## 4 Discussion  
Throughout evolution, living organisms have developed protective mechanisms that eliminate unwanted R/NOS inside a cell [9]. Such mechanisms include enzymes such as superoxide dismutase (SOD), present either in prokaryotic or eukaryotic cells (its biosynthesis is controlled through the O\({}_{2}\)\({}^{\bullet-}\) level) [35], glutathione peroxidase catalysing the H\({}_{2}\)O\({}_{2}\) to H\({}_{2}\)O conversion [36], haem peroxidase [37], catalase [38], and many more. A different group of molecules involved in the removal of free radicals comprises so-called non-enzymatic antioxidants, which are small molecules that convert radicals into their inactive forms while becoming excited themselves (ascorbic acid, \(\alpha\)-tocopherol, glutathione, carotenoids, and flavonoids) [39]. These defence mechanisms against reactive oxygen and \begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline
**Molecule** & **VIP\({}^{\text{NE}}\)** & **VIP\({}^{\text{EQ}}\)** & **AIP** & **Molecule** & **VIP\({}^{\text{NE}}\)** & **VIP\({}^{\text{EQ}}\)** & **AIP** & **(_C10, C12, C13_)** & **HNE-dGua** \\ \hline
**dAdv** & 7.64 & 6.57 & 6.31 & **dGua** & 7.48 & 6.44 & 6.06 &
\begin{tabular}{c} Dias. \\ Form \\ \end{tabular} & VIP\({}^{\text{NE}}\) & VIP\({}^{\text{EQ}}\) & AIP \\ \hline \(\epsilon\)**-dAdo** & 7.23 & 6.34 & 6.12 & \({}^{\text{OXO}}\)**dG\({}^{\text{Anti}}\)** & 7.17 & 6.15 & 5.78 & \(RRR\) & 6.82 & 6.07 & 5.76 \\ \hline
**H-\(\epsilon\)-dAdo** & 7.07 & 6.25 & 6.00 & \({}^{\text{OXO}}\)**dG\({}^{\text{Syn}}\)** & 7.15 & 6.13 & 5.78 & \(RRS\) & 6.98 & 6.17 & 5.86 \\ \hline
**dCyt** & 7.93 & 6.85 & 6.52 & \(R\)**-OH-PdGua** & 6.99 & 6.13 & 5.84 & \(RSR\) & 6.90 & 6.12 & 5.82 \\ \hline \(\epsilon\)**-dCyt** & 7.35 & 6.40 & 6.11 & \(\mathbf{S}\)**-OH-PdGua** & 6.97 & 6.13 & 5.82 & \(RSS\) & 6.92 & 6.15 & 5.82 \\ \hline
**H-\(\epsilon\)-dCyt** & 7.14 & 6.28 & 5.98 & **M1-dGua** & 7.34 & 6.49 & 6.22 & \(SRR\) & 6.80 & 6.07 & 5.72 \\ \hline
**H-\(\epsilon\)-dGua** & 6.78 & 5.96 & 5.80 & \(\mathbf{N1}\)**-\(\epsilon\)-dGua** & 6.93 & 6.07 & 5.88 & \(SRS\) & 7.00 & 6.21 & 5.91 \\ \hline  & & & & & \(\mathbf{N2}\)**-\(\epsilon\)-dGua** & 9.66 & 8.75 & 6.18 & \(SRR\) & 6.92 & 6.16 & 5.91 \\ \hline  & & & & & & & & \(SSS\) & 6.99 & 6.19 & 5.87 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: The electronic properties, in [eV], of 2\({}^{\prime}\)-deoxynucleoside adducts with lipid peroxidation products: Vertical (VIP), adiabatic ionisation potential (AIP), NE: non-equilibrates, EQ: equilibrated solvent-solute interactions, calculated at the M062x/6-31+\(\epsilon\)** level of theory in the aqueous phase. The raw data are given in the Supplementary Materials, Table S1. nitrogen species act as guards, protecting the stability of a cell's physiology and genetic information. It has been established that \(\sim\)9 \(\times\) 10\({}^{4}\) DNA damage events in each human cell are caused over 24 h [40; 41]. To date, more than 80 types of DNA lesions have been identified. The human nuclear diploid genome length consists of an estimated 6.27 \(\times\) 10\({}^{9}\) base pairs for male cells and 6.37 \(\times\) 10\({}^{9}\) for female cells, corresponding to 6.41 pg and 6.51 pg, respectively [42]. However, the pool of nucleobases in a cell is increased by free nucleosides in the cytosol. The following concentrations, in uM, have been found for ribonucleotides: ATP: 3152, GTP: 468, UTP: 567, and CTP: 278. For 2\({}^{\prime}\)-deoxynucleotides, they are dATP: 24, dGTP: 5.2, dCTP: 29, dTTP: 37 [43]. Previous studies have established that guanosine exhibits the lowest ionisation potential (IP) of all the nucleobases and is easily converted by one-electron oxidation to 8-oxo-G, with subsequent decreases in IP values. The following reduction potentials have been noted: 1.29 V and 0.74 V, respectively [44; 45]. This is an indication of their protective role, which is typical of antioxidants. Based on the above, this article has considered the changes in ionisation potential following DNA damage formation by PLO products.