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We designed the synthesis of a small library of 3-substituted-3,6-diazabicyclo[3.1.1]heptanes whose affinity on neuronal nicotinic receptors (nAChRs) was evaluated. Among the synthesized compounds, the 5-(3,6-diazabicyclo[3.1.1]heptane-3-yl)-N-(2-fluorophenyl)nicotinamide 43 proved to be the most interesting compound with α4β2Ki value of 10 pM and a very high α7/α4β2 selectivity. Furthermore, compounds 35, 39 and 43 elicited a selective partial agonist activity for α4β2 nAChR subtype. Finally, in this paper we also report the conclusions on the 3,6-diazabicyclo[3.1.1]heptanes as ligands for nAChRs, resulting from our consolidated structure activity relationship (SAR) studies on this template.

The cholinergic pathways in the central nervous system (CNS) of animals and humans are important for cognitive and behavioural functions. Until a few years ago, it was thought that the key molecules transducing the cholinergic message were the metabotropic muscarinic receptors, but it is now known that ionotropic neuronal nicotinic receptors (nAChRs) are also involved. Based on recent studies, we prepared a small library of novel 3-substituted-3,6-diazabicyclo [3.1.1]heptanes, whose binding activity and functionality have been assayed. Among the synthesized compounds, the 3-(anilino)pyridine series resulted in the most interesting compounds with α4β2 Ki values ranging from 0.0225 nM (12g) to 2.06 nM (12o).

There is a growing evidence of the relation between an excessive release of pro-inflammatory IL-1beta triggered by the inflammasome-caspase 1 complex, and various immune and inflammatory disorders, including CNS diseases such as Alzheimer's (AD), Parkinson's (PD) and Huntington's (HD) diseases, amyotrophic lateral sclerosis (ALS), and multiple sclerosis (MS). Moreover, there is also a growing evidence that the pathway inflammasome NLRP3/caspase-1 is overactivated by the SARS-Cov-2 and may be responsible for the high mortality observed in the COVID-19 patients due to the inflammatory internal organs collapse driven by the cytokine storm induced by the virus. It is now quite clear that an effective pharmacological approach to Covid-19 must comprise an antiviral drug in combination with an inflammation modulator able to regulate the innate immunity system response preserving its regular activity but quenching its overactivation. For all of these reasons a new caspase-1 inhibitor drug could be a useful tool to treat inflammation driven diseases including Covid-19. For this purpose, we have designed a new class of non-covalent, non-peptidic, small molecule caspase-1 inhibitors through structure-based drug design. The multicomponent reaction approach allows the straightforward synthesis of the desired compounds, offering a significant advantage over conventional linear step synthesis by permitting the one pot assembly of very complex structures. This new class of inhibitors shows an IC50 in the low micromolar range, and could be further optimized towards new inflammasome/caspase-1 pathway inhibitors characterized by high bioavailability, potency and reduced toxicity.

Previous studies have investigated the relevance and structure-activity relationships (SARs) of pyrazole derivatives in relation with cannabinoid receptors, and the series of tricyclic 1,4-dihydroindeno[1,2-c]pyrazoles emerged as potent CB2 receptor ligands. In the present study, novel 1,4-dihydroindeno[1,2-c]pyrazole and 1H-benzo[g]indazole carboxamides containing a cyclopropyl or a cyclohexyl substituent were designed and synthesized to evaluate the influence of these structural modifications towards CB1 and CB2 receptor affinities. Among these derivatives, compound 15 (6-cyclopropyl-1-(2,4-dichlorophenyl)-N-(adamantan-1-yl)-1,4-dihydroindeno[1,2-c]pyrazole-3-carboxamide) showed the highest CB2 receptor affinity (Ki = 4 nM) and remarkable selectivity (KiCB1/KiCB2 = 2232), whereas a similar affinity, within the nM range, was seen for the fenchyl derivative (compound 10: Ki = 6 nM), for the bornyl analogue (compound 14: Ki = 38 nM) and, to a lesser extent, for the aminopiperidine derivative (compound 6: Ki = 69 nM). Compounds 10 and 14 were also highly selective for the CB2 receptor (KiCB1/KiCB2 > 1000), whereas compound 6 was relatively selective (KiCB1/KiCB2 = 27). The four compounds were also subjected to GTPγS binding analysis showing antagonist/inverse agonist properties (IC50 for compound 14 = 27 nM, for 15 = 51 nM, for 10 = 80 nM and for 6 = 294 nM), and this activity was confirmed for the three more active compounds in a CB2 receptor-specific in vitro bioassay consisting in the quantification of prostaglandin E2 release by LPS-stimulated BV2 cells, in the presence and absence of WIN55,212-2 and/or the investigated compounds. Modelling studies were also conducted with the four compounds, which conformed with the structural requirements stated for the binding of antagonist compounds to the human CB2 receptor.

