K. Farah et N. Farouk, COPPER-CATALYZED RADIOIODINATION OF 3-IODOTYROSINE AND 4-IODOPHENYL ALANINE, Journal of labelled compounds & radiopharmaceuticals, 39(11), 1997, pp. 915-926
Citations number
26
Categorie Soggetti
Chemistry Analytical","Pharmacology & Pharmacy","Biochemical Research Methods
The factors affecting the yield of the copper catalyzed labelling of 3
-iodotyrosine and 4-iodophenyl alanine such as pH of the medium, catal
yst and substrate concentrations and solvent effects are described. Th
e reaction is assumed to take place via an intermediate organo-copper
complex which favours the exchange between radioiodine and the inactiv
e iodine in the iodocompound. The reducing agents ascorbic acid, stann
ous chloride or sodium metabisulphite are added to the cuprous chlorid
e catalyzed reaction to prevent the oxidation of Cu (I) to Cu (II) in
order to decrease side products formation and improve the labelling yi
eld. Kinetics indicated a second order reaction with an activation ene
rgy of 9.6 Kcal/mole for 3-iodotyrosine and 12.2 Kcal/mole for 4-iodop
henyl alanine. The stronger 4-iodophenyl C-l bond favours para-iodinat
ion in the preparation of radioiodinated monoclonal antibodies.