ABSTRACT
A series of esters of 1,4-disubstituted tetrahydropyridine carboxylic acids (I) has been synthesized and characterized as potential m1 selective muscarinic receptor antagonists. The affinity of these compounds for the five human muscarinic receptor subtypes (Hm1-Hm5) was determined by the displacement of [3H]-NMS binding using membranes from transfected Chinese hamster ovarian cells. One of the most potent and selective compounds of this series is an analogue of I [11, R1 = (CH2)5CH3], which has an IC50 value of 27.3 nM at the m1 receptor and possesses 100-fold (m2), 48-fold (m3), 74-fold (m4), and 19-fold (m5) selectivities at the other receptors. Thus, this analogue appears to be more selective on the basis of binding than the prototypical m1 antagonist, pirenzepine. Functional data, such as the inhibition of carbachol-stimulated phosphatidylinositol hydrolysis, on selected analogues confirmed the muscarinic antagonistic properties of this chemical series.
Subject(s)
Muscarinic Antagonists/chemistry , Animals , CHO Cells , Cricetinae , Humans , Magnetic Resonance Spectroscopy , Mass Spectrometry , Molecular Structure , Muscarinic Antagonists/classification , Muscarinic Antagonists/pharmacology , Structure-Activity RelationshipABSTRACT
Our interest in the area of m4 muscarinic antagonists had led us to study a series of benzoxazine isoquinolines. One of the most potent and selective compounds of this series is example 1 with an IC50 value of 90.7 nM at m4 receptors, and 72-fold (m1), 38-fold (m2), 10-fold (m3), and 82-fold (m5) more selective compared to the other receptors. The synthesis and receptor binding affinity of analogs of 1 are reported.
Subject(s)
Isoquinolines/chemistry , Muscarinic Antagonists/chemistry , Receptors, Muscarinic/drug effects , Isoquinolines/metabolism , Isoquinolines/pharmacology , Muscarinic Antagonists/metabolism , Muscarinic Antagonists/pharmacology , Protein Binding , Receptor, Muscarinic M4 , Receptors, Muscarinic/metabolismABSTRACT
Peptidomimetic inhibitors of general structure 1 have been prepared. Optimization of the binding affinities of these compounds through variation of the P3 hydrophobic residue is described. Selected substituted bicylic lactams displayed interesting pharmacological profiles both in vitro and in vivo.