piperidines and propargylamine

Topics: Computer Simulation; Humans; Indoles; Metabolism; Models, Chemical; Pargyline; Piperidines; Propylamines

Protecting group-free synthesis of 1,2:5,6-di-anhydro-D-mannitol, followed by ring opening with propargylamine and subsequent ring closure produced a separable mix of piperidine N-propargyl 1,5-dideoxy-1,5-imino-D-gulitol and azepane N-propargyl 1,6-dideoxy-1,6-imino-D-mannitol. In O-acetylated form, these two building blocks were subjected to CuAAC click chemistry with a panel of three differently azide-substituted glucose building blocks, producing iminosugar pseudo-disaccharides in good yield. The overall panel of eight compounds, plus 1-deoxynojirimycin (DNJ) as a benchmark, was evaluated as prospective inhibitors of almond β-glucosidase, yeast α-glucosidase and barley β-amylase. The iminosugar pseudo-disaccharides showed no inhibitory activity against almond β-glucosidase, while the parent N-propargyl 1,5-dideoxy-1,5-imino-D-gulitol and N-propargyl 1,6-dideoxy-1,6-imino-D-mannitol likewise proved to be inactive against yeast α-glucosidase. Inhibitory activity could be reinstated in the former series by appropriate substitution on nitrogen. The greater activity of the piperidine could be rationalized based on docking studies. Further, potent inhibition of β-amylase was observed with compounds from both the piperidine and azepane series.

Topics: 1-Deoxynojirimycin; alpha-Glucosidases; Azides; beta-Amylase; beta-Glucosidase; Click Chemistry; Disaccharides; Enzyme Inhibitors; Glucose; Heterocyclic Compounds, 1-Ring; Hordeum; Imino Sugars; Mannitol; Pargyline; Piperidines; Propylamines; Prunus dulcis; Saccharomyces cerevisiae; Triazoles

Topics: Alzheimer Disease; Animals; Catalase; Cholinesterase Inhibitors; Humans; Indoles; Pargyline; Piperidines; Propylamines; Signal Transduction; Superoxide Dismutase-1; Up-Regulation

The synthesis, biochemical evaluation, ADMET, toxicity and molecular modeling of novel multi-target-directed Donepezil + Propargylamine + 8-Hydroxyquinoline (DPH) hybrids 1-7 for the potential prevention and treatment of Alzheimer's disease is described. The most interesting derivative was racemic α-aminotrile4-(1-benzylpiperidin-4-yl)-2-(((8-hydroxyquinolin-5-yl)methyl)(prop-2-yn-1-yl)amino) butanenitrile (DPH6) [MAO A (IC50 = 6.2 ± 0.7 μM; MAO B (IC50 = 10.2 ± 0.9 μM); AChE (IC50 = 1.8 ± 0.1 μM); BuChE (IC50 = 1.6 ± 0.25 μM)], an irreversible MAO A/B inhibitor and mixed-type AChE inhibitor with metal-chelating properties. According to docking studies, both DPH6 enantiomers interact simultaneously with the catalytic and peripheral site of EeAChE through a linker of appropriate length, supporting the observed mixed-type AChE inhibition. Both enantiomers exhibited a relatively similar position of both hydroxyquinoline and benzyl moieties with the rest of the molecule easily accommodated in the relatively large cavity of MAO A. For MAO B, the quinoline system was hosted at the cavity entrance whereas for MAO A this system occupied the substrate cavity. In this disposition the quinoline moiety interacted directly with the FAD aromatic ring. Very similar binding affinity values were also observed for both enantiomers with ChE and MAO enzymes. DPH derivatives exhibited moderate to good ADMET properties and brain penetration capacity for CNS activity. DPH6 was less toxic than donepezil at high concentrations; while at low concentrations both displayed a similar cell viability profile. Finally, in a passive avoidance task, the antiamnesic effect of DPH6 was tested on mice with experimentally induced amnesia. DPH6 was capable to significantly decrease scopolamine-induced learning deficits in healthy adult mice.

Topics: Acetylcholinesterase; Alzheimer Disease; Animals; Chelating Agents; Cholinesterase Inhibitors; Donepezil; Hep G2 Cells; Humans; Hydroxyquinolines; Indans; Male; Memory; Molecular Docking Simulation; Monoamine Oxidase; Monoamine Oxidase Inhibitors; Pargyline; Piperidines; Propylamines; Rats

Propargylamines are synthesized via metal-free activation of the C-halogen bond of dihalomethanes and the C-H bond of terminal alkynes in a three-component coupling without catalyst or additional base and under mild reaction conditions. The dihalomethanes are used both as solvents as well as precursors for the methylene fragment (C1) in the final product. The scope of the reaction and the influence of various reaction variables has been investigated. A plausible reaction mechanism is proposed and the involvement of various intermediates that can be generated in situ in the process is discussed. The metal-free conditions also make this protocol environmentally benign and atom economical.

Topics: Alkynes; Butylamines; Green Chemistry Technology; Methylene Chloride; Molecular Structure; Pargyline; Piperidines; Propylamines; Pyrrolidines

The reaction of benzyl-protected propargyl amines and 1,1-cyclopropane diesters in the presence of catalytic Zn(NTf(2))(2) allows access to highly functionalized piperidines in excellent yields. The process proceeds via a tandem cyclopropane ring-opening/Conia-ene cyclization.

Topics: Catalysis; Combinatorial Chemistry Techniques; Cyclization; Cyclopropanes; Molecular Structure; Pargyline; Piperidines; Propylamines; Zinc