Determination of Dissociation Constants of FLT3 Inhibitor CHMFL-FLT3-122

OBJECTIVE To determine the two dissociation constants of CHMFL-FLT3-122.METHODS Dissolve CHMFL-FLT3-122 in a series of different pH values buffer solutions and the absorbance was measured at appropriate wavelengths by UV to calculate the pK_a1.Different proportions of acetonitrile-water mixtures (30:70,40:60,50:50,60:40) were used to prepare different concentrations of CHMFL-FLT3-122 solutions (0.009,0.013,0.017 mol·L^-1) which were titrated by hydrochloric acid solution and the pK_a2 was calculated by non-logarithmic titration method (Benet method).RESULTS The pK_a1 of CHMFL-FLT3-122 was 3.87±0.14 and the pK_a2 of CHMFL-FLT3-122 was 8.12.CONCLUSION The determination of the dissociation constants of CHMFL-FLT3-122 by UV and Non-logarithmic titration method is simple,rapid,accurate and reliable.It can be a reference for the prescription design of preparations and the research of quality standard.