The solvation of nucleic acid bases

Results in Table 6 suggest that the transfer of a nucleic acid base from the gas phase to aqueous solution is very favorable. However, it does not necessarily mean that nucleic acid bases are hydrophilic, since the widely spred concept of hydrophilicity/hydrophobicity results from the transfer between organic and aqueous environments and not from the transfer between gas phase and water. A clear insight into the problem can be gained by comparing 

Free energies of hydration (kcal/mol) of the N-methylated bases of DNA determined from different methods 

Free energies of solvation in water and chloroform indicate that in general the nucleic acid bases are better solvated in water than in chloroform, but the results are not extremely different. This suggests that the nucleic acid bases have a dual character they bear a large number of polar groups which favor their hydration, but the aromatic cores are probably better solvated in apolar solvents like chloroform. The theoretical results in Tables 6 and 7 agree well 

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