Abstract
2-[(Diphenylmethyl)sulfinyl]acetamide (modafinil, (±)-1) is a unique dopamine uptake inhibitor that binds the dopamine transporter (DAT) differently than cocaine and may have potential for the treatment of psychostimulant abuse. To further investigate structural requirements for this divergent binding mode, novel thio- and sulfinylacetamide and ethanamine analogues of (±)-1 were synthesized wherein (1) the diphenyl rings were substituted with methyl, trifluoromethyl, and halogen substituents and (2) substituents were added to the terminal amide/amine nitrogen. Halogen substitution of the diphenyl rings of (±)-1 gave several amide analogues with improved binding affinity for DAT and robust selectivity over the serotonin transporter (SERT), whereas affinity improved at SERT over DAT for the p-halo-substituted amine analogues. Molecular docking studies, using a subset of analogues with DAT and SERT homology models, and functional data obtained with DAT (A480T) and SERT (T497A) mutants defined a role for TM10 in the substrate/inhibitor S1 binding sites of DAT and SERT.
Publication types
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Research Support, N.I.H., Intramural
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Benzhydryl Compounds / chemical synthesis*
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Benzhydryl Compounds / chemistry
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Benzhydryl Compounds / pharmacology
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Binding Sites
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Brain / metabolism
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COS Cells
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Chlorocebus aethiops
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Dopamine Plasma Membrane Transport Proteins / chemistry
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Dopamine Plasma Membrane Transport Proteins / genetics
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Dopamine Plasma Membrane Transport Proteins / metabolism*
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Male
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Modafinil
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Molecular Docking Simulation
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Mutation
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Norepinephrine Plasma Membrane Transport Proteins / chemistry
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Norepinephrine Plasma Membrane Transport Proteins / genetics
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Norepinephrine Plasma Membrane Transport Proteins / metabolism*
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Protein Binding
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Radioligand Assay
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Rats
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Rats, Sprague-Dawley
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Serotonin Plasma Membrane Transport Proteins / chemistry
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Serotonin Plasma Membrane Transport Proteins / genetics
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Serotonin Plasma Membrane Transport Proteins / metabolism*
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Stereoisomerism
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Structure-Activity Relationship
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Thioacetamide / analogs & derivatives
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Thioacetamide / chemical synthesis
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Thioacetamide / chemistry
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Thioacetamide / pharmacology
Substances
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Benzhydryl Compounds
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Dopamine Plasma Membrane Transport Proteins
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Norepinephrine Plasma Membrane Transport Proteins
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Serotonin Plasma Membrane Transport Proteins
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Thioacetamide
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Modafinil