Interaction of cis-(6-benzhydrylpiperidin-3-yl)benzylamine analogues with monoamine transporters: structure-activity relationship study of structurally constrained 3,6-disubstituted piperidine analogues of (2,2-diphenylethyl)-[1-(4-fluorobenzyl)piperidin-4-ylmethyl]amine.
To explore structure-activity relationships (SAR) of a novel conformationally constrained lead cis-3,6-disubstituted piperidine derivative derived from (2,2-diphenylethyl)-[1-(4-fluorobenzyl)piperidine-4-ylmethyl]amine (I), a series of compounds was synthesized by derivatizing the exocyclic N-atom at the 3-position of the lead. This study led to the formation of substituted phenyl and heterocyclic derivatives. All novel compounds were tested for their affinity at the dopamine transporter (DAT), serotonin transporter (SERT), and norepinephrine transporter (NET) in the brain by measuring their potency in competing for the binding of [3H]WIN 35 428, [3H]citalopram, and [3H]nisoxetine, respectively. Selected compounds were also evaluated for their activity in inhibiting the uptake of [3H]DA. The SAR results demonstrated that the nature of substitutions on the phenyl ring is important in activity at the DAT with the presence of an electron-withdrawing group having the maximum effect on potency. Replacement of the phenyl ring in the benzyl group by heterocyclic moieties resulted in the development of compounds with moderate activity for the DAT. Two most potent racemic compounds were separated by a diastereoisomeric separation procedure, and differential affinities were observed for the enantiomers. Absolute configuration of the enantiomers was obtained unambiguously by X-ray crystal structural study. One of the enantiomers, compound S,S-(-)-19a, exhibited the highest potency for the DAT (IC50 = 11.3 nM) among all the compounds tested and was as potent as GBR 12909 (1-[2-[bis(4-fluorophenyl)methoxy]ethyl]-4-(3-phenylpropyl)piperazine). However, the compound (-)-19a was more selective than GBR 12909 in binding to the DAT compared with binding to the SERT and NET. The present results establish the newly developed 3,6-disubstituted piperidine derivatives as a novel template for high-affinity inhibitors of DAT. Structurally these molecules are more constrained compared to our earlier flexible piperidine molecules and, thus, should provide more insights about their bioactive conformations.
Kolhatkar
Rohit B
RB
Wayne State University, Department of Pharmaceutical Sciences, Detroit, Michigan 48202, USA.
Ghorai
Sujit K
SK
George
Clifford
C
Reith
Maarten E A
ME
Dutta
Aloke K
AK
D000818:Animals; D001667:Binding, Competitive; D015306:Biogenic Monoamines / Q000378:metabolism*; D001692:Biological Transport; D001921:Brain / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism*; D018360:Crystallography, X-Ray; D050483:Dopamine Plasma Membrane Transport Proteins; D066298:In Vitro Techniques; D008562:Membrane Glycoproteins / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000378:metabolism*; D008968:Molecular Conformation; D009419:Nerve Tissue Proteins; D009570:Nitriles / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D050484:Norepinephrine Plasma Membrane Transport Proteins; D010879:Piperazines / Q000737:chemistry / Q000494:pharmacology; D010880:Piperidines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D011869:Radioligand Assay; D051381:Rats; D050486:Serotonin Plasma Membrane Transport Proteins; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D027981:Symporters / Q000378:metabolism*
C474827:(2,2-diphenylethyl)-(1-(4-fluorobenzyl)piperidine-4-ylmethyl)amine; C474826:4-((6-benzhydrylpiperidin-3-ylamino)methyl)benzonitrile; D015306:Biogenic Monoamines; D002352:Carrier Proteins; D050483:Dopamine Plasma Membrane Transport Proteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D009570:Nitriles; D050484:Norepinephrine Plasma Membrane Transport Proteins; D010879:Piperazines; D010880:Piperidines; D050486:Serotonin Plasma Membrane Transport Proteins; C493226:Slc6a2 protein, rat; C493216:Slc6a3 protein, rat; C493232:Slc6a4 protein, rat; D027981:Symporters; C043425:vanoxerine