Design, synthesis and biological evaluation of naphthalimide-based fluorescent probes for α1-adrenergic receptors.

α1-Adrenergic receptors (α1-ARs), as one of the most important members of G protein-coupled receptors (GPCRs), can mediate lots of physiological responses of the sympathetic nervous system. Until now, α1-ARs have been divided into at least three subtypes, α1A, α1B, and α1D, which distribute in various tissues and organs. In this research, we designed and synthesized several napthalimide-based small-molecule fluorescent probes for α1-ARs, which mainly contained two parts: the pharmacophore (quinazoline and phenylpiperazine) that binds to α1-ARs and the fluorophore (naphthalimide) that labels the receptors with fluorescent properties. Moreover, some of these compounds demonstrated potent affinity to α1-ARs and cell imaging potential.