5-HT1A- versus D2-Receptor Selectivity of Flesinoxan and Analogous N4-Substituted N1-Arylpiperazines
摘要:
We investigated the structural requirements for high 5-HT1A affinity of the agonist flesinoxan and its selectivity versus D-2 receptors. For this purpose a series of arylpiperazine congeners of flesinoxan were synthesized and evaluated for their ability to displace [H-3]-8-OH-DPAT and [H-3]spiperone from their specific binding sites in rat frontal cortex homogenates and rat striatum, respectively. Variations were made in the N-4-substituent and the arylpiperazine region. Effects of N-4-substitution in the investigated compounds appeared to be quite similar for 5-HT1A- and D-2-receptor affinity. Lipophilicity at a distance of four carbon atoms from the piperazine N-4 atom seems to be the main contributing factor to affinity for both receptors. Our data show that the amide group in the flesinoxan N-4-substituent is unlikely to interact with the 5-HT1A receptor but, instead, acts as a spacer. In contrast to the structure-affinity relationships (SARs) of the N-4-substituents, selectivity for 5-HT1A versus D-2 receptors was gained by the arylpiperazine substitution pattern of flesinoxan. Restriction of flexibility of the N-4-(benzoylamino)ethyl substituent and its effect on 5-HT1A-receptor affinity and activity were also studied. Our data show that in the bioactive conformation, the N-4-[(p-fluorobenzoyl)amino]ethyl substituent is probably directed anti-periplanar relative to the H-N4 atom. These results were used to dock flesinoxan (1) and two of its congeners (27 and 33) into a model of the 5-HT1A receptor that we previously reported. Amino acid residues surrounding the N-4-[(p-fluorobenzoyl)amino]ethyl substituent of flesinoxan and its congeners are also present in D-2 receptors. In contrast, several residues that contact the benzodioxane moiety differ from those in D-2 receptors. These observations from the 3D model agree with the 5-HT1A SAR data and probably account for the selectivity of flesinoxan versus D-2 receptors.
Structure–Kinetic Profiling of Haloperidol Analogues at the Human Dopamine D<sub>2</sub> Receptor
作者:Tim J. Fyfe、Barrie Kellam、David A. Sykes、Ben Capuano、Peter J. Scammells、J. Robert Lane、Steven J. Charlton、Shailesh N. Mistry
DOI:10.1021/acs.jmedchem.9b00864
日期:2019.11.14
a typical antipsychotic drug (APD) associated with an increased risk of extrapyramidal side effects (EPSs) and hyperprolactinemia relative to atypical APDs such as clozapine. Both drugs are dopamine D2 receptor (D2R) antagonists, with contrasting kinetic profiles. Haloperidol displays fast association/slow dissociation at the D2R, whereas clozapine exhibits relatively slow association/fast dissociation
5-HT<sub>1A</sub>- versus D<sub>2</sub>-Receptor Selectivity of Flesinoxan and Analogous <i>N</i> <sup>4</sup>-Substituted <i>N</i> <sup>1</sup>-Arylpiperazines
作者:Wilma Kuipers、Chris G. Kruse、Ineke van Wijngaarden、Piet J. Standaar、Martin Th. M. Tulp、Nora Veldman、Anthony L. Spek、Adriaan P. IJzerman
DOI:10.1021/jm960496o
日期:1997.1.1
We investigated the structural requirements for high 5-HT1A affinity of the agonist flesinoxan and its selectivity versus D-2 receptors. For this purpose a series of arylpiperazine congeners of flesinoxan were synthesized and evaluated for their ability to displace [H-3]-8-OH-DPAT and [H-3]spiperone from their specific binding sites in rat frontal cortex homogenates and rat striatum, respectively. Variations were made in the N-4-substituent and the arylpiperazine region. Effects of N-4-substitution in the investigated compounds appeared to be quite similar for 5-HT1A- and D-2-receptor affinity. Lipophilicity at a distance of four carbon atoms from the piperazine N-4 atom seems to be the main contributing factor to affinity for both receptors. Our data show that the amide group in the flesinoxan N-4-substituent is unlikely to interact with the 5-HT1A receptor but, instead, acts as a spacer. In contrast to the structure-affinity relationships (SARs) of the N-4-substituents, selectivity for 5-HT1A versus D-2 receptors was gained by the arylpiperazine substitution pattern of flesinoxan. Restriction of flexibility of the N-4-(benzoylamino)ethyl substituent and its effect on 5-HT1A-receptor affinity and activity were also studied. Our data show that in the bioactive conformation, the N-4-[(p-fluorobenzoyl)amino]ethyl substituent is probably directed anti-periplanar relative to the H-N4 atom. These results were used to dock flesinoxan (1) and two of its congeners (27 and 33) into a model of the 5-HT1A receptor that we previously reported. Amino acid residues surrounding the N-4-[(p-fluorobenzoyl)amino]ethyl substituent of flesinoxan and its congeners are also present in D-2 receptors. In contrast, several residues that contact the benzodioxane moiety differ from those in D-2 receptors. These observations from the 3D model agree with the 5-HT1A SAR data and probably account for the selectivity of flesinoxan versus D-2 receptors.