Novel quinazolinone derivatives as 5-HT7 receptor ligands

Neuroprotective and Neurite Outgrowth Stimulating Effects of New Low-Basicity 5-HT7 Receptor Agonists: In Vitro Study in Human Neuroblastoma SH-SY5Y Cells

There is some evidence that the serotonin receptor subtype 7 (5-HT7) could be new therapeutic target for neuroprotection. The aim of this study was to compare the neuroprotective and neurite outgrowth potential of new 5-HT7 receptor agonists (AH-494, AGH-238, AGH-194) with 5-CT (5-carboxyamidotryptamine) in human neuroblastoma SH-SY5Y cells. The results revealed that 5-HT7 mRNA expression was significantly higher in retinoic acid (RA)-differentiated cells when compared to undifferentiated ones and it was higher in cell cultured in neuroblastoma experimental medium (DMEM) compared to those placed in neuronal (NB) medium. Furthermore, the safety profile of compounds was favorable for all tested compounds at concentration used for neuroprotection evaluation (up to 1 μM), whereas at higher concentrations (above 10 μM) the one of the tested compounds, AGH-194 appeared to be cytotoxic. While we observed relatively modest protective effects of 5-CT and AH-494 in UN-SH-SY5Y cells cultured in DMEM, in UN-SH-SY5Y cells cultured in NB medium we found a significant reduction of H2O2-evoked cell damage by all tested 5-HT7 agonists. However, 5-HT7-mediated neuroprotection was not associated with inhibition of caspase-3 activity and was not observed in RA-SH-SY5Y cells exposed to H2O2. Furthermore, none of the tested 5-HT7 agonists altered the damage induced by 6-hydroxydopamine (6-OHDA), 1-methyl-4-phenylpyridinium ion (MPP +) and doxorubicin (Dox) in UN- and RA-SH-SY5Y cells cultured in NB. Finally we showed a stimulating effect of AH-494 and AGH-194 on neurite outgrowth. The obtained results provide insight into neuroprotective and neurite outgrowth potential of new 5-HT7 agonists.

Highly Potent and Selective Dopamine D4 Receptor Antagonists Potentially Useful for the Treatment of Glioblastoma

To better understand the role of dopamine D₄ receptor (D₄R) in glioblastoma (GBM), in the present paper, new ligands endowed with high affinity and selectivity for D₄R were discovered starting from the brain penetrant and D₄R selective lead compound 1-(3-(4-phenylpiperazin-1-yl)propyl)-3,4-dihydroquinolin-2(1H)-one (6). In particular, the D₄R antagonist 24, showing the highest affinity and selectivity over D₂R and D₃R within the series (D₂/D₄ = 8318, D₃/D₄ = 3715), and the biased ligand 29, partially activating D₄R G_i-/G_o-protein and blocking β-arrestin recruitment, emerged as the most interesting compounds. These compounds, evaluated for their GBM antitumor activity, induced a decreased viability of GBM cell lines and primary GBM stem cells (GSC#83), with the maximal efficacy being reached at a concentration of 10 μM. Interestingly, the treatment with both compounds 24 and 29 induced an increased effect in reducing the cell viability with respect to temozolomide, which is the first-choice chemotherapeutic drug in GBM.

Therapeutic potential of quinazoline derivatives for Alzheimer's disease: A comprehensive review

Quinazolines are considered as a promising class of bioactive heterocyclic compounds with broad properties. Particularly, the quinazoline scaffold has an impressive role in the design and synthesis of new CNS-active drugs. The drug-like properties and pharmacological characteristics of quinazoline could lead to different drugs with various targets. Among CNS disorders, Alzheimer's disease (AD) is a progressive neurodegenerative disorder with memory loss, cognitive decline and language dysfunction. AD is a complex and multifactorial disease therefore, the need for finding multi-target drugs against this devastative disease is urgent. A literature survey revealed that quinazoline derivatives have diverse therapeutic potential for AD as modulators/inhibitors of β-amyloid, tau protein, cholinesterases, monoamine oxidases, and phosphodiesterases as well as other protective effects. Thus, we describe here the most relevant and recent studies about anti-AD agents with quinazoline structure which can further aid the development and discovery of new anti-AD agents.

