- New κ-Receptor Agonists Based upon a 2-piperidine Nucleus
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The syntheses of some 1--2-piperidines and their activities as κ-opioid receptor agonists are described.Selected structural modifications are made to the basic moiety and at the 2-, 3-, 4-, 5-, and 6-positions on the piperidine nucleus to enable structure-activity relationships to be delineated.As a result, some highly potent and selective κ-receptor agonists have been identified.In particular, this has been achieved by introduction of oxygen-containing functionality into the 4-position of the piperidine nucleus or the 3-position of the pyrrolidinylmethyl side chain.Thus, 1--2-piperidine (10) possesses high activity in the rabbit vas deferens (LVD, κ-specific tissue) (IC50 = 0.20 nM) and is a potent antinociceptive agent, as determined by the mouse acetylcholine-induced abdominal constriction test (MAC) (ED50 = 0.06 mg/kg, sc).The spirocyclic analogue 8--7-(1-pyrrolidinylmethyl)-1,4-dioxa-8-azaspirodecane (39) showed exceptionally potent activity: LVD, IC50 = 0.10 nM; MAC, ED50 = 0.001 mg/kg, sc.Both 10 and 39 displayed high selectivity for κ-opioid receptors over both μ- and δ-opioid receptor subtypes.
- Scopes, David I. C.,Hayes, Norman F.,Bays, David E.,Belton, David,Brain, John,et al.
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p. 490 - 501
(2007/10/02)
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- (2S)-1-(arylacetyl)-2-(aminomethyl)piperidine derivatives: Novel, highly selective κ opioid analgesics
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This paper describes the synthesis and structure-activity relationships as κ opioid analgesics of a novel class of 1-(arylacetyl)-2-(aminomethyl)piperidine derivatives (8). The active conformation of the pharmacophore, with a torsional angle (N1C2C7N8) of 60°, was defined with computational studies and 1H NMR. A quantitative structure-activity relationship study of the arylacetic moiety substitution indicated that the presence of an electron-withdrawing and lipophilic substituent in para and/or meta positions is required for good analgesic activity and κ affinity. The lead compounds (2S)-1-[(3,4-dichlorophenyl)acetyl]-2-(pyrrolidin-1-ylmethyl) piperidine hydrochloride (14) and (2S)-1-[[4-(trifluoromethyl)phenyl]acetyl]-2-(pyrrolidin-1- ylmethyl)piperidine hydrochloride (21) are the most κ/μ selective (respectively 6500:1 and 4100:1) and among the most potent (K(i) κ 0.24 and 0.57 nM, respectively) κ ligands identified so far. In the mouse tail flick model of antinociception, compound 14 (ED50 = 0.05 mg/kg sc) was 25 times more potent than morphine and 16 times more potent than the standard κ ligand U-50488.
- Vecchietti,Giordani,Giardina,Colle,Clarke
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p. 397 - 403
(2007/10/02)
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