Design, Synthesis And Biological Evaluation Of Small-molecule Fluorescent Probes For α₁-adrenergic Receptors

The α1-adrenergic receptors (α1-ARs) are one of the most important members of G protein-coupled receptors (GPCRs) in varieties of cells, tissues and organs. They are also essential mediators of the sympathetic nervous system, which mediate many vital physiological effects in the human body and are related with a variety of diseases, such as hypertension and prostate diseases. Therefore, to understand the pharmacological and pathological characteristics of α1-adrenergic receptors is of great importance in pathogenesis research, clinical diagnosis and treatment of diseases.The current thesis includes the synthesis and bioactivity study of small-molecule fluorescent probes for α1-adrenergic receptors. There are mainly five parts in this thesis:Ⅰ. Preface; Ⅱ. The design of fluorescent probes; Ⅲ. The synthesis of the fluorescent probes; Ⅳ. The biological evaluation of the fluorescent probes; V. summary and outlook.The first part is about the research background of the α1-adrenergic receptors, the principle of small-molecule fluorescent probes, the influence factors of fluorescence intensity and the application prospect of fluorescent probes.In part Ⅱ, we talked about the design of the fluorescent probes for α1-adrenergic receptors. Based on our previous research and the α1-adrenergic receptors antagonist pharmacophores, we chose phenylpiperazine and quinazoline as the pharmacophore, and fluorescein and naphthalimide as the fluorophore, to design fluorescent probes for α1-adrenergic receptors.In chapter Ⅲ, through Claisen rearrangement, Mannich reaction, Gabriel reaction, nucleophilic addition and elimination reaction, we synthesized the probes for α1-adrenergic receptors.In the biological evaluation part, the optical properties, affinity test, fluorescence imaging and cytotoxicity evaluation were well measured. The experimental results demonstrated that the synthetic probes displayed well optical properties, high affinity to three subtypes of α1-adrenergic receptors, reasonable fluorescence imaging ability and low cytotoxicity.In chapter V, based on our research, we synthesized selective fluorescent probes for α1-adrenergic receptors that can label the receptors in living cells. The results provided a solid foundation for further structural modification, looking forward to discover the ideal fluorescent probes for α1-adrenergic receptors. Besides, because of the high affinity to α1-adrenergic receptors, the synthetic probes can be employed as competitive substrates for screening α1-adrenergic receptors antagonists based on the fluorescent properties. Due to the convenient and easy to handle advantages, it will replace the current widely use of radio ligand binding assay.