Naphthylisopropylamine and N-benzylamphetamine derivatives as monoamine oxidase inhibitors

7H-Pyrrolo[2,3-d]pyrimidine-4-amines as Potential Inhibitors of Plasmodium falciparum Calcium-Dependent Protein Kinases

A series of pyrrolo[2,3-d]pyrimidines were designed in silico as potential bumped kinase inhibitors targeting P. falciparum calcium dependent protein kinase 4 (PfCDPK4), with the potential to inhibit PfCDPK1 based on earlier studies of the two kinases. A small series of these compounds were prepared and assessed for inhibitory activity against PfCDPK4 and PfCDPK1 in vitro. Four of the compounds displayed promising inhibitory activity against either PfCDPK4 (IC₅₀ =0.210-0.530 μM), or PfCDPK1 (IC₅₀ =0.589 μM). These data will enable optimisation of the molecular model to better predict inhibitory activity against PfCDPK4.

Enantioselective Synthesis of 3-Aryl-3-hydroxypropanoic Esters as Subunits for Chiral Liquid Crystals

Chiral liquid crystals (LCs) with their unique optical and mechanical properties are perspective functional soft materials for fundamental science and advanced technological applications. Herein, we introduce the chiral 3-aryl-3-hydroxypropanoic ester moiety as a versatile building block for the preparation of LC compounds. Three chiral subunits differing in the aromatic part were obtained through asymmetric transfer hydrogenation using Ru(II) complexes with ee from 98% to >99%. Chiral LC compounds of diverse topologies were further prepared without deterioration of the ee during the synthesis. The mesomorphic behavior of rod-shaped, bent-shaped flexible dimeric, and polycatenar LCs is consistent with their topology─chiral nematic and smectic phases were identified as well as the rarely observed twist grain boundary A and blue phases. The utilization of synthetic chiral building blocks offers the possibility of fine tuning the intermolecular interactions by subtle changes in the molecular structure as well as the preparation of the corresponding racemic forms. This paves the way for the study of self-organization and the structure-property relationship in chiral soft materials.

Acid-Mediated Decarboxylative C–H Coupling between Arenes and O-Allyl Carbamates

Treatment of O-allyl N-tosyl carbamates with aromatic compounds in the presence of Cu(OTf)2 or TMSOTf as promoters, affords N-substituted 1-arylpropan-2-amines, 1,2-diarylpropanes, 1,1-diarylpropanes, or indanes, depending on the nature of the...

Enantioselective Chromatographic Separation and Lipase Catalyzed Asymmetric Resolution of Biologically Important Chiral Amines

Cyanoacetamides are vital synthons in synthetic organic chemistry. However, methods to enantiopure cyanoacetamides have not yet been well explored. In this work, the preparation of cyanoacetamide synthons RS-(1a–4a) or methoxyacetamides RS-(1b–4b) in enantiopure/enriched form was investigated. Compounds S-1, S-2, R-1b, R-1a, andR-2b were prepared in enantiopure form (ee > 99%) while compounds S-4, R-2a, and R-4a were achieved in ee 9%, 80%, and 76%, respectively. Many baselines enantioselective HPLC separations of amines 1–4, their cyanoacetamides (1a–4a), and methoxyacetamides (1b–4b) were achieved by utilizing diverse mobile-phase compositions and two cellulose-based CSPs (ODH® and LUX-3® columns). Such enantioselective HPLC separations were used to monitor the lipase-catalyzed kinetic resolution of amines RS-(1–4).

Coumarin-Chalcone Hybrids as Inhibitors of MAO-B: Biological Activity and In Silico Studies

Fourteen coumarin-derived compounds modified at the C3 carbon of coumarin with an α,β-unsaturated ketone were synthesized. These compounds may be designated as chalcocoumarins (3-cinnamoyl-2H-chromen-2-ones). Both chalcones and coumarins are recognized scaffolds in medicinal chemistry, showing diverse biological and pharmacological properties among which neuroprotective activities and multiple enzyme inhibition, including mitochondrial enzyme systems, stand out. The evaluation of monoamine oxidase B (MAO-B) inhibitors has aroused considerable interest as therapeutic agents for neurodegenerative diseases such as Parkinson's. Of the fourteen chalcocumarins evaluated here against MAO-B, ChC4 showed the strongest activity in vitro, with IC₅₀ = 0.76 ± 0.08 µM. Computational docking, molecular dynamics and MM/GBSA studies, confirm that ChC4 binds very stably to the active rMAO-B site, explaining the experimental inhibition data.

