PURPOSE: We have studied the utility of [(18)F]ClF electrophilic addition to the carbon-carbon double bond of analogues of a model positron emission tomography (PET) tracer, [(18)F]EF5. The consequence of simultaneous chlorine/fluorine addition on lipophilicity and biological activity of the molecule is evaluated. PROCEDURES: Post-target produced [(18)F]F2 was reacted with Cl2 to produce [(18)F]ClF, which was used in electrophilic addition. RESULTS: [(18)F]ClF was produced and used to label chlorinated analogues of [(18)F]EF5. The chlorinated analogues, [(18)F]EF4Cla and [(18)F]EF4Clb, were synthesized simultaneously. The in vivo uptake of the analogues compared well with [(18)F]EF5 uptake in tumor-bearing mice. CONCLUSION: [(18)F]ClF is a suitable labeling reagent for electrophilic addition to double bonds of PET tracers. The results show that the modification of the pentafluoro group of [(18)F]EF5 by monofluorine-for-chlorine exchange affected the lipophilicity, but the hypoxia avidity of these molecules was not apparently altered.
PURPOSE: We have studied the utility of [(18)F]ClF electrophilic addition to the carbon-carbon double bond of analogues of a model positron emission tomography (PET) tracer, [(18)F]EF5. The consequence of simultaneous chlorine/fluorine addition on lipophilicity and biological activity of the molecule is evaluated. PROCEDURES: Post-target produced [(18)F]F2 was reacted with Cl2 to produce [(18)F]ClF, which was used in electrophilic addition. RESULTS:[(18)F]ClF was produced and used to label chlorinated analogues of [(18)F]EF5. The chlorinated analogues, [(18)F]EF4Cla and [(18)F]EF4Clb, were synthesized simultaneously. The in vivo uptake of the analogues compared well with [(18)F]EF5 uptake in tumor-bearing mice. CONCLUSION:[(18)F]ClF is a suitable labeling reagent for electrophilic addition to double bonds of PET tracers. The results show that the modification of the pentafluoro group of [(18)F]EF5 by monofluorine-for-chlorine exchange affected the lipophilicity, but the hypoxia avidity of these molecules was not apparently altered.
Authors: T Grönroos; O Eskola; K Lehtiö; H Minn; P Marjamäki; J Bergman; M Haaparanta; S Forsback; O Solin Journal: J Nucl Med Date: 2001-09 Impact factor: 10.057
Authors: Gaber Komar; Marko Seppänen; Olli Eskola; Paula Lindholm; Tove J Grönroos; Sarita Forsback; Hannu Sipilä; Sydney M Evans; Olof Solin; Heikki Minn Journal: J Nucl Med Date: 2008-11-07 Impact factor: 10.057