On December 24, 2015, Lenz, Stefan A. P.; Kellie, Jennifer L.; Wetmore, Stacey D. published an article.COA of Formula: C6H5N3O The title of the article was Glycosidic Bond Cleavage in DNA Nucleosides: Effect of Nucleobase Damage and Activation on the Mechanism and Barrier. And the article contained the following:
Although DNA damage can have a variety of deleterious effects on cells (e.g., senescence, death, and rapid growth), the base excision repair (BER) pathway combats the effects by removing several types of damaged DNA. Since the first BER step involves cleavage of the bond between the damaged nucleobase and the DNA sugar-phosphate backbone, we have used d. functional theory to compare the intrinsic stability of the glycosidic bond in a number of common DNA oxidation, deamination, and alkylation products to the corresponding natural nucleosides. Our calculations predict that the dissociative (SN1) and associative (SN2) pathways are nearly isoenergetic, with the dissociative pathway only slightly favored on the Gibbs reaction surface for all canonical and damaged nucleosides, which suggests that DNA damage does not affect the inherently most favorable deglycosylation pathway. More importantly, with the exception of thymine glycol, all DNA lesions exhibit reduced glycosidic bond stability relative to the undamaged nucleosides. Furthermore, the trend in the magnitude of the deglycosylation barrier reduction directly correlates with the relative nucleobase acidity (at N9 for purines or N1 for pyrimidines), which thereby provides a computationally efficient, qual. measure of the glycosidic bond stability in DNA damage. The effect of nucleobase activation (protonation) at different sites predicts that the positions leading to the largest reductions in the deglycosylation barrier are typically used by DNA glycosylases to facilitate base excision. Finally, deaza purine derivatives are found to have greater glycosidic bond stability than the canonical counterparts, which suggests that alterations to excision rates measured using these derivatives to probe DNA glycosylase function must be interpreted in reference to the inherent differences in the nucleoside reactivity. Combined with previous studies of the deglycosylation of DNA nucleosides, the current study provides a greater fundamental understanding about the reactivity of the glycosidic bond in damaged DNA, which has direct implications to the function of critical DNA repair enzymes. The experimental process involved the reaction of Imidazo[1,2-c]pyrimidin-5(6H)-one(cas: 55662-66-3).COA of Formula: C6H5N3O
The Article related to glycosidic bond cleavage dna damage nucleoside nucleobase deglycosylation, General Biochemistry: Nucleic Acids and Their Constituents and other aspects.COA of Formula: C6H5N3O
Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem