Design and Synthesis of Potential Multi-Target Antidepressants: Exploration of 1-(4-(7-Azaindole)-3,6-dihydropyridin-1-yl)alkyl-3-(1-indol-3-yl)pyrrolidine-2,5-dione Derivatives with Affinity for the Serotonin Transporter.

We describe the design, synthesis and structure-activity relationship of a novel series of 1-(4-(7-azaindole)-3,6-dihydropyridin-1-yl)alkyl-3-(1-indol-3-yl)pyrrolidine-2,5-dione derivatives with combined effects on the serotonin (5-HT) and dopamine (D) receptors and the serotonin (5-HT), noradrenaline (NA), and dopamine (DA) transporters as multi-target directed ligands for the treatment of depression. All of the tested compounds demonstrated good affinity for the serotonin transporter (SERT). Among them, compounds and emerged as the lead candidates because of their promising pharmacological profile based on in vitro studies.

Contilisant+Tubastatin A Hybrids: Polyfunctionalized Indole Derivatives as New HDAC Inhibitor-Based Multitarget Small Molecules with and Activity in Neurodegenerative Diseases.

Herein, we describe the design, synthesis, and biological evaluation of 15 + hybrids. These ligands are polyfunctionalized indole derivatives developed by juxtaposing selected pharmacophoric moieties of and to act as multifunctional ligands. Compounds and were identified as potent HDAC6 inhibitors (IC = 0.

Unlocking the potential of higher-molecular-weight 5-HTR ligands: Synthesis, affinity, and ADMET examination.

An increasing number of drugs introduced to the market and numerous repositories of compounds with confirmed activity have posed the need to revalidate the state-of-the-art rules that determine the ranges of properties the compounds should possess to become future drugs. In this study, we designed a series of two chemotypes of aryl-piperazine hydantoin ligands of 5-HTR, an attractive target in search for innovative CNS drugs, with higher molecular weight (close to or over 500). Consequently, 14 new compounds were synthesised and screened for their receptor activity accompanied by extensive docking studies to evaluate the observed structure-activity/properties relationships.

Uncovering the unique characteristics of different groups of 5-HTR ligands with reference to their interaction with the target protein.

Background: The serotonin 5-HT receptor has attracted much more research attention, due to the therapeutic potential of its ligands being increasingly recognized, and the possibilities that lie ahead of these findings. There is a growing body of evidence indicating that these ligands have procognitive, pro-social, and anti-depressant properties, which offers new avenues for the development of treatments that could address socially important conditions related to the malfunctioning of the central nervous system. The aim of our study was to unravel the molecular determinants for 5-HTR ligands that govern their activity towards the receptor.

Unraveling psilocybin's therapeutic potential: behavioral and neuroplasticity insights in Wistar-Kyoto and Wistar male rat models of treatment-resistant depression.

Rationale: Our study aimed to unravel the unknown mechanisms behind the exceptional efficacy of Psilocybin (PSI) in treating treatment-resistant depression (TRD). Focusing on Wistar-Kyoto (WKY) rats with a TRD phenotype and Wistar (WIS) rats as a normative comparison, we investigated behavioral and neuroplasticity-related responses to PSI, striving to shed light on the distinctive features of its antidepressant effects.

Objectives: We set out to assess the behavioral impact of acute and prolonged PSI administration on WKY and WIS rats, employing Novel Object Recognition (NORT), Social Interaction (SI), and Forced Swimming Test (FST).

5-HT receptor neutral antagonists protect astrocytes: A lesson from 2-phenylpyrrole derivatives.

The serotonin type 6 receptor (5-HTR) displays a strong constitutive activity, suggesting it participates largely in the physiological and pathological processes controlled by the receptor. The active states of 5-HTR engage particular signal transduction pathways that lead to different biological responses. In this study, we present the development of 5-HTR neutral antagonists at Gs signaling built upon the 2-phenylpyrrole scaffold.

Physicochemical, structural and biological characterisation of poly(3-hydroxyoctanoate) supplemented with diclofenac acid conjugates - Harnessing the potential in the construction of materials for skin regeneration processes.

This study involved creating oligomeric conjugates of 3-hydroxy fatty acids and diclofenac, named Dic-oligo(3HAs). Advanced NMR techniques confirmed no free diclofenac in the mix. We tested diclofenac release under conditions resembling healthy and chronic wound skin.

Synthesis and biological evaluation of novel 3-(5-substituted-1H-indol-3-yl)pyrrolidine-2,5-dione derivatives with a dual affinity for serotonin 5-HT receptor and SERT.

The serotonin 1A (5-HT) receptors and serotonin transporter (SERT) are important biological targets in the treatment of diseases of the central nervous system, especially for depression. In this study, new 3-(1H-indol-3-yl)pyrrolidine-2,5-dione derivatives linked with the 3-(1,2,3,6-tetrahydropyridin-4-yl)-1H-indole moiety were synthesised and evaluated for their affinity for 5-HT receptor and serotonin reuptake inhibition. Selected compounds were then tested for their affinity for D, 5-HT, 5-HT and 5-HT receptors, and also in in vitro metabolic stability assays in human microsomes.

Superiority of the Triple-Acting 5-HTR/5-HTR Antagonist and MAO-B Reversible Inhibitor over 5-HTR Antagonist Intepirdine in Alleviation of Cognitive Deficits in Rats.

The multifactorial origin and neurochemistry of Alzheimer's disease (AD) call for the development of multitarget treatment strategies. We report a first-in-class triple acting compound that targets serotonin type 6 and 3 receptors (5-HT-Rs) and monoamine oxidase type B (MAO-B) as an approach for treating AD. The key structural features required for MAO-B inhibition and 5-HTR antagonism and interaction with 5-HTR were determined using molecular dynamic simulations and cryo-electron microscopy, respectively.

Repeated low doses of psilocybin increase resilience to stress, lower compulsive actions, and strengthen cortical connections to the paraventricular thalamic nucleus in rats.

Psilocybin (a classic serotonergic psychedelic drug) has received appraisal for use in psychedelic-assisted therapy of several psychiatric disorders. A less explored topic concerns the use of repeated low doses of psychedelics, at a dose that is well below the psychedelic dose used in psychedelic-assisted therapy and often referred to as microdosing. Psilocybin microdose users frequently report increases in mental health, yet such reports are often highly biased and vulnerable to placebo effects.

Novel object recognition test as an alternative approach to assessing the pharmacological profile of sigma-1 receptor ligands.

Background: Although the terms "agonist" and "antagonist" have been used to classify sigma-1 receptor (σR) ligands, an unambiguous definition of the functional activity is often hard. In order to determine the pharmacological profile of σR ligands, the most common method is to assess their potency to alleviate opioid analgesia. It has been well established that σR agonists reduce opioid analgesic activity, while σR antagonists have been demonstrated to enhance opioid analgesia in different pain models.

Dual Piperidine-Based Histamine H and Sigma-1 Receptor Ligands in the Treatment of Nociceptive and Neuropathic Pain.

In search of new dual-acting histamine H/sigma-1 receptor ligands, we designed a series of compounds structurally based on highly active ligands previously studied and described by our team. However, we kept in mind that within the previous series, a pair of closely related compounds, and , differing only in the piperazine/piperidine moiety in the structural core showed a significantly different affinity at sigma-1 receptors (σRs). Therefore, we first focused on an in-depth analysis of the protonation states of piperazine and piperidine derivatives in the studied compounds.

Amisulpride as a potential disease-modifying drug in the treatment of tauopathies.

Introduction: Hyperphosphorylation and aggregation of the microtubule-associated protein tau cause the development of tauopathies, such as Alzheimer's disease and frontotemporal dementia (FTD). We recently uncovered a causal link between constitutive serotonin receptor 7 (5-HT7R) activity and pathological tau aggregation. Here, we evaluated 5-HT7R inverse agonists as novel drugs in the treatment of tauopathies.

