Synthesis and characterization of high-affinity 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene-labeled fluorescent ligands for human β-adrenoceptors

J Med Chem. 2011 Oct 13;54(19):6874-87. doi: 10.1021/jm2008562. Epub 2011 Sep 16.

Abstract

The growing practice of exploiting noninvasive fluorescence-based techniques to study G protein-coupled receptor pharmacology at the single cell and single molecule level demands the availability of high-quality fluorescent ligands. To this end, this study evaluated a new series of red-emitting ligands for the human β-adrenoceptor family. Upon the basis of the orthosteric ligands propranolol, alprenolol, and pindolol, the synthesized linker-modified congeners were coupled to the commercially available fluorophore BODIPY 630/650-X. This yielded high-affinity β-adrenoceptor fluorescent ligands for both the propranolol and alprenolol derivatives; however, the pindolol-based products displayed lower affinity. A fluorescent diethylene glycol linked propranolol derivative (18a) had the highest affinity (log K(D) of -9.53 and -8.46 as an antagonist of functional β2- and β1-mediated responses, respectively). Imaging studies with this compound further confirmed that it can be employed to selectively label the human β2-adrenoceptor in single living cells, with receptor-associated binding prevented by preincubation with the nonfluorescent β2-selective antagonist 3-(isopropylamino)-1-[(7-methyl-4-indanyl)oxy]butan-2-ol (ICI 118551) ( J. Cardiovasc. Pharmacol.1983, 5, 430-437. ).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adrenergic beta-Agonists / chemical synthesis
  • Adrenergic beta-Agonists / chemistry
  • Adrenergic beta-Agonists / pharmacology
  • Adrenergic beta-Antagonists / chemical synthesis
  • Adrenergic beta-Antagonists / chemistry
  • Adrenergic beta-Antagonists / pharmacology
  • Alprenolol / analogs & derivatives
  • Alprenolol / chemical synthesis
  • Alprenolol / chemistry
  • Alprenolol / pharmacology
  • Animals
  • Boron Compounds / chemical synthesis*
  • Boron Compounds / chemistry
  • Boron Compounds / pharmacology
  • CHO Cells
  • Cricetinae
  • Cricetulus
  • Drug Partial Agonism
  • Fluorescent Dyes / chemical synthesis*
  • Fluorescent Dyes / chemistry
  • Fluorescent Dyes / pharmacology
  • Genes, Reporter
  • Humans
  • Ligands
  • Microscopy, Confocal
  • Pindolol / analogs & derivatives
  • Pindolol / chemical synthesis
  • Pindolol / chemistry
  • Pindolol / pharmacology
  • Propranolol / analogs & derivatives
  • Propranolol / chemical synthesis
  • Propranolol / chemistry
  • Propranolol / pharmacology
  • Radioligand Assay
  • Receptors, Adrenergic, beta-1 / metabolism*
  • Receptors, Adrenergic, beta-2 / metabolism*
  • Receptors, Adrenergic, beta-3 / metabolism*
  • Single-Cell Analysis
  • Stereoisomerism
  • Structure-Activity Relationship

Substances

  • Adrenergic beta-Agonists
  • Adrenergic beta-Antagonists
  • Boron Compounds
  • Fluorescent Dyes
  • Ligands
  • N-(3-hydroxy-1-(naphthalen-1-yl)-1,8,11-trioxa-5-azatridecan-13-yl)-6-(2-(2-(4,4-difluoro-4,4a-dihydro-5-(thiophen-2-yl)-4-bora-3a,4a-diaza-s-indacene-3-yl)vinyl)phenoxyacetamido)hexanamide
  • Receptors, Adrenergic, beta-1
  • Receptors, Adrenergic, beta-2
  • Receptors, Adrenergic, beta-3
  • Alprenolol
  • Propranolol
  • Pindolol