Potentiometric and spectrophotometric determination of the dissociation constants of mesatone and epinephrine

Abstract

The dissociation constants of proton-acceptor and-donor groups of adrenaline (epinephrine) and mesatone were determined by potentiometric and spectrophotometric titration method. The potentiometric titration data were used to calculate the protonation constants of a secondary amino group in each drug, and the spectrophotometric titration data were used to determine the dissociation constants of OH groups influencing the distribution of electron density in the chromophore (aromatic system). Once the dissociation constants are known, the distributions of the ionized forms of epinephrine and mesatone at various Open image in new window H can be calculated. In these calculations, it is important to take into consideration the transport of biologically active molecules through membranes and their interactions with receptors.