Fighting the Influenza A virus. New scaffolds and therapeutic targets

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Dimerization of highly pyramidalized 3,4,8,9-tetramethyltetracyclo[4.4.0.03,9.04,8]dec-1(6)-ene to a hydrocarbon featuring four cyclohexane rings in boat conformation

The synthesis, chemical trapping, and dimerization of a highly pyramidalized alkene is reported. Its dimer is a unique nonacycle featuring three planar cyclobutane rings, four cyclopentane rings, and four cyclohexane rings in boat conformations. The X-ray diffraction analysis showed a H-H distance between the flagpole hydrogen atoms of 1.999 and a separation of 2.619 between the two flagpole carbon atoms. The three cyclobutane rings of the dimer were thermally stabl

Towards a Novel Class of Multitarget-Directed Ligands: Dual P2X7-NMDA Receptor Antagonists

Multi-target-directed ligands (MTDLs) offer new hope for the treatment of multifactorial complex diseases such as Alzheimer's Disease (AD). Herein, we present compounds aimed at targeting the NMDA and the P2X7 receptors, which embody a different approach to AD therapy. On one hand, we are seeking to delay neurodegeneration targeting the glutamatergic NMDA receptors; on the other hand, we also aim to reduce neuroinflammation, targeting P2X7 receptors. Although the NMDA receptor is a widely recognized therapeutic target in treating AD, the P2X7 receptor remains largely unexplored for this purpose; therefore, the dual inhibitor presented herein¿which is open to further optimization¿represents the first member of a new class of MTDLs

Escape from adamantane: scaffold optimization of novel P2X7 antagonists featuring complex polycycles

The adamantane scaffold, despite being widely used in medicinal chemistry, is not devoid of problems. In recent years we have developed new polycyclic scaffolds as surrogates of the adamantane group with encouraging results in multiple targets. As an adamantane scaffold is a common structural feature in several P2X7 receptor antagonists, herein we report the synthesis and pharmacological evaluation of multiple replacement options of adamantane that maintain a good activity profile. Molecular modeling studies support the binding of the compounds to a site close to the central pore, rather than to the ATP-binding site and shed light on the structural requirements for novel P2X7 antagonists

Azapeptide activity-based probes for the SARS-CoV-2 main protease enable visualization of inhibition in infected cells

The COVID-19 pandemic has revealed the vulnerability of the modern, global society. With expected waves of future infections by SARS-CoV-2, treatment options for infected individuals will be crucial in order to decrease mortality and hospitalizations. The SARS-CoV-2 main protease is a validated drug target, for which the first inhibitor has been approved for use in patients. To facilitate future work on this drug target, we designed a solid-phase synthesis route towards azapeptide activity-based probes that are capped with a cysteine-reactive electrophile for covalent modification of the active site of Mpro. This design led to the most potent ABP for Mpro and one of the most potent inhibitors reported thus far. We demonstrate that this ABP can be used to visualize Mpro activity and target engagement by drugs in infected cells

3D‐printed polypropylene continuous‐flow column reactors: exploration of reactor utility in SNAr reactions and the synthesis of bicyclic and tetracyclic heterocycles

3D printing has the potential to transform the way in which chemical reactions are carried out due to its low‐cost, ease‐of‐use as a technology and its capacity to expedite the development of iteratively enhanced prototypes. In this present study, we developed a novel, low‐cost polypropylene (PP) column reactor that was incorporated into an existing continuous‐flow reactor for the synthesis of heterocycles. The utility and solvent resistance of the printed devices were explored in SNAr reactions to produce substituted aniline derivatives and in the synthesis of bicyclic and tetracyclic heterocycles. Using this approach, a range of heterocyclic compounds was synthesised including the core structure of the natural product (±)‐γ‐lycorane and structurally complex compounds based on the tetracyclic core of the erythrina alkaloids

Synthesis, in Vitro Profiling, and in Vivo Evaluation of Benzohomoadamantane-Based Ureas for Visceral Pain: A New Indication for Soluble Epoxide Hydrolase Inhibitors

The soluble epoxide hydrolase (sEH) has been suggested as a pharmacological target for the treatment of several diseases, including pain-related disorders. Herein, we report further medicinal chemistry around new benzohomoadamantane-based sEH inhibitors (sEHI) in order to improve the drug metabolism and pharmacokinetics properties of a previous hit. After an extensive in vitro screening cascade, molecular modeling, and in vivo pharmacokinetics studies, two candidates were evaluated in vivo in a murine model of capsaicin-induced allodynia. The two compounds showed an anti-allodynic effect in a dose-dependent manner. Moreover, the most potent compound presented robust analgesic efficacy in the cyclophosphamide-induced murine model of cystitis, a well-established model of visceral pain. Overall, these results suggest painful bladder syndrome as a new possible indication for sEHI, opening a new range of applications for them in the visceral pain field

A novel class of multitarget anti-Alzheimer benzohomoadamantane‒chlorotacrine hybrids modulating cholinesterases and glutamate NMDA receptors