Background:In a previous study, we synthesised a new spiroketal derivative, inspired to natural products, that has shown high antiproliferative activity, potent telomerase inhibition and proapoptotic activity on several human cell lines.Objective:This work focused on the study of in vivo antitumor effect of this synthetic spiroketal on a murine melanoma model. In order to shed additional light on the origin of the antitumor effect, in vitro studies were performed.Methods:Spiroketal was administered to B16F10 melanoma mice at a dose of 5 mg/Kg body weight via intraperitoneum at alternate days for 15 days. Tumor volume measures were made every 2 days starting after 12 days from cells injection. The effects of the spiroketal on tumor growth inhibition, apoptosis induction, and cell cycle modification were investigated in vitro on B16 cells. HIF1α gene expression, the inhibition of cells migration and the changes induced in cytoskeleton conformation were evaluated.Results:Spiroketal displayed proapoptotic activity and high antitumor activity in B16 cells with nanomolar IC50. Moreover it has shown to inhibit cell migration, to strongly reduce the HIF1α expression and to induce strongly deterioration of cytoskeleton structure. A potent dose-dependent antitumor efficacy in syngenic B16/C57BL/6J murine model of melanoma was observed with the suppression of tumor growth by an average of 90% at a dose of 5 mg/kg.Conclusion:The synthesized spiroketal shows high antitumor activity in the B16 cells in vitro at nM concentration and a dose-dependent antitumor efficacy in syngenic B16/C57BL/6J mice. The results suggest that this natural product inspired spiroketal may have a potential application in melanoma therapy.

The cholinergic pathways in the central nervous system (CNS) of animals and humans are important for cognitive and behavioural functions. Until a few years ago, it was thought that the key molecules transducing the cholinergic message were the metabotropic muscarinic receptors, but it is now known that ionotropic neuronal nicotinic receptors (nAChRs) are also involved. Based on recent studies, we prepared a small library of novel 3-substituted-3,6-diazabicyclo [3.1.1]heptanes, whose binding activity and functionality have been assayed. Among the synthesized compounds, the 3-(anilino)pyridine series resulted in the most interesting compounds with α

A series of sulfenamide and sulfonamide derivatives was synthesized and evaluated for the affinity at CB1 and CB2 receptors. The N-bornyl-S-(5,6-di-p-tolylpyridazin-3-yl)-sulfenamide, compound 11, displayed good affinity and high selectivity for CB1 receptors (Ki values of 44.6 nM for CB1 receptors and >40 μM for CB2 receptors, respectively). The N-isopinocampheyl-sulfenamide 12 and its sulfonamide analogue 22 showed similar selectivity for CB1 receptors with Ki values of 75.5 and 73.2 nM, respectively. These novel compounds behave as antagonists/inverse agonists at CB1 receptor in the [35S]-GTPγS binding assays, and none showed adequate predictive blood–brain barrier permeation, exhibiting low estimated LD50. However, testing compound 12 in a supraspinal analgesic test (hot-plate) revealed that it was as effective as the classic CB1 receptor antagonist rimonabant, in reversing the analgesic effect of a cannabinoid agonist.

Nuovi approcci terapeutici per la Miastenia Gravis e la Distrofia Muscolare di duchenne, le potenzialità di nuovi inibitori di caspasi-1

The natural-like spiroketal, 2-hydroxy-8-methyl-1,7-dioxaspiro[5.5]undec-3-en-5-one (1) has been synthesised and has shown a potent antitumor activity against human tumor cells of different nature and histotype. We have now performed studies for verify its in vivo activity on a murine melanoma model and in vitro studies to shed some light on the mechanism of action.

A series of sulfenamide and sulfonamide derivatives was synthesized and evaluated for the affinity at CB

The search of new drugs and targets to treat the pain is an intriguing challenge both for several companies and researchers from academia. In this context, since the modulation of the endocannabinoid system with the non selective phytocannabinoid Δ9-THC produces analgesia and potentiates opioid analgesia in animal models, CB2 ligands studies aimed to explore the involvement of endocannabinoid system in management of pain were started. Several selective CB2 receptor agonists exhibited analgesic activity in preclinical models of acute, inflammatory and neuropathic pain, therefore this class of modulators could be useful as analgesic agents for pain, migraine, inflammation and osteoarthritis. This review is an update of our previously manuscript "A survey of recent patents on CB2 agonists in the management of pain" and provides an overview of patents and advances in CB2 agonist studies in the treatment of pain.

We have synthesised and identified a new promising antitumor agent with in vivo activity on a murine melanoma model. Compound 1 showed potent dose-dependent antitumor efficacy in syngenic C57Black mice murine model of melanoma, suppressing the tumor growth by an average of 90% at a dose of 5 mg/kg by intra-peritoneum administration at alternate days for 15 days. It also displayed high antitumor activity in the B16 cells in vitro with nanomolar EC50 value. In addition to the proapoptotic and telomerase inhibition activity, compound 1 has shown to inhibit cell migration and to strongly reduce the HIF1? expression, that is considered a regulator of multiple cellular functions related to the progression from primary to metastatic cancer disease. Therefore, although the full mechanism/s of action of this molecule has yet to be completely elucidated, spiroketal 1 is a promising antitumor drug candidate for the clinical treatment of melanoma and various cancers.

