Synthesis and characterization of [125I]2-iodo N-[(S)-{(S)-1-methylpiperidin-2-yl}(phenyl)methyl]3-trifluoromethyl-benzamide as novel imaging probe for glycine transporter 1
摘要:
In this study, 2-iodo substituted 1-methylpiperidin-2-yl benzamide derivatives were synthesized and evaluated as candidate SPECT imaging agents for glycine transporter 1 (GlyT1). In JAR cells, which predominantly express GlyT1, 2-iodo N-[(S)-{(S)-1-methylpiperidin-2-yl}(phenyl) methyl]3-trifluoromethyl-benzamide (5) showed excellent inhibitory activity of [H-3] glycine uptake (IC50 = 2.4 nM). Saturation assay in rat cortical membranes revealed that [I-125] 5 had a single high affinity binding site with a K-d of 1.54 nM and a B-max of 3.40 pmol/mg protein. In vitro autoradiography demonstrated that [I-125]5 showed consistent accumulation with GlyT1 expression. The in vitro binding was greatly inhibited by GlyT1 inhibitors but not by other site ligands, which suggested the high specific binding of [I-125]5 with GlyT1. In the biodistribution and ex vivo autoradiography studies using mice, [I-125]5 showed high blood-brain barrier permeability (1.68-2.17% dose/g at 15-60 min) and similar regional brain distribution pattern with in vitro results. In addition, pre-treatment of GlyT1 ligands resulted in significant decrease of [I-125]5 binding in the GlyT1-rich regions. This preliminary study demonstrated that radio-iodinated 5 is a promising SPECT imaging probe for GlyT1. (C) 2011 Elsevier Ltd. All rights reserved.
Synthesis and characterization of [125I]2-iodo N-[(S)-{(S)-1-methylpiperidin-2-yl}(phenyl)methyl]3-trifluoromethyl-benzamide as novel imaging probe for glycine transporter 1
摘要:
In this study, 2-iodo substituted 1-methylpiperidin-2-yl benzamide derivatives were synthesized and evaluated as candidate SPECT imaging agents for glycine transporter 1 (GlyT1). In JAR cells, which predominantly express GlyT1, 2-iodo N-[(S)-{(S)-1-methylpiperidin-2-yl}(phenyl) methyl]3-trifluoromethyl-benzamide (5) showed excellent inhibitory activity of [H-3] glycine uptake (IC50 = 2.4 nM). Saturation assay in rat cortical membranes revealed that [I-125] 5 had a single high affinity binding site with a K-d of 1.54 nM and a B-max of 3.40 pmol/mg protein. In vitro autoradiography demonstrated that [I-125]5 showed consistent accumulation with GlyT1 expression. The in vitro binding was greatly inhibited by GlyT1 inhibitors but not by other site ligands, which suggested the high specific binding of [I-125]5 with GlyT1. In the biodistribution and ex vivo autoradiography studies using mice, [I-125]5 showed high blood-brain barrier permeability (1.68-2.17% dose/g at 15-60 min) and similar regional brain distribution pattern with in vitro results. In addition, pre-treatment of GlyT1 ligands resulted in significant decrease of [I-125]5 binding in the GlyT1-rich regions. This preliminary study demonstrated that radio-iodinated 5 is a promising SPECT imaging probe for GlyT1. (C) 2011 Elsevier Ltd. All rights reserved.
Synthesis and characterization of [125I]2-iodo N-[(S)-{(S)-1-methylpiperidin-2-yl}(phenyl)methyl]3-trifluoromethyl-benzamide as novel imaging probe for glycine transporter 1
In this study, 2-iodo substituted 1-methylpiperidin-2-yl benzamide derivatives were synthesized and evaluated as candidate SPECT imaging agents for glycine transporter 1 (GlyT1). In JAR cells, which predominantly express GlyT1, 2-iodo N-[(S)-(S)-1-methylpiperidin-2-yl}(phenyl) methyl]3-trifluoromethyl-benzamide (5) showed excellent inhibitory activity of [H-3] glycine uptake (IC50 = 2.4 nM). Saturation assay in rat cortical membranes revealed that [I-125] 5 had a single high affinity binding site with a K-d of 1.54 nM and a B-max of 3.40 pmol/mg protein. In vitro autoradiography demonstrated that [I-125]5 showed consistent accumulation with GlyT1 expression. The in vitro binding was greatly inhibited by GlyT1 inhibitors but not by other site ligands, which suggested the high specific binding of [I-125]5 with GlyT1. In the biodistribution and ex vivo autoradiography studies using mice, [I-125]5 showed high blood-brain barrier permeability (1.68-2.17% dose/g at 15-60 min) and similar regional brain distribution pattern with in vitro results. In addition, pre-treatment of GlyT1 ligands resulted in significant decrease of [I-125]5 binding in the GlyT1-rich regions. This preliminary study demonstrated that radio-iodinated 5 is a promising SPECT imaging probe for GlyT1. (C) 2011 Elsevier Ltd. All rights reserved.