Quantum‐chemical examination of interaction of cytostatic‐fluorouracil with deoxyribonucleic acids

This is the authors' abstract. We don't add key points for this paper.

Within the framework of semiempirical method of quantum chemical PM3, the possibility of formation of paired stack structures under interaction of fluorouracil with pyrimidine and purine nitrogenous bases of nucleotides has been examined. Possible mechanism of transformation of 2‐deoxyuridine‐5‐monophosphate into metabolite‐5‐fluorin‐2‐deoxyuridine‐5‐monophosphate has been given. The calculations that were made allow to suppose that biotransformation of 5‐FU in 5‐fluorin‐2‐deoxyuridine‐5‐monophosphate, most likely, is carried out not in free nucleotides, but in the structure of DNA in two nucleotide triplets UUC and UGU, including the case when directly two nucleotides of deoxyuridine monophosphate, are transformed into 5‐fluorin‐2‐deoxyuridine‐5‐monophosphate. Cytostatic ability of 5‐FU is increased by its capacity to be selectively embedded into nucleotide triplets creating new chemical compounds that violate matrix RNA formation and accordingly violate protein synthesis.