Synthesis of new tacrine analogues from 4-amino-1H-pyrrole-3-carbonitrile

An easy preparation of 4-aminopyrrole-3-carbonitrile derivatives, and their transformation into new substituted pyrrolo[3,2-b]pyridines is described, in one step, via Friedländer reaction under microwave irradiation and classical heating methods. The use of microwave irradiation led to high conversion and shorter times.Fundação para a Ciência e a Tecnologia (FCT) - NMR Network, REEQ/ 630/QUI/2005, SFRH/BPD/31490/2006Fundo Europeu de Desenvolvimento Regional (FEDER

N-methyl-N-((1-methyl-5-(3-(1-(2-methylbenzyl)piperidin-4-yl)propoxy)-1H-indol-2-yl)methyl)prop-2-yn-1-amine, a new cholinesterase and monoamine oxidase dual inhibitor

On the basis of N-((5-(3-(1-benzylpiperidin-4-yl)propoxy)-1-methyl-1H-indol-2-yl)methyl)-N-methylprop-2-yn-1-amine (II, ASS234) and QSAR predictions, in this work we have designed, synthesized, and evaluated a number of new indole derivatives from which we have identified N-methyl-N-((1-methyl-5-(3-(1-(2-methylbenzyl)piperidin-4-yl)propoxy)-1H-indol-2-yl)methyl)prop-2-yn-1-amine (2, MBA236) as a new cholinesterase and monoamine oxidase dual inhibitor.PostprintPostprintPeer reviewe

ASS234, as a new Multi-Target Directed propargylamine for Alzheimer’s disease therapy

MU and JMC thank MINECO (Spain) for support (Grant SAF2012-33304; SAF2015-65586-R). RRR, MU, GE and JMC thank EU (COST Action 1103) for support.The complex nature of Alzheimer’s disease (AD) has prompted the design of Multi-Target-Directed Ligands (MTDL) able to bind to diverse biochemical targets involved in the progress and development of the disease. In this context, we have designed a number of MTD propargylamines showing antioxidant, anti-betaamyloid, anti-inflammatory, as well as cholinesterase and monoamine oxidase inhibition capacities. Here, we describe these properties in the MTDL ASS234, our lead-compound ready to enter in pre-clinical studies for AD, as a new multipotent, permeable cholinesterase/monoamine oxidase inhibitor, able to inhibit Aβ- aggregation, possessing antioxidant and neuroprotective properties.Publisher PDFPeer reviewe

Evidence for a cyanine link between propargylamine drugs and monoamine oxidase clarifies the inactivation mechanism

The authors acknowledge the financial support from the Slovenian Research Agency (research core funding No. P1-0005 and P1-0012). We thank COST CA15135 for facilitating collaboration on multi-target compounds and providing support for publication. Part of this work was also supported by the bilateral cooperation between the Royal Society of Edinburgh and the Slovenian Academy of Sciences and Arts and by COST Action CM1103 which facilitated short research visits in Ljubljana and St Andrews, respectively.Successful propargylamine drugs such as deprenyl inactivate monoamine oxidase (MAO), a target in multi-faceted approaches to prevent neurodegeneration in the aging population, but the chemical structure and mechanism of the irreversible inhibition are still debated. We characterized the covalent cyanine structure linking the multi-target propargylamine inhibitor ASS234 and the flavin adenine dinucleotide in MAO-A using a combination of ultra-high performance liquid chromatography, spectroscopy, mass spectrometry, and computational methods. The partial double bond character of the cyanine chain gives rise to 4 interconverting geometric isomers of the adduct which were chromatographically separated at low temperatures. The configuration of the cyanine linker governs adduct stability with segments of much higher flexibility and rigidity than previously hypothesized. The findings indicate the importance of intramolecular electrostatic interactions in the MAO binding site and provide key information relevant to incorporation of the propargyl moiety into novel multi-target drugs. Based on the structure, we propose a mechanism of MAO inactivation applicable to all propargylamine inhibitors.Publisher PDFPeer reviewe

