A hybrid molecule of a GFP chromophore analogue and cholestene as a viscosity-dependent and cholesterol-responsive fluorescent sensor.

Diarylmethylenated and cholestene (or -tane)-hybrid analogues of the GFP chromophore, namely, Ch-DAINs were successfully synthesised by a condensation reaction between methyl imidates and N-(diarylmethylene)glycinates. Among the Ch-DAINs synthesised, a diphenyl-type analogue showed viscosity-dependent and cholesterol-responsive fluorescent properties. It showed a nearly linear increase of the fluorescence emission in triglycerides and vesicles as the amount of cholesterol was increased.