TY - JOUR
T1 - Synthesis and characterization of fluorinated and iodinated pyrrolopyrimidines as PET/SPECT ligands for the CRF1 receptor
AU - Martarello, Laurent
AU - Kilts, Clinton D.
AU - Ely, Timothy
AU - Owens, Michael J.
AU - Nemeroff, Charles B.
AU - Camp, Mel
AU - Goodman, Mark M.
PY - 2001
Y1 - 2001
N2 - Fluorine-18 labeled fluorobutyl[2,5-dimethyl-7-(2,4,6-trimethylphenyl)-7H-pyrrolo [2,3-d] pyrimidin-4-yl]ethylamine (FBPPA) and iodine-123 labeled butyl[2,5-dimethyl-7-(4-iodo-2,6-dimethylphenyl)-7H-pyrrolo[2,3-d] pyrimidin-4-yl]ethyl-amine (IBPPA) were synthesized in the development of a CRF receptor ligand. The methods of synthesis, in vitro binding assays, radiolabeling and in vivo tissue distribution in rats are described. Fluorine-18 labeled FBPPA was prepared with high specific activity (3 × 104 Ci/mmol) by nucleophilic displacement with an average radiochemical yield of 6% (EOB). Iodine-123 labeled IBPPA was prepared by electrophilic iododestannylation with good yield (60%) and high specific activity (3.3 × 103 Ci/mmol). The retention of FBPPA and IBPPA in the pituitary was good (1.16% i.d./g and 2.35% i.d./g respectively at 60 min). However, the accumulation of radioactivity in the brain for both radiotracers was very low at all time points of the study, which demonstrated the difficulties for these radiopharmaceuticals to penetrate the blood brain barrier (BBB).
AB - Fluorine-18 labeled fluorobutyl[2,5-dimethyl-7-(2,4,6-trimethylphenyl)-7H-pyrrolo [2,3-d] pyrimidin-4-yl]ethylamine (FBPPA) and iodine-123 labeled butyl[2,5-dimethyl-7-(4-iodo-2,6-dimethylphenyl)-7H-pyrrolo[2,3-d] pyrimidin-4-yl]ethyl-amine (IBPPA) were synthesized in the development of a CRF receptor ligand. The methods of synthesis, in vitro binding assays, radiolabeling and in vivo tissue distribution in rats are described. Fluorine-18 labeled FBPPA was prepared with high specific activity (3 × 104 Ci/mmol) by nucleophilic displacement with an average radiochemical yield of 6% (EOB). Iodine-123 labeled IBPPA was prepared by electrophilic iododestannylation with good yield (60%) and high specific activity (3.3 × 103 Ci/mmol). The retention of FBPPA and IBPPA in the pituitary was good (1.16% i.d./g and 2.35% i.d./g respectively at 60 min). However, the accumulation of radioactivity in the brain for both radiotracers was very low at all time points of the study, which demonstrated the difficulties for these radiopharmaceuticals to penetrate the blood brain barrier (BBB).
KW - CRF receptor
KW - Fluorine-18
KW - Iodine-123
KW - Radiolabeling
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U2 - 10.1016/S0969-8051(00)00199-2
DO - 10.1016/S0969-8051(00)00199-2
M3 - Article
C2 - 11295429
AN - SCOPUS:0035057666
VL - 28
SP - 187
EP - 195
JO - International journal of radiation applications and instrumentation. Part B, Nuclear medicine and biology
JF - International journal of radiation applications and instrumentation. Part B, Nuclear medicine and biology
SN - 0969-8051
IS - 2
ER -