Structure-Activity Relationships and Therapeutic Potential of Purinergic P2X7 Receptor Antagonists.

The purinergic P2X7 receptor (P2X7R), an ATP-gated non-selective cation channel, has emerged as a gatekeeper of inflammation that controls the release of proinflammatory cytokines. As a key player in initiating the inflammatory signaling cascade, the P2X7 receptor is currently under intense scrutiny as a target for the treatment of different pathologies, including chronic inflammatory disorders (rheumatoid arthritis and osteoarthritis), chronic neuropathic pain, mood disorders (depression and anxiety), neurodegenerative diseases, ischemia, cancer (leukemia), and many others. For these reasons, pharmaceutical companies have invested in discovering compounds able to modulate the P2X7R and filed many patent applications.

Gα-derived peptide binds the µ-opioid receptor.

Background: G protein-coupled receptors (GPCRs) transduce external stimuli into the cell by G proteins via an allosteric mechanism. Agonist binding to the receptor stimulates GDP/GTP exchange within the heterotrimeric G protein complex, whereas recent structures of GPCR-G protein complexes revealed that the H5, S1 and S2 domains of Gα are involved in binding the active receptor, earlier studies showed that a short peptide analog derived from the C-terminus (H5) of the G protein transducin (G) is sufficient to stabilize rhodopsin in an active form.

Methods: We have used Molecular Dynamics simulations along with biological evaluation by means of radio-ligand binding assay to study the interactions between Gα-derived peptide (G-peptide) and the µ-opioid receptor (µOR).

Impact of the Substitution Pattern at the Basic Center and Geometry of the Amine Fragment on 5-HT and DR Affinity in the 1-Pyrrolo[3,2-]quinoline Series.

Salt bridge (SB, double-charge-assisted hydrogen bonds) formation is one of the strongest molecular non-covalent interactions in biological systems, including ligand-receptor complexes. In the case of G-protein-coupled receptors, such an interaction is formed by the conserved aspartic acid (D3.32) residue and the basic moiety of the aminergic ligand.

Design and Synthesis of New Quinazolin-4-one Derivatives with Negative mGlu Receptor Modulation Activity and Antipsychotic-Like Properties.

Following the glutamatergic theory of schizophrenia and based on our previous study regarding the antipsychotic-like activity of mGlu NAMs, we synthesized a new compound library containing 103 members, which were examined for NAM mGlu activity in the T-REx 293 cell line expressing a recombinant human mGlu receptor. Out of the twenty-two scaffolds examined, active compounds were found only within the quinazolinone chemotype. 2-(2-Chlorophenyl)-6-(2,3-dimethoxyphenyl)-3-methylquinazolin-4(3)-one (, , mGlu IC = 6.

Isomeric Activity Cliffs-A Case Study for Fluorine Substitution of Aminergic G Protein-Coupled Receptor Ligands.

Currently, G protein-coupled receptors (GPCRs) constitute a significant group of membrane-bound receptors representing more than 30% of therapeutic targets. Fluorine is commonly used in designing highly active biological compounds, as evidenced by the steadily increasing number of drugs by the Food and Drug Administration (FDA). Herein, we identified and analyzed 898 target-based F-containing isomeric analog sets for SAR analysis in the ChEMBL database-FSAR sets active against 33 different aminergic GPCRs comprising a total of 2163 fluorinated (1201 unique) compounds.

1-(Arylsulfonyl-isoindol-2-yl)piperazines as 5-HTR Antagonists: Mechanochemical Synthesis, In Vitro Pharmacological Properties and Glioprotective Activity.

