Determination of the ionization constants of 4-iodo-2,6-dimethylphenylcarbamoylmethyl iminodiacetic acid

M S Jovanović; G Popović; V Kapetanović; M Orlić; S Vladimirov

doi:10.1016/j.jpba.2004.03.009

Determination of the ionization constants of 4-iodo-2,6-dimethylphenylcarbamoylmethyl iminodiacetic acid

J Pharm Biomed Anal. 2004 Sep 3;35(5):1257-61. doi: 10.1016/j.jpba.2004.03.009.

Authors

M S Jovanović¹, G Popović, V Kapetanović, M Orlić, S Vladimirov

Affiliation

¹ Laboratory for Radioisotopes, Institute of Nuclear Sciences Vinca, P.O. Box 522, 11000 Belgrade, Serbia and Montenegro.

PMID: 15336370
DOI: 10.1016/j.jpba.2004.03.009

Abstract

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.

MeSH terms

Chemistry, Pharmaceutical
Hydrogen-Ion Concentration
Imino Acids / chemistry*
Models, Chemical
Molecular Structure
Potentiometry

Substances

4-iodo-2,6-dimethylphenylcarbamoylmethyl iminodiacetic acid
Imino Acids
iminodiacetic acid