Premium
Biological evaluation and comparison of three different procedures for labelling of amino acids tyrosine and lysine with technetium‐99m
Author(s) -
Djokić D.,
Janković D.
Publication year - 2007
Publication title -
journal of labelled compounds and radiopharmaceuticals
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.432
H-Index - 47
eISSN - 1099-1344
pISSN - 0362-4803
DOI - 10.1002/jlcr.1205
Subject(s) - labelling , chemistry , tyrosine , amino acid , chelation , yield (engineering) , lysine , denticity , technetium , technetium 99m , radiochemistry , stereochemistry , biochemistry , nuclear chemistry , organic chemistry , scintigraphy , nuclear medicine , medicine , materials science , crystal structure , metallurgy
The 99m Tc‐labelling of the amino acids tyrosine (Tyr) and lysine (Lys), fundamental building blocks of proteins and peptides, as well as biological properties of the labelled compounds are investigated. Three different approaches for the labelling with 99m Tc have been investigated: direct reduction with stannous tin in the presence of the amino acids, the preformed chelate approach through polydentate chelates DTPA and GH, and the ‘organometallic approach’ using [ 99m Tc(CO) 3 (H 2 O) 3 ] + precursor. The direct labelling approach was not successful and the yield was poor. In the presence of DTPA and GH, the labelling efficiency was between 43.6 and 97.8%, depending on the amino acid and the polydentate chelate. The use of [ 99m Tc(CO) 3 (H 2 O) 3 ] + precursor point at the formation of 99m Tc(I) co‐ordinated complexes with high yield. In this approach, pH and heating influenced the yields. The results of organ distribution study for [ 99m Tc(Tyr)(H 2 O)(CO) 3 ] and [ 99m Tc(Lys)(H 2 O)(CO) 3 ] show accumulation in liver, kidneys and intestine. Copyright © 2007 John Wiley & Sons, Ltd.