In addition to the canonical Gs adenylyl cyclase pathway, the serotonin type 6 receptor (5-HTR) recruits additional signaling pathways that control cognitive function, brain development, and synaptic plasticity in an agonist-dependent and independent manner. Considering that aberrant constitutive and agonist-induced active states are involved in various pathological mechanisms, the development of biased ligands with different functional profiles at specific 5-HTR-elicited signaling pathways may provide a novel therapeutic perspective in the field of neurodegenerative and psychiatric diseases. Based on the structure of SB-258585, an inverse agonist at 5-HTR-operated Gs and Cdk5 signaling, we designed a series of 1-(arylsulfonyl-isoindol-2-yl)piperazine derivatives and synthesized them using a sustainable mechanochemical method.

Structure, Mutagenesis, and QM:MM Modeling of 3-Ketosteroid Δ-Dehydrogenase from ─The Role of a New Putative Membrane-Associated Domain and Proton-Relay System in Catalysis.

3-Ketosteroid Δ-dehydrogenases (KstD) are important microbial flavin enzymes that initiate the metabolism of steroid ring A and find application in the synthesis of steroid drugs. We present a structure of the KstD from (AcmB), which contains a previously uncharacterized putative membrane-associated domain and extended proton-relay system. The experimental and theoretical studies show that the steroid Δ-dehydrogenation proceeds according to the Ping-Pong bi-bi kinetics and a two-step base-assisted elimination (E2cB) mechanism.

Serodolin, a β-arrestin-biased ligand of 5-HT receptor, attenuates pain-related behaviors.

G protein–coupled receptors (GPCRs) are involved in regulation of manifold physiological processes through coupling to heterotrimeric G proteins upon ligand stimulation. Classical therapeutically active drugs simultaneously initiate several downstream signaling pathways, whereas biased ligands, which stabilize subsets of receptor conformations, elicit more selective signaling. This concept of functional selectivity of a ligand has emerged as an interesting property for the development of new therapeutic molecules.

Mining anion-aromatic interactions in the Protein Data Bank.

Mutual positioning and non-covalent interactions in anion-aromatic motifs are crucial for functional performance of biological systems. In this context, regular, comprehensive Protein Data Bank (PDB) screening that involves various scientific points of view and individual critical analysis is of utmost importance. Analysis of anions in spheres with radii of 5 Å around all 5- and 6-membered aromatic rings allowed us to distinguish 555 259 unique anion-aromatic motifs, including 92 660 structures out of the 171 588 structural files in the PDB.

Overcoming undesirable hERG affinity by incorporating fluorine atoms: A case of MAO-B inhibitors derived from 1 H-pyrrolo-[3,2-c]quinolines.

The incorporation of the fluorine motif is a strategy widely applied in drug design for modulating the activity, physicochemical parameters, and metabolic stability of chemical compounds. In this study, we attempted to reduce the affinity for ether-à-go-go-related gene (hERG) channel by introducing fluorine atoms in a group of 1H-pyrrolo[3,2-c]quinolines that are capable of inhibiting monoamine oxidase type B (MAO-B). A series of structural modifications guided by in vitro evaluation of MAO-B inhibition and antitargeting for hERG channels were performed, which led to the identification of 1-(3-chlorobenzyl)-4-(4,4-difluoropiperidin-1-yl)-1H-pyrrolo[3,2-c]quinoline (26).

Activation of the 5-HT7 receptor and MMP-9 signaling module in the hippocampal CA1 region is necessary for the development of depressive-like behavior.

Major depressive disorder is a complex disease resulting from aberrant synaptic plasticity that may be caused by abnormal serotonergic signaling. Using a combination of behavioral, biochemical, and imaging methods, we analyze 5-HT7R/MMP-9 signaling and dendritic spine plasticity in the hippocampus in mice treated with the selective 5-HT7R agonist (LP-211) and in a model of chronic unpredictable stress (CUS)-induced depressive-like behavior. We show that acute 5-HT7R activation induces depressive-like behavior in mice in an MMP-9-dependent manner and that post mortem brain samples from human individuals with depression reveal increased MMP-9 enzymatic activity in the hippocampus.