Donepezil-like multifunctional agents: Design, synthesis, molecular modeling and biological evaluation

Currently available drugs against Alzheimer's disease (AD) are only able to ameliorate the disease symptoms resulting in a moderate improvement in memory and cognitive function without any efficacy in preventing and inhibiting the progression of the pathology. In an effort to obtain disease-modifying anti-Alzheimer's drugs (DMAADs) following the multifactorial nature of AD, we have recently developed multifunctional compounds. We herein describe the design, synthesis, molecular modeling and biological evaluation of a new series of donepezil-related compounds possessing metal chelating properties, and being capable of targeting different enzymatic systems related to AD (cholinesterases, ChEs, and monoamine oxidase A, MAO-A). Among this set of analogues compound 5f showed excellent ChEs inhibition potency and a selective MAO-A inhibition (vs MAO-B) coupled to strong complexing properties for zinc and copper ions, both known to be involved in the progression of AD. Moreover, 5f exhibited moderate antioxidant properties as found by in vitro assessment. This compound represents a novel donepezil–hydroxyquinoline hybrid with DMAAD profile paving the way to the development of a novel class of drugs potentially able to treat AD

Quinoxalinetacrine QT78, a cholinesterase inhibitor as a potential ligand for Alzheimer’s disease therapy

We report the synthesis and relevant pharmacological properties of the quinoxalinetacrine (QT) hybrid QT78 in a project targeted to identify new non-hepatotoxic tacrine derivatives for Alzheimer\u2019s disease therapy. We have found that QT78 is less toxic than tacrine at high concentrations (from 100 \ub5M to 1 mM), less potent than tacrine as a ChE inhibitor, but shows selective BuChE inhibition (IC50 (hAChE) = 22.0 \ub1 1.3 \ub5M; IC50 (hBuChE) = 6.79 \ub1 0.33 \ub5M). Moreover, QT78 showed effective and strong neuroprotection against diverse toxic stimuli, such as rotenone plus oligomycin-A or okadaic acid, of biological significance for Alzheimer\u2019s disease

N-benzylpiperidine derivatives as α7 nicotinic receptor antagonists

This document is the accepted manuscript version of a Published Work that appeared in final form in ACS Chemical Neuroscience 7.8, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see DOI: 10.1021/acschemneuro.6b00122.A series of multitarget directed propargylamines, as well as other differently susbstituted piperidines have been screened as potential modulators of neuronal nicotinic acetylcholine receptors (nAChRs). Most of them showed antagonist actions on α7 nAChRs. Especially, compounds 13, 26, and 38 displayed submicromolar IC50 values on homomeric α7 nAChRs, whereas they were less effective on heteromeric α3β4 and α4β2 nAChRs (up to 20-fold higher IC50 values in the case of 13). Antagonism was concentration dependent and noncompetitive, suggesting that these compounds behave as negative allosteric modulators of nAChRs. Upon the study of a series of less complex derivatives, the N-benzylpiperidine motif, common to these compounds, was found to be the main pharmacophoric group. Thus, 2-(1-benzylpiperidin-4-yl)-ethylamine (48) showed an inhibitory potency comparable to the one of the previous compounds and also a clear preference for α7 nAChRs. In a neuroblastoma cell line, representative compounds 13 and 48 also inhibited, in a concentration-dependent manner, cytosolic Ca2+ signals mediated by nAChRs. Finally, compounds 38 and 13 inhibited 5-HT3A serotonin receptors whereas they had no effect on α1 glycine receptors. Given the multifactorial nature of many pathologies in which nAChRs are involved, these piperidine antagonists could have a therapeutic potential in cases where cholinergic activity has to be negatively modulated.This work was supported by grants SAF2011-22802 to S.S., SAF2012-33304 to J.M.-C., CSD2008-00005 (the Spanish Ion Channel Initiative-CONSOLIDER INGENIO 2010) to M.C. from the Spanish Ministry of Science and Innovation (Ministerio de Economía y Competitividad)

