DERIVATIVES OF 4-STYRYLPYRIDINES - SYNTHESIS, ESTROGEN-RECEPTOR BINDING-AFFINITY, AND PHOTOPHYSICAL PROPERTIES

In order to develop novel ligands for the estrogen receptor (ER) that might have high binding affinity and fluorescence properties suitable for assaying ER levels in cells, we have prepared a series of substitu ted 4'-hydroxyl-styrylpyridines and phenylethylpyridines and studied t heir optical spectroscopy and receptor binding properties. Several der ivatives that contain alkyl substituents on the internal ethene or eth ane carbons were prepared. While most of these compounds have only mod est affinity for ER, one fluorescent analog, 1-(4-hydroxyphenyl)-1-phe nyl-2-(4-pyridinyl)ethene (13), has reasonably good binding affinity f or ER and shows long wavelength fluorescence emission that is sensitiv e to solvent polarity and pH. This compound may prove to be a useful p robe for detecting ER in cells.