The development of multitarget compounds against multifactorial diseases, such as Alzheimer's disease, is an area of very intensive research, due to the expected superior therapeutic efficacy that should arise from the simultaneous modulation of several key targets of the complex pathological network. Here we describe the synthesis and multitarget biological profiling of a new class of compounds designed by molecular hybridization of an NMDA receptor antagonist fluorobenzohomoadamantanamine with the potent acetylcholinesterase (AChE) inhibitor 6-chlorotacrine, using two different linker lengths and linkage positions, to preserve or not the memantine-like polycyclic unsubstituted primary amine. The best hybrids exhibit greater potencies than parent compounds against AChE (IC50 0.33 nM in the best case, 44-fold increased potency over 6-chlorotacrine), butyrylcholinesterase (IC50 21 nM in the best case, 24-fold increased potency over 6-chlorotacrine), and NMDA receptors (IC50 0.89 µM in the best case, 2-fold increased potency over the parent benzohomoadamantanamine and memantine), which suggests an additive effect of both pharmacophoric moieties in the interaction with the primary targets. Moreover, most of these compounds have been predicted to be brain permeable. This set of biological properties makes them promising leads for further anti-Alzheimer drug development

New polycyclic small molecules as ion channel modulators

[cat] L’objectiu de la present tesi doctoral consisteix en desenvolupar molècules policícliques de baix pes molecular que tinguin com a diana tres canals iònics específics: la viroporina A/M2 del virus de la grip, el receptor purinèrgic dependent de lligand P2X7 i el receptor glutamatèrgic dependent de lligand N-metil-D-Aspartat, per tal de modular-los d’una manera tal que n’evitin o millorin el desenvolupament dels processos patogènics associats a aquestes proteïnes i/o que permetin ser emprades com a eines de recerca. En el capítol 1 es presenta una introducció general del paper dels canals iònics, així com una descripció més específica de cadascun dels 3 canals objecte d’estudi en aquesta Tesi. Els objectius d’aquest treball es detallen en el capítol 2, després del qual, en el capítol 3 es presenten un seguit d’anàlegs per contracció d’anell del fàrmac comercial Amantadina, resultant-ne els primers inhibidors duals del canal M2 del virus de la Influenza A descrits en la bibliografia, actius sobre la soca salvatge (wt) i sobre el mutant resistent a fàrmacs V27A (Rey-Carrizo, M. et al. J. Med. Chem. 2013, 56, 9265). Seguidament en la part A del capítol 4 es gràcies a estudis in silico, s’observa com un dels inhibidors triples presenta un mode d’unió diferent sobre els canals wt i V27A, que podria estar directament relacionat amb el mecanisme de resistència a fàrmacs del mutant V27A (Rey-Carrizo, M., et al. J. Med. Chem. 2014, 57(13), 5738). En el capítol 5 es completa el treball presentant per primera vegada la proba experimental d’una possible explicació del mecanisme de resistència a fàrmacs del mutant V27A. (Barniol-Xicota, M., et al. manuscrit acceptat al J. Med. Chem.). Com a continuació en el capítol 6 s’explora una diana diferent de la viroporina M2: l’hemaglutinina (HA) (Leiva, R., et al. manuscrit pendent d’enviar a J. Med. Chem.). El capítol 7 representa el primer treball que marca l’inici de la línia de recerca d’antagonistes del receptor P2X7 en el grup. (Barniol-Xicota, M., et al. manuscrit en revisió al Bioorg. Med. Chem. Lett.). Finalment, en el capítol 8, es presenten els primers exemples descrits a la bibliografia de multi-target directed ligands (MTDL) amb els receptors NMDA i P2X7 com a dianes. (Karou, O., et al. manuscrit pendent d’enviar a ACS Med. Chem. Lett.). Deixant de banda la recerca de compostos bioactius en la part B del capítol 4 es descriu un estudi teòric i experimental d’un alquè altament piramidalitzat, derivat de l’estructura d’un compost bioactiu detallat en la part A del mateix capítol. (Rey-Carrizo, M. et al. Angew. Chem. Int. Ed. 2014, 53, 8195)

Comparative Analysis of Maleic Acid Copolymer-Based Lipid Nanodiscs Reveals Preferential Lipid and Protein Solubilization

Membrane proteins are key in a large number of physiological and pathological processes. Their study often involves a prior detergent solubilization step, which strips away the membrane and can jeopardize membrane protein integrity. A recent alternative to detergents encompasses maleic acid based copolymers (xMAs), which disrupt the lipid bilayer and form lipid protein nanodiscs (xMALPs) soluble in aqueous buffer. Although xMALPs are often referred to as native nanodiscs, little is known about the resemblance of their lipid and protein content to the native bilayer. Here we have analyzed prokaryotic and eukaryotic xMALPs using lipidomics and in-gel analysis. Our results show that the xMALPs content varies with the chemical properties of the used xMA and that some of these nanodiscs are less native than initially thought.<br /