Determination of the ionization constants of 4-iodo-2,6-dimethylphenylcarbamoylmethyl iminodiacetic acid.
In order to develop a radiopharmaceutical for hepatobiliary scintigraphy with better hepatobiliary properties new ligand for complexation of 99mTc, 4-iodo-2,6-dimethylphenylcarbamoylmethyl iminodiacetic acid (METHYLIODIDA), was synthesized. Acid-base equilibria of METHYLIODIDA were studied potentiometrically, because these data are important for determination of complex formation conditions. It was established that METHYLIODIDA undergoes a complex acid-base equilibrium due to its zwitterionic nature and four proton-binding sites. The stoichiometric ionization constants were determined at 25 degrees C and constant ionic strength 0.1M (NaClO(4)): pK1=1.7+/-0.1; pK2=2.44+/-0.07; pK3=6.29+/-0.02 and pK4=10.91+/-0.06, respectively.
Jovanović
M S
MS
Laboratory for Radioisotopes, Institute of Nuclear Sciences Vinca, P.O. Box 522, 11000 Belgrade, Serbia and Montenegro.
Popović
G
G
Kapetanović
V
V
Orlić
M
M
Vladimirov
S
S
D002626:Chemistry, Pharmaceutical; D006863:Hydrogen-Ion Concentration; D007098:Imino Acids / Q000737:chemistry*; D008956:Models, Chemical; D015394:Molecular Structure; D011199:Potentiometry
C496832:4-iodo-2,6-dimethylphenylcarbamoylmethyl iminodiacetic acid; D007098:Imino Acids; C008109:iminodiacetic acid