ABSTRACT
With the objective to develop a potential 99mTc radiopharmaceutical for imaging the androgen receptor (AR) in prostate cancer, four ligands bearing the same pharmacophore derived from the AR antagonist flutamide were prepared, labeled with 99mTc, and their structures corroborated via comparison with the corresponding stable rhenium analogs. All complexes were obtained with high radiochemical purity. Three of the complexes were highly stable, and, due to their favorable physicochemical properties, were further evaluated using AR-positive and AR-negative cells in culture. All complexes exhibited considerable uptake in AR-positive cells, which could be blocked by an excess of flutamide. The efflux from the cells was moderate. They also showed significantly lower uptakes in AR-negative cells, indicating interactions with the AR receptor. However, the binding affinities were considerably reduced by the coordination to 99mTc, and the complex that exhibited the best biological behavior did not show sufficient specificity towards AR-positive cells.
Subject(s)
Flutamide , Receptors, Androgen , Male , Humans , Flutamide/pharmacology , Diagnostic Imaging , Radiopharmaceuticals/chemistry , Technetium/chemistry , Organotechnetium Compounds/chemistryABSTRACT
A new synthetic route for the quorum sensing signal Autoinducer-2 (AI-2) is described and used for the preparation of [4-13C]-AI-2 starting from [1-13C]-bromoacetic acid. The key step in this process was the enantioselective reduction of an intermediate ketone. This synthesis provides, selectively, both enantiomers of the labelled or unlabelled parent compound, (R) or (S)-4,5-dihydroxypentane-2,3-dione (DPD) and was used for an improved synthesis of [1-13C]-AI-2.
Subject(s)
Homoserine/analogs & derivatives , Lactones/chemical synthesis , Lactones/pharmacology , Optical Phenomena , Quorum Sensing , Cyclization , Homoserine/chemical synthesis , Homoserine/pharmacology , Quorum Sensing/drug effectsABSTRACT
A small library of compounds was prepared by a combination of toluene dioxygenase (TDO)-catalyzed enzymatic dihydroxylation and copper(I)-catalyzed Hüisgen cycloaddition. Some compounds were obtained by coupling an alkyne and a conduritol derivative, while more complex structures were obtained by a double Hüisgen reaction of a dialkyne and two molecules of the cyclitol. The compounds were fully characterized and subjected to preliminary biological screening.
