Conformationally constrained analogues of N-(piperidinyl)-5-(4-chlorophenyl)-1-(2,4- dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (SR141716): design, synthesis, computational analysis, and biological evaluations.

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Citation

Zhang Y, Burgess JP, Brackeen M, Gilliam A, Mascarella SW, Page K, Seltzman HH, Thomas BF

Conformationally constrained analogues of N-(piperidinyl)-5-(4-chlorophenyl)-1-(2,4- dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (SR141716): design, synthesis, computational analysis, and biological evaluations.

J Med Chem. 2008 Jun 26;51(12):3526-39. doi: 10.1021/jm8000778.

PubMed ID
18512901 [ View in PubMed
]
Abstract

Structure-activity relationships (SARs) of 1 (SR141716) have been extensively documented, however, the conformational properties of this class have received less attention. In an attempt to better understand ligand conformations optimal for receptor recognition, we have designed and synthesized a number of derivatives of 1, including a four-carbon-bridged molecule (11), to constrain rotation of the diaryl rings. Computational analysis of 11 indicates approximately 20 kcal/mol energy barrier for rotation of the two aryl rings. NMR studies have determined the energy barrier to be approximately 18 kcal/mol and suggested atropisomers could exist. Receptor binding and functional studies with these compounds displayed reduced affinity and potency when compared to 1. This indicates that our structural modifications either constrain the ring systems in a suboptimal orientation for receptor interaction or the introduction of steric bulk leads to disfavored steric interactions with the receptor, and/or the relatively modest alterations in the molecular electrostatic potentials results in disfavored Coulombic interactions.

DrugBank Data that Cites this Article

Binding Properties
DrugTargetPropertyMeasurementpHTemperature (°C)
RimonabantCannabinoid receptor 1Ki (nM)6.18N/AN/ADetails
RimonabantCannabinoid receptor 1Ki (nM)1.18N/AN/ADetails