Summary: The halogenated fluorescein derivatives: 2”,4”,5”,7′-tetrabromofluorescein isothiocyanate dextran (BrFD) and 4”,5′-diiodofluorescein isothiocyanate dextran (IFD), were found to be efficient photosensitizers for the production of singlet oxygen. The singlet oxygen quantum yields were determined by reaction with acceptors in aqueous solution. Their comparison showed that the singlet oxygen quantum yield of BrFD was threefold higher than that of IFD. BrFD was more resistant to photobleaching than IFD. Both derivatives were internalized by fluid-phase pinocytosis in amoebae of the cellular slime mould . Subsequently, illumination of cells led to a dose-dependent loss of viability consistent with a role for singlet oxygen generated inside the endosomal compartments in the mechanism of photoinjury. BrFD showed a three-fold higher efficiency than IFD for photoinduced cytotoxicity.


Article metrics loading...

Loading full text...

Full text loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error