Synthesis and preliminary analysis of a P-glycoprotein-specific [3H]-benzophenone photoaffinity label based on (−)-stipiamide

A benzophenone photoaffinity label 9 based on the polyene natural product (−)-stipiamide has been constructed using a diaminoethane spacer and the radioactive agent [3H]-BZDC (N-succinimidyl p-benzoyl-(2,3-3H)-dehydrocinnamate). Photoaffinity experiments show specific binding to human P-glycoprotein (Pgp) in the presence of cis-flupentixol but not with cyclosporin A.