Advances in Green Catalysis for the Synthesis of Medicinally Relevant N-Heterocycles

N-heterocycles, both saturated and unsaturated, are ubiquitous biologically active molecules that are extremely appealing scaffolds in drug discovery programs. Although classical synthetic methods have been developed to access many relevant N-heterocyclic scaffolds, representing well-established and reliable routes, some do not meet the needs of sustainability. In this context, several advances have been made towards the sustainable synthesis of N-heterocycles. This review focuses on the most recent examples from the last five years of catalytic synthesis of several heterocyclic compounds of medicinal relevance. Thus, the synthesis of isoindoloquinazolines, quinazolines and azaindoles, among others, are covered. The synthetic methods selected include the use of homogeneous and heterogeneous catalysts and the use of alternative and sustainable methods such as, for example, metal-catalyzed acceptorless coupling and one-pot reactions. The green aspects of the individual synthetic approaches are highlighted, and the scope of each methodology is described.

Sulfonated β-cyclodextrins: efficient supramolecular organocatalysts for diverse organic transformations

The present review summarizes various organic transformations carried out by using sulfonated β-cyclodextrins such as β-cyclodextrin sulfonic acid, β-cyclodextrin propyl sulfonic acid, and β-cyclodextrin butyl sulfonic acid as an efficient, supramolecular reusable catalyst under diverse reaction conditions.

Pharmacology and Therapeutic Potential of the 5-HT7 Receptor

It is well-documented that serotonin (5-HT) exerts its pharmacological effects through a series of 5-HT receptors. The most recently identified member of this family, 5-HT₇, was first identified in 1993. Over the course of the last 25 years, this receptor has been the subject of intense investigation, and it has been demonstrated that 5-HT₇ plays an important role in a wide range of pharmacological processes. As a result of these findings, modulation of 5-HT₇ activity has been the focus of numerous drug discovery and development programs. This review provides an overview of the roles of 5-HT₇ in normal physiology and the therapeutic potential of this interesting drug target.

Antioxidant, anticancer and electrochemical redox properties of new bis(2,3-dihydroquinazolin-4(1H)-one) derivatives

In this paper, a series of bis(2,3-dihydroquinazolin-4(1H)-one) derivatives (4a-i, 10a-k) were synthesized by the one-pot pseudo-five-component reaction of isatoic anhydride with aromatic aldehydes and aromatic amines under reflux in glacial acetic acid. The synthesized compounds were screened for their antioxidant properties using the DPPH radical scavenging method. Compounds 4i and 10h showed potent radical scavenging activities at 20 [Formula: see text] compared to BHA and ascorbic acid. The anticancer activity of compound 4f was evaluated against human breast cancer cell line (MCF 7), and the observed [Formula: see text] was found to be 11.4 [Formula: see text]. The redox behaviour of some analogues was evaluated by cyclic voltammetric methods, and it is found that compound 7d possesses the maximum redox potential.

New N- and O-arylpiperazinylalkyl pyrimidines and 2-methylquinazolines derivatives as 5-HT7 and 5-HT1A receptor ligands: Synthesis, structure-activity relationships, and molecular modeling studies

Based on our earlier studies of structure activity relationships on 4-substituted piperazine derivatives, in this work we synthesized a novel set of long-chain arylpiperazines with the purpose of elucidating if some structural modifications in the terminal fragment could affect the binding affinity for the 5-HT₇ and 5-HT_1A receptors. In this new series, the quinazolinone system of the previous derivatives was replaced by a 6-phenylpyrimidine or a 2-methylquinazoline, which were used as versatile building blocks for the preparation of new compounds. A 4-arylpiperazine moiety through a five methylene chain was anchored at the nitrogen or oxygen atom of the heterocyclic scaffolds. The substituents borne by the piperazine nucleus were phenyl, phenylmethyl, 3- or 4-chlorophenyl, and 2-ethoxyphenyl. Binding tests, performed on human cloned 5-HT₇ and 5-HT_1A receptors, showed that, among the newly synthesized derivatives, 4-[5-[4-(2-ethoxyphenyl)-1-piperazinyl]pentoxy]-6-phenyl-pyrimidine (13) and 3-[5-[4-(2-ethoxyphenyl)-1-piperazinyl]pentyl]-2-methyl-4(3H)-quinazolinone (20) displayed the best affinity values, K_i=23.5 and 8.42nM for 5-HT₇ and 6.96 and 2.99nM for 5-HT_1A receptors, respectively. Moreover, the functional properties for both compounds were further evaluated using the cAMP assay. Finally, a molecular modeling study has been performed for 5-HT₇ and 5-HT_1A receptor homology models to investigate the binding mode of N- and O-alkylated pyrimidinones/pyrimidines 4-13, 2-methylquinazolinones/quinazolines 17-22, and previously reported 2- and 3-substituted quinazolinones 23-30.

