Ionic effects on some anticancer drugs from analysis of their metal ion and proton affinities

The proton affinities (PA) and the metal ion affinities (MA) of nitrogen mustards have been investigated to analyze the ionic effect in alkylation reactions. The ion affinities of N4 atomic site of nitrogen mustards are significant, and the proton affinities are more significant than the metal ion affinities. However, Na + affinities are comparatively less than Mg 2+ affinities. The values of ion affinities have been taken for comparing the ionic effect in alkylation reaction. The magnitudes of PA and MA (Mg 2+ ) indirectly show the possibility of inhibitory effect at the intermediate state during aziridinium ion formation of alkylation reaction. So, the presence of H + and Mg 2+ may change the alkylation rate, since these ions acquire strong affinity for N4 of nitrogen mustards.