[123I]-Celecoxib Analogues as SPECT Tracers of Cyclooxygenase-2 in Inflammation
摘要:
We report the synthesis and evaluation of a series of iodinated celecoxib analogues as cyclooxygenase-2 (COX-2)-targeted single photon emission computerized tomography (SPECT)-imaging agents for the detection of inflammation. The structure-activity relationship identified 5-(4-iodophenyl)-1-{4-(methylsulfonyl)-phenyl}-3-(trifuloromethyl)-1H-pyrazole (8) as a promising compound with IC50 values of 0.05 mu M against purified COX-2 and 0.03 mu M against COX-2 in activated macrophages. The arylstannane of 8-undergoes facile radio-[I-123]-iodination upon treatment with (NaI)-I-123/NaI and chloramine T using an EtOAc/H2O two-phase system. The [I-123]-8 was produced in a radiochemical yield of 85% and a radiochemical purity of 99%. In vivo SPECT imaging demonstrated that the radiotracer was taken up by inflamed rat paws with an average 1.7-fold enrichment over contralateral noninflamed paws. This study suggests that conversion of celecoxib into its isomeric iodo [I-123]-analogues is a useful approach for generating novel and efficacious agents for COX-2-targeted SPECT imaging of inflammation.
The present invention is directed to compounds of formula I:
Wherein R
1
to R
5
, X and Z are further defined in the description. The invention also relates to processes for the preparation of the compounds and to intermediates used in the preparation, pharmaceutical compositions containing the compounds, and to the use of the compounds in therapy.