Novel N-acyl-carbazole derivatives as 5-HT7R antagonists

To discover a novel 5-HT7R antagonist for treatment of depression, we designed N-acyl-carbazole derivatives which were synthesized and biologically evaluated against 5-HT7R. Among total 30 compounds synthesized, four compounds 27-30 showed good binding affinities with Ki values of <100 nM. The compound 28, 1-(9H-carbazol-9-yl)-6-(4-(2-methoxyphenyl)piperazin-1-yl)hexan-1-one, showed good selectivity over other serotonin receptor subtypes and turned out to be a novel selective 5-HT7R antagonist following functional assays. The compound 28 showed moderate activity on hERG channel and good stability in microsomal stability test. The compound 28 exhibited a good pharmacokinetic profile with 67.8% oral bioavailability and good penetration to the brain. The compound 28 was also tested in in vivo depression animal model and showed antidepressant effect in the forced swimming test. Therefore, the selective 5-HT7R antagonist 28 can be considered as a good lead for discovery of novel 5-HT7R antagonists as antidepressants.

Access to enhanced catalytic core–shell CuO–Pd nanoparticles for the organic transformations

This paper describes the biosynthesis of core–shell CuO–Pd nanocatalysts with the aid of a Cyperus rotundus rhizome extract.

Novel N-biphenyl-2-ylmethyl 2-methoxyphenylpiperazinylalkanamides as 5-HT7R antagonists for the treatment of depression

5-HT7 receptor (5-HT7R) is a promising target for the treatment of depression and neuropathic pain. 5-HT7R antagonists exhibited antidepressant effects, while the agonists produced strong anti-hyperalgesic effects. In our efforts to discover selective 5-HT7R antagonists or agonists, N-biphenylylmethyl 2-methoxyphenylpiperazinylalkanamides 1 were designed, synthesized, and biologically evaluated against 5-HT7R. Among the synthesized compounds, N-2'-chlorobiphenylylmethyl 2-methoxyphenylpiperazinylpentanamide 1-8 showed the best binding affinity with a Ki value of 8.69nM and it was verified as a novel antagonist according to functional assays. The compound 1-8 was very selective over 5-HT1DR, 5-HT2AR, 5-HT3R, 5-HT5AR and 5-HT6R and moderately selective over 5-HT1AR, 5-HT1BR and 5-HT2CR. The novel 5-HT7R antagonist 1-8 exhibited an antidepressant effect at a dose of 25mg/kg in the forced swimming test in mice and showed a U-shaped dose-response curve which typically appears in 5-HT7R antagonists such as SB-269970 and lurasidone.

Silver decorated multi-walled carbon nanotubes as a heterogeneous catalyst in the sonication of 2-aryl-2,3-dihydroquinazolin-4(1H)-ones

The silver nanoparticles supported on CNTs have been introduced as a novel catalyst in the synthesis of quinazolinones under sonication. The experiments established reusability of the catalyst, excellent yields, short reaction time, and simple work-up procedures.

