Convolamine, a tropane alkaloid extracted from Convolvulus plauricalis, is a potent sigma-1 receptor-positive modulator with cognitive and neuroprotective properties.

Background And Aim: By using an in vivo phenotypic screening assay in zebrafish, we identified Convolamine, a tropane alkaloid from Convulvus plauricalis, as a positive modulator of the sigma-1 receptor (S1R). The wfs1ab zebrafish larva, a model of Wolfram syndrome, exhibits an increased visual-motor response due to a mutation in Wolframin, a protein involved in endoplasmic reticulum-mitochondria communication. We previously reported that ligand activating S1R, restored the cellular and behavioral deficits in patient fibroblasts and zebrafish and mouse models.

Coumarin Derivatives Exert Anti-Lung Cancer Activity by Inhibition of Epithelial-Mesenchymal Transition and Migration in A549 Cells.

A series of coumarin derivatives and isosteres were synthesized from the reaction of triflic intermediates with phenylboronic acids, terminal alkynes, and organozinc compounds through -catalyzed cross-coupling reactions. The in vitro cytotoxic effect of the compounds was evaluated against two non-small cell lung carcinoma (NSCLC) cell lines (A-549 and H2170) and a normal cell line (NIH-3T3) using cisplatin as a reference drug. Additionally, the effects of the most promising coumarin derivative () in reversing the epithelial-to-mesenchymal transition (EMT) in IL-1β-stimulated A549 cells and in inhibiting the EMT-associated migratory ability in A549 cells were also evaluated.

Antiallodynic action of phosphodiesterase inhibitors in a mouse model of peripheral nerve injury.

Neuropathic pain arises as a consequence of a lesion or disease affecting the somatosensory nervous system. It is accompanied by neuronal and non-neuronal alterations, including alterations in intracellular second messenger pathways. Cellular levels of 3',5'-cyclic adenosine monophosphate (cAMP) and 3',5'-cyclic guanosine monophosphate (cGMP) are regulated by phosphodiesterase (PDE) enzymes.

Synthesis, Antileishmanial Activity and Studies of Aminoguanidine Hydrazones (AGH) and Thiosemicarbazones (TSC) Against Amastigotes.

Background: Leishmaniasis is a worldwide health problem, highly endemic in developing countries. Among the four main clinical forms of the disease, visceral leishmaniasis is the most severe, fatal in 95% of cases. The undesired side-effects from first-line chemotherapy and the reported drug resistance search for effective drugs that can replace or supplement those currently used in an urgent need.

Design, Synthesis and Biological Evaluation of Arylpyridin-2-yl Guanidine Derivatives and Cyclic Mimetics as Novel MSK1 Inhibitors. An Application in an Asthma Model.

Mitogen- and Stress-Activated Kinase 1 (MSK1) is a nuclear kinase, taking part in the activation pathway of the pro-inflammatory transcription factor NF-kB and is demonstrating a therapeutic target potential in inflammatory diseases such as asthma, psoriasis and atherosclerosis. To date, few MSK1 inhibitors were reported. In order to identify new MSK1 inhibitors, a screening of a library of low molecular weight compounds was performed, and the results highlighted the 6-phenylpyridin-2-yl guanidine (compound , IC~18 µM) as a starting hit for structure-activity relationship study.

Indole-3-guanylhydrazone hydrochloride mitigates long-term cognitive impairment in a neonatal sepsis model with involvement of MAPK and NFκB pathways.

Background: Neonatal sepsis is defined as a systemic inflammatory response caused by a suspected or proven infection, occurring in the first month of life, and remains one of the main causes of morbidity and mortality in newborn and preterm infants. Frequently, survivors of neonatal sepsis have serious long-term cognitive impairment and adverse neurologic outcomes. There is currently no specific drug treatment for sepsis.

TSPO Ligands Boost Mitochondrial Function and Pregnenolone Synthesis.

Translocator protein 18 kDa (TSPO) is located in the mitochondrial outer membrane and plays an important role in steroidogenesis and cell survival. In the central nervous system (CNS), its expression is upregulated in neuropathologies such as Alzheimer's disease (AD). Previously, we demonstrated that two new TSPO ligands based on an imidazoquinazolinone termed 2a and 2b, stimulated pregnenolone synthesis and ATP production in vitro.

Design and synthesis of 3-aminophthalazine derivatives and structural analogues as PDE5 inhibitors: anti-allodynic effect against neuropathic pain in a mouse model.

Neuropathic pain is a chronic pain caused by a lesion or disease affecting the somatosensory nervous system. To date, no specific treatment has been developed to cure this pain. Antidepressants and anticonvulsant drugs are used, but they do not demonstrate universal efficacy, and they often cause detrimental adverse effects.

Aminoguanidine Hydrazone Derivatives as Nonpeptide NPFF1 Receptor Antagonists Reverse Opioid Induced Hyperalgesia.

Neuropeptide FF receptors (NPFF1R and NPFF2R) and their endogenous ligand neuropeptide FF have been shown previously to display antiopioid properties and to play a critical role in the adverse effects associated with chronic administrations of opiates including the development of opioid-induced hyperalgesia and analgesic tolerance. In this work, we sought to identify novel NPFF receptors ligands by focusing our interest in a series of heterocycles as rigidified nonpeptide NPFF receptor ligands, starting from already described aminoguanidine hydrazones (AGHs). Binding experiments and functional assays highlighted AGH 1n and its rigidified analogue 2-amino-dihydropyrimidine 22e for in vivo experiments.

Evidence for the involvement of TNF-α, IL-1β and IL-10 in the antinociceptive and anti-inflammatory effects of indole-3-guanylhydrazone hydrochloride, an aromatic aminoguanidine, in rodents.

Background: Indole-3-guanylhydrazone hydrochloride (LQM01) is a new derivative of aminoguanidine hydrochloride, an aromatic aminoguanidine.

Methods: Mice were treated with LQM01 (5, 10, 25 or 50 mg/kg, i.p.

Phenylpyridine-2-ylguanidines and rigid mimetics as novel inhibitors of TNFα overproduction: Beneficial action in models of neuropathic pain and of acute lung inflammation.

4-phenylpyridin-2-yl-guanidine (5b): a new inhibitor of the overproduction of pro-inflammatory cytokines (TNFα and Il1β) was identified from a high-throughput screening of a chemical library on human peripheral blood mononuclear cells (PBMCs) after LPS stimulation. Derivatives, homologues and rigid mimetics of 5b were designed and synthesized, and their cytotoxicity and ability to inhibit TNFα overproduction were evaluated. Among them, compound 5b and its mimetic 12 (2-aminodihydroquinazoline) showed similar inhibitory activities, and were evaluated in vivo in models of lung inflammation and neuropathic pain in mice.

Efficient and Mild Ullmann-Type N-Arylation of Amides, Carbamates, and Azoles in Water.

A simple, sustainable, efficient, mild, and low-cost protocol was developed for d-glucose-assisted Cu-catalyzed Ullmann reactions in water for amides, carbamates, and nitrogen-containing heterocycles. The reaction was compatible with diverse aryl/heteroaryl iodides, giving highly substituted pyridine, indole, or indazole rings. This method offers an attractive alternative to existing protocols, because the reaction proceeds in aqueous media, occurs at or near ambient temperature, and provides the N-arylated products in good to high yields.

d-Glucose: An Efficient Reducing Agent for a Copper(II)-Mediated Arylation of Primary Amines in Water.

A copper-catalyzed Ullmann-type amination with primary amines in water with a combination of copper(II) triflate [Cu(OTf) ], dipivaloylmethane, and d-glucose is reported. The mild conditions and the use of an inexpensive catalyst as well as a renewable feedstock (d-glucose and the surfactant TPGS-750-M, which is derived from vitamin E) make this protocol a safe and convenient strategy for efficient C-N bond formation. This easy-to-handle procedure is extremely competitive compared to palladium-based reactions and may be used to synthesize N-containing molecules, such as drugs or organic light-emitting diodes (OLEDs).

Development of Dipeptidic hGPR54 Agonists.

A series of dipeptides were designed as potential agonists of the human KiSS1-derived peptide receptor (hGPR54). While the sequence Arg-Trp-NH was the most efficient in terms of affinity, we established a convergent synthetic strategy to optimize the N terminus. Using two successive Sonogashira cross-coupling reactions on a solid-supported peptide, we were able to introduce various alkynes at the N terminus to afford compounds with sub-micromolar affinities for hGPR54.

Functionalization of 2H-1,2,3-Triazole C-Nucleoside Template via N(2) Selective Arylation.

C-Nucleosides are an underexplored and important class of nucleosides with antiviral and anticancer activity. In addition, triazole heterocycles are well employed as a strategy to modify nucleobase in nucleoside analogues, although rare examples were described for triazoyl C-nucleosides. N(2)-Aryl-1,2,3-triazole C-nucleoside compounds that could be obtained by selective 1,2,3-triazole heterocycle N(2) arylation in 1-β-d-ribofuranosyl-2H-1,2,3-triazole substrate were designed in this study.

Effects of systematic N-terminus deletions and benzoylations of endogenous RF-amide peptides on NPFF1R, NPFF2R, GPR10, GPR54 and GPR103.

Mammalian RF-amide peptides including RF-amide-related peptides-1 and -3, neuropeptides AF and FF, Prolactin releasing peptides, Kisspeptins and RFa peptides are currently considered endogenous peptides for the GPCRs NPFF1R, NPFF2R, GPR10, GPR54 and GPR103, respectively. While NPFF1R and NPFF2R displayed high affinity for all the RF-amide peptides, GPR10, GPR54 and GPR103 only bind their cognate ligands. Through a systematic and sequential N-terminus deletion and benzoylation of either RF-amide neuropeptide (RFRP-3, NPFF, Kp-10, PrRP20, and 26RFa), we report the corresponding impact on affinity and activity towards all the RF-amide receptors (NPFF1R, NPFF2R, GPR10, GPR54 and GPR103).

Design and validation of a homogeneous time-resolved fluorescence cell-based assay targeting the ligand-gated ion channel 5-HT3A.

Ligand-gated ion channels (LGICs) are considered as attractive protein targets in the search for new therapeutic agents. Nowadays, this strategy involves the capability to screen large chemical libraries. We present a new Tag-lite ligand binding assay targeting LGICs on living cells.

Neuropeptide FF receptors as novel targets for limbic seizure attenuation.

Neuropeptide Y (NPY) is a well established anticonvulsant and first-in-class antiepileptic neuropeptide. In this study, the controversial role of NPY1 receptors in epilepsy was reassessed by testing two highly selective NPY1 receptor ligands and a mixed NPY1/NPFF receptor antagonist BIBP3226 in a rat model for limbic seizures. While BIBP3226 significantly attenuated the pilocarpine-induced seizures, neither of the highly selective NPY1 receptor ligands altered the seizure severity.

Neuropeptide FF and prolactin-releasing peptide decrease cortical excitability through activation of NPFF receptors.

Objective: Drugs with a novel mechanism of action are needed to reduce the number of people with epilepsy that are refractory to treatment. Increasing attention is paid to neuropeptide systems and several anticonvulsant neuropeptides have already been described, such as galanin, ghrelin, and neuropeptide Y (NPY). Many others, however, have not been investigated for their ability to affect epileptic seizures.

Development of a peptidomimetic antagonist of neuropeptide FF receptors for the prevention of opioid-induced hyperalgesia.

Through the development of a new class of unnatural ornithine derivatives as bioisosteres of arginine, we have designed an orally active peptidomimetic antagonist of neuropeptide FF receptors (NPFFR). Systemic low-dose administration of this compound to rats blocked opioid-induced hyperalgesia, without any apparent side-effects. Interestingly, we also observed that this compound potentiated opioid-induced analgesia.

Access to 4-alkylaminopyridazine derivatives via nitrogen-assisted regioselective Pd-catalyzed reactions.

3-Substituted, 6-substituted, and unsymmetrical 3,6-disubstituted 4-alkylaminopyridazines were prepared from a sequence of three chemo- and regioselective reactions combining amination and palladium-catalyzed cross-coupling reactions, such as reductive dehalogenation and Suzuki-Miyaura reactions. Extension of the methodology to Sonogashira reaction yielded a novel class of 3-substituted pyrrolopyridazines.

Structure-activity relationship study around guanabenz identifies two derivatives retaining antiprion activity but having lost α2-adrenergic receptor agonistic activity.

Guanabenz (GA) is an orally active α2-adrenergic agonist that has been used for many years for the treatment of hypertension. We recently described that GA is also active against both yeast and mammalian prions in an α2-adrenergic receptor-independent manner. These data suggest that this side-activity of GA could be explored for the treatment of prion-based diseases and other amyloid-based disorders.

Fully regiocontrolled polyarylation of pyridine.

Starting from commercially available 2-chloro-3-hydroxypyridine, a new route leading to the first protypical pentaarylpyridine bearing five different substituents is reported. This strategy involves a set of five sequential but fully regiocontrolled Suzuki-Miyaura reactions and highlights the 2-OBn pyridine protecting group as a key intermediate. The 2-OBn group played a double role: (i) it allowed additional bromination at position 5 and (ii) it could afford the reactive OTf species for the last C-arylation step at the less hindered 2 position of the tetraarylpyridine.

Nucleophilic substitution of azide acting as a pseudo leaving group: one-step synthesis of various aza heterocycles.

The reaction of 3-azidopropanoic acid with the carbodiimide-based coupling reagent DIC leads to a six-membered-ring intermediate acting as a versatile precursor to a diverse set of aza heterocycles, including mono-, bi-, and tricyclic compounds.