Synthesis and Characterization of Model Compounds for the Neutral Green Fluorescent Protein Chromophore

Abstract

Two new derivatives of the green fluorescent protein (GFP) chromophore each containing a charged substituent (CH 2 CH 2 NH 3 + and CH 2 CH 2 NMe 3 + , respectively) on the imidazol-one ring have been prepared. These compounds are model systems for the neutral GFP chromophore with an unprotonated phenol moiety. The ammonium groups allow for electrospray ionization and the possibility to study the optical properties of the isolated chromophores in the gas phase. A derivative containing a CH 2 CH 2 OH substituent arm was also prepared.