Synthesis and antitumor effects of novel benzyl naphthyl sulfoxide/sulfone derivatives derived from Rigosertib

In this work, a series of novel benzyl naphthyl sulfoxides/sulfones derived from Rigosertib were designed and synthesized as potential antitumor agents. The in vitro cytotoxicity against four human cancer cell lines (HeLa, MCF-7, HepG2 and SCC-15) and two normal human cell lines (HUVEC and 293T) indicated that some of the sulfones and sulfoxides possessed potent antineoplastic activity that reached nanomolar levels and relatively low toxicity to normal cells. Among them, (2-methoxy-5-((naphthalen-2-ylsulfonyl)methyl)phenyl)glycine (15b) was found to be a promising antitumor drug candidate that could significantly inhibit tumor cell migration and induce tumor cell apoptosis via the p53-Bcl-2-Bax signaling pathway at nanomolar concentrations.

In this work, a series of novel benzyl naphthyl sulfoxides/sulfones derived from Rigosertib were designed and synthesized as potential antitumor agents.

Engaging Sulfonamides: Intramolecular Cross-Electrophile Coupling Reaction of Sulfonamides with Alkyl Chlorides

The application of amine derivatives as coupling partners is rare due to the inherent strength of the C-N bond. Herein, we report the first cross-electrophile coupling reaction of unstrained benzylic sulfonamides. Nickel-catalyzed intramolecular cross-electrophile coupling reactions of acyclic and cyclic benzylic sulfonamides with pendant alkyl chlorides generate cyclopropane products. Mechanistic experiments and DFT calculations are consistent with initiation of the reaction by magnesium iodide accelerated oxidative addition of the benzylic sulfonamide. This work establishes neutral and unstrained amine derivatives as XEC partners, furnishes structural rearrangement of benzylic sulfonamides, and provides valuable information regarding catalyst design for the development of new cross-electrophile coupling reactions of carbon-heteroatom bonds.

Amphetamine Derivatives as Monoamine Oxidase Inhibitors

Amphetamine and its derivatives exhibit a wide range of pharmacological activities, including psychostimulant, hallucinogenic, entactogenic, anorectic, or antidepressant effects. The mechanisms of action underlying these effects are usually related to the ability of the different amphetamines to interact with diverse monoamine transporters or receptors. Moreover, many of these compounds are also potent and selective monoamine oxidase inhibitors. In the present work, we review how structural modifications on the aromatic ring, the amino group and/or the aliphatic side chain of the parent scaffold, modulate the enzyme inhibitory properties of hundreds of amphetamine derivatives. Furthermore, we discuss how monoamine oxidase inhibition might influence the pharmacology of these compounds.

Insight of Captagon Abuse by Chemogenomics Knowledgebase-guided Systems Pharmacology Target Mapping Analyses

Captagon, known by its genetic name Fenethylline, is an addictive drug that complicates the War on Drugs. Captagon has a strong CNS stimulating effect than its primary metabolite, Amphetamine. However, multi-targets issues associated with the drug and metabolites as well as its underlying mechanisms have not been fully defined. In the present work, we applied our established drug-abuse chemogenomics-knowledgebase systems pharmacology approach to conduct targets/off-targets mapping (SP-Targets) investigation of Captagon and its metabolites for hallucination addiction, and also analyzed the cell signaling pathways for both Amphetamine and Theophylline with data mining of available literature. Of note, Amphetamine, an agonist for trace amine-associated receptor 1 (TAAR1) with enhancing dopamine signaling (increase of irritability, aggression, etc.), is the main cause of Captagon addiction; Theophylline, an antagonist that blocks adenosine receptors (e.g. A2aR) in the brain responsible for restlessness and painlessness, may attenuate the behavioral sensitization caused by Amphetamine. We uncovered that Theophylline's metabolism and elimination could be retarded due to competition and/or blockage of the CYP2D6 enzyme by Amphetamine; We also found that the synergies between these two metabolites cause Captagon's psychoactive effects to act faster and far more potently than those of Amphetamine alone. We carried out further molecular docking modeling and molecular dynamics simulation to explore the molecular interactions between Amphetamine and Theophylline and their important GPCRs targets, including TAAR1 and adenosine receptors. All of the systems pharmacology analyses and results will shed light insight into a better understanding of Captagon addiction and future drug abuse prevention.

3D-QSAR and in-silico Studies of Natural Products and Related Derivatives as Monoamine Oxidase Inhibitors

BACKGROUND

The computational development of human monoