A first-principle DFT study of solvent effects on metiamide tautomers and imaginary interactions with H2-receptors

Metiamide is a class of medications called H-2-receptor antagonist or H-2 blockers. It decreases the amount of acid made in the stomach. It is commonly used in the treatment for peptic ulcer disease and gastroesophageal reflux disease. In this study, the metiamide tautomer stability, structural data, HOMO and LUMO (energies and shapes), Delta I center dot (HOMO-LUMO) gaps, UV-visible data and graphs, dipole moments, Mulliken charges, and thermodynamic and kinetic stabilities in aqueous media as a biological solvent and some of the different media (vacuum, H2O, Et-OH and DMSO) were investigated for the tautomers of metiamide by the density functional theory DFT-B3LYP/6-31G* method. The results presented that the probability of the adaptability and compatibility of which tautomer (T1-T6) are better than the other tautomers for interactions with the pattern and structural map of the H-2-receptor. The diversities of the interaction points and mosaic patterns of the T3 and T4 tautomers in H2O media with the imaginary H-2-receptor were investigated.