Table shows a fair agreement between the simulated and experimental ΔΔG values in qualitative terms. First, we discuss the two significant outliers where ΔΔGsim is positive, while ΔΔGexp is negative (MTF@MOR: -12.90/3.57 kcal/mol; MTF@MFI: -12.01/2.97 kcal/mol, see Table ). This disagreement can be explained by looking at the molecular structure of Metformin (MTF) (see Figure ). . The equilibrium in aqueous solution is strongly shifted to the protonated form.