Design of novel quinazolinone derivatives as inhibitors for 5HT7 receptor

To study the pharmacophore properties of quinazolinone derivatives as 5HT(7) inhibitors, 3D QSAR methodologies, namely Comparative Molecular Field Analysis (CoMFA) and Comparative Molecular Similarity Indices Analysis (CoMSIA) were applied, partial least square (PLS) analysis was performed and QSAR models were generated. The derived model showed good statistical reliability in terms of predicting the 5HT(7) inhibitory activity of the quinazolione derivative, based on molecular property fields like steric, electrostatic, hydrophobic, hydrogen bond donor and hydrogen bond acceptor fields. This is evident from statistical parameters like q(2) (cross validated correlation coefficient) of 0.642, 0.602 and r(2) (conventional correlation coefficient) of 0.937, 0.908 for CoMFA and CoMSIA respectively. The predictive ability of the models to determine 5HT(7) antagonistic activity is validated using a test set of 26 molecules that were not included in the training set and the predictive r(2) obtained for the test set was 0.512 & 0.541. Further, the results of the derived model are illustrated by means of contour maps, which give an insight into the interaction of the drug with the receptor. The molecular fields so obtained served as the basis for the design of twenty new ligands. In addition, ADME (Adsorption, Distribution, Metabolism and Elimination) have been calculated in order to predict the relevant pharmaceutical properties, and the results are in conformity with required drug like properties.

Pharmacological blockade of 5-HT7 receptors as a putative fast acting antidepressant strategy

Current antidepressants still display unsatisfactory efficacy and a delayed onset of therapeutic action. Here we show that the pharmacological blockade of serotonin 7 (5-HT(7)) receptors produced a faster antidepressant-like response than the commonly prescribed antidepressant fluoxetine. In the rat, the selective 5-HT(7) receptor antagonist SB-269970 counteracted the anxiogenic-like effect of fluoxetine in the open field and exerted an antidepressant-like effect in the forced swim test. In vivo, 5-HT(7) receptors negatively regulate the firing activity of dorsal raphe 5-HT neurons and become desensitized after long-term administration of fluoxetine. In contrast with fluoxetine, a 1-week treatment with SB-269970 did not alter 5-HT firing activity but desensitized cell body 5-HT autoreceptors, enhanced the hippocampal cell proliferation, and counteracted the depressive-like behavior in olfactory bulbectomized rats. Finally, unlike fluoxetine, early-life administration of SB-269970, did not induce anxious/depressive-like behaviors in adulthood. Together, these findings indicate that the 5-HT(7) receptor antagonists may represent a new class of antidepressants with faster therapeutic action.

Serotonin 5-HT7 receptor agents: Structure-activity relationships and potential therapeutic applications in central nervous system disorders

Since its discovery in the 1940s in serum, the mammalian intestinal mucosa, and in the central nervous system, serotonin (5-HT) has been shown to be involved in virtually all cognitive and behavioral human functions, and alterations in its neurochemistry have been implicated in the etiology of a plethora of neuropsychiatric disorders. The cloning of 5-HT receptor subtypes has been of importance in enabling them to be classified as specific protein molecules encoded by specific genes. The 5-HT(7) receptor is the most recently classified member of the serotonin receptor family. Since its identification, it has been the subject of intense research efforts driven by its presence in functionally relevant regions of the brain. The availability of some selective antagonists and agonists, in combination with genetically modified mice lacking the 5-HT(7) receptor, has allowed for a better understanding of the pathophysiological role of this receptor. This paper reviews data on localization and pharmacological properties of the 5-HT(7) receptor, and summarizes the results of structure-activity relationship studies aimed at the discovery of selective 5-HT(7) receptor ligands. Additionally, an overview of the potential therapeutic applications of 5-HT(7) receptor agonists and antagonists in central nervous system disorders is presented.

2-(4-Bromo-phen-yl)-2-methyl-2,3-di-hydro-quinazolin-4(1H)-one

In the title compound, C₁₅H₁₃BrN₂O, the pyrimidine ring adopts a skew boat conformation. The amino H atom forms an inter­molecular hydrogen bond with the carbonyl O atom of an adjacent mol­ecule, forming an inversion dimer. Another lone pair of electrons on the same carbonyl O atom acts as acceptor for another N—H⋯O inter­molecular hydrogen bond with a neighbouring mol­ecule, forming chains along the c axis.