) and uracil misincorporation into DNA and eventually low production of DNA.^[10]

Uracil can be used to determine sunflower crops, vineyards, berry plantations, and orchards.^[12]

References

1. ^ ^{a b c d e f g} Garrett, Reginald H.; Grisham, Charles M. Principals of Biochemistry with a Human Focus. United States: Brooks/Cole Thomson Learning, 1997.
2. ^ ^{a b c d e f} Brown, D.J. Heterocyclic Compounds: Thy Pyrimidines. Vol 52. New York: Interscience, 1994.
3. ^ ^{a b} Horton, Robert H.; et al.Principles of Biochemistry. 3rd ed. Upper Saddle River, NJ: Prentice Hall, 2002.
4. ^ ^{a b} www.madsci.org
5. ^ Zorbach, W.W. Synthetic Procedures in Nucleic Acid Chemistry: Physical and Physicochemical Aids in Determination of Structure. Vol 2. New York: Wiley-Interscience, 1973.
6. ^ Lee, J.K.; Kurinovich, Ma. J Am Soc Mass Spectrom.13(8), 2005, 985-95.
7. ^ Chittenden, G.J.F.; Schwartz, Alan W. Nature.263,(5575), 350-1.
8. ^ ^{a b c} Kochetkov, N.K. and Budovskii, E.I. Organic Chemistry of Nucleic Acids Part B. New York: Plenum Press, 1972.
9. ^ ^{a b c} Brown, E.G. Ring Nitrogen and Key Biomolecules: The Biochemistry of N-Heterocycles. Boston: Lluwer Academic Publishers, 1998.
10. ^ ^{a b} Mashiyama, S.T; et al.'Anal Biochem. 330(1),2004, 58-69.
11. ^ Hildalgo, A; et al.'J Agric Food Chem.53(2),2005, 349-55.
12. ^ ^{a b} Pozharskii, A.F.; et al.Heterocycles in Life and Society: An Introduction to Heterocyclic Chemistry and Biochemistry and the Role of Heterocycles in Science, Technology, Medicine, and Agriculture. New York: John Wiley and Sons, 1997.