Design and Synthesis of Multi-Functional Ligands through Hantzsch Reaction: Targeting Ca2+ Channels, Activating Nrf2 and Possessing Cathepsin S Inhibitory, and Antioxidant Properties

This work relates to the design and synthesis of a series of novel multi-target directed ligands (MTDLs), i.e., compounds 4a–l, via a convenient one-pot three-component Hantzsch reaction. This approach targeted calcium channel antagonism, antioxidant capacity, cathepsin S inhibition, and interference with Nrf2 transcriptional activation. Of these MTDLs, 4i emerged as a promising compound, demonstrating robust antioxidant activity, the ability to activate Nrf2-ARE pathways, as well as calcium channel blockade and cathepsin S inhibition. Dihydropyridine 4i represents the first example of an MTDL that combines these biological activities.This work was supported by the Regional Council of Franche-Comté (2022Y-13659 and 13660 ACCURATE PROJECT).Peer reviewe

Exploring the Potential of Sulfonamide-Dihydropyridine Hybrids as Multitargeted Ligands for Alzheimer’s Disease Treatment

Alzheimer’s disease (AD) is a multifactorial neurodegenerative disease that has a heavy social and economic impact on all societies and for which there is still no cure. Multitarget-directed ligands (MTDLs) seem to be a promising therapeutic strategy for finding an effective treatment for this disease. For this purpose, new MTDLs were designed and synthesized in three steps by simple and cost-efficient procedures targeting calcium channel blockade, cholinesterase inhibition, and antioxidant activity. The biological and physicochemical results collected in this study allowed us the identification two sulfonamide-dihydropyridine hybrids showing simultaneous cholinesterase inhibition, calcium channel blockade, antioxidant capacity and Nrf2-ARE activating effect, that deserve to be further investigated for AD therapy.This work was supported by the Regional Council of Franche-Comté (2022Y-13659 and 13660 Accurate Project).Peer reviewe

Preclinical Characterization of Antioxidant Quinolyl Nitrone QN23 as a New Candidate for the Treatment of Ischemic Stroke

Nitrones are encouraging drug candidates for the treatment of oxidative stress-driven diseases such as acute ischemic stroke (AIS). In a previous study, we found a promising quinolylnitrone, QN23, which exerted a neuroprotective effect in neuronal cell cultures subjected to oxygen–glucose deprivation and in experimental models of cerebral ischemia. In this paper, we update the biological and pharmacological characterization of QN23. We describe the suitability of intravenous administration of QN23 to induce neuroprotection in transitory four-vessel occlusion (4VO) and middle cerebral artery occlusion (tMCAO) experimental models of brain ischemia by assessing neuronal death, apoptosis induction, and infarct area, as well as neurofunctional outcomes. QN23 significantly decreased the neuronal death and apoptosis induced by the ischemic episode in a dose-dependent manner and showed a therapeutic effect when administered up to 3 h after post-ischemic reperfusion onset, effects that remained 11 weeks after the ischemic episode. In addition, QN23 significantly reduced infarct volume, thus recovering the motor function in a tMCAO model. Remarkably, we assessed the antioxidant activity of QN23 in vivo using dihydroethidium as a molecular probe for radical species. Finally, we describe QN23 pharmacokinetic parameters. All these results pointing to QN23 as an interesting and promising preclinical candidate for the treatment of AIS.This work was supported by the Instituto de Salud Carlos III and co-financed by the European Development Regional Fund (FEDER) through grants PI18/00255, RD16/0019/0006, and RD21/0006/0019 to J.M. and A.A., and RD16/0019/0008 and RD21/0006/0014 to J.B.S.; the MINECO grant SAF2015-65586-R to J.M.-C.; and the Comunidad de Madrid Neurocentro project B2017/BMD-3760 to D.G.-N