Computer programs for calculating pK_a: a comparative study for 3-(3-(2-nitrophenyl)prop-2-enoyl)-2H-1-benzopyran-2-one

摘要

Coumarin-based compounds containing a chalcone moiety exhibit antimicrobial activity. These substances are potential drugs and it is important to determine their pK_a values. However, they are almost insoluble in water. The dissociation constant was experimentally determined by potentiometric titration for 3-[3-(2-nitrophenyl)prop-2-enoyl]-2H-1-benzopyran-2-one because this compound shows good activity and solubility. A number of different computer programs for the calculation of the dissociation constant of chemical compounds have been developed. The pA_a value of the target compound was calculated using three different computer programs, i.e., the ACD/pK_a, CSpKaPredictor and ADME/ToxWEB programs, which are based on different theoretical approaches. The analysis demonstrated good agreement between the experimentally observed pK_a value of 3-[3-(2-nitrophenyl)prop-2-enoyl]-2H-1-benzopy-ran-2-one and the value calculated using the computer program CSpKa.