Numerous complex natural products containing spiroketals framework, with a wide range of important biological activities, have been isolated over the years from marine or terrestrial sources. Many groups investigated the possibility to reduce the complexity of spiroketal natural products while preserving their biological activity, showing that simple natural inspired spiroketals can be privileged scaffolds for new interesting lead compounds. We have synthesized a new structurally simplified spiroketal that has shown a potent antitumor activity against tumor cells of different nature and histotype. The simple spiroketalic structure of this compound has three stereocentres and its synthesis afforded a stereoisomeric mixture. We carried out the synthesis and the characterization of the stereoisomeric mixture, the stereoisomeric separation and the biological evaluation both of the stereoisomeric mixture and the enantiomerically pure spiroketals.

New analogues (3a-l) of the previously described α4β2 selective ligand 3-(6-halopyridin-3-yl)-3,6-diazabicyclo[3.1.1]heptanes (2a,b) have been synthesized and their binding activity for neuronal acetylcholine receptor subtypes α4β2 and α7 were assayed. Six of these compounds (3a,b,c,j,k and l) showed high affinity and selectivity for α4β2 receptors. The phenylpyridyl-diazabicycloheptane 3c displayed Ki value of 11.17 pM for α4β2, in line with that of the halogenated homologues 3a,b, although it was characterized by an improved selectivity (Ki = 17 μM for α7 receptors). The influence of substitutions on the phenylpyridyl moiety on binding at both α4β2 and α7 receptors has been examined through the Topliss decision tree analysis. Substitution with electron-donating groups (as CH3 and OCH3) resulted in a good affinity for α4β2 receptors and substantially no affinity for α7. Amongst all the tested phenyl-substituted compounds, the p-NO2-phenyl substituted analogue 3j exhibited the highest α4β2 affinity, with Ki value comparable to that of 3c. Intrinsic α4β2 receptor mediated activity in [(3)H]-DA release assay was showed by compound 3a as well as by the reference analogue 2a, whereas phenyl substituted derivative 3c exhibited α4β2 antagonist activity.

During the last years, there has been a continuous interest in the development of cannabinoid receptor ligands that may serve as therapeutic agents and/or as experimental tools. This prompted us to design and synthesize analogues of the CB2 receptor antagonist N-fenchyl-5-(4-chloro-3-methyl-phenyl)-1-(4-methyl-benzyl)-1H-pyrazole-3-carboxamide (SR144528). The structural modifications involved the bioisosteric replacement of the pyrazole ring by a pyrrole ring and variations on the amine carbamoyl substituents. Two of these compounds, the fenchyl pyrrole analogue 6 and the myrtanyl derivative 10, showed high affinity (Ki in the low nM range) and selectivity for the CB2 receptor and both resulted to be antagonists/inverse agonists in [35S]-GTPγS binding analysis and in an in vitro CB2 receptor bioassay. Cannabinoid receptor binding data of the series allowed identifying steric constraints within the CB2 binding pocket using a study of Van der Waals' volume maps. Glide docking studies revealed that all docked compounds bind in the same region of the CB2 receptor inactive state model., GM acknowledges Regione Autonoma della Sardegna for economic support (grant n. CRP-26417, LR n. 7/2007 and INNOVA.REPOR FESR 2007-2013). PM is recipient of a CSIC fellowship JAEPre- 2010-01119 from Junta para la Ampliacion de Estudios cofinanced by FSE. MGA was recipient of a postdoctoral fellowship from the PICATA Program, CEI-Moncloa. NJ thanks the Spanish Ministry of Economy and Competitivity for the grant SAF2012- 40075, and with JFR the “Programa de Biomedicina, Comunidad de Madrid” (S2011/BMD-2308).

In search of new selective CB2 ligands, the synthesis and preliminary biological evaluation of novel 1,4-dihydroindeno[1,2-c]pyrazole hybrids of the highly potent prototypicals 5-(4-chloro-3-methylphenyl)-1-(4-methylbenzyl)-N-fenchyl-1H-pyrazole-3-carboxamid e 1 and 1-(2,4-dichlorophenyl)-6-methyl-N-(piperidin-1-yl)-1,4-dihydroindeno[1,2-c]pyrazo le-3-carboxamide 2 are detailed.We postulated that the introduction of those pharmacophoric elements essential for activity of 1 in the tricyclic core of 2 might provide CB2 ligands with further improved receptor selectivity and biological activity. Among the compounds, 6-chloro-7-methyl-1-(2,4-dichlorophenyl)-N-fenchyl-1,4-dihydroindeno[1,2-c]pyrazo le-3-carboxamide (22) exhibited low two digit nanomolar affinity for the cannabinoid CB2R and maintained a high level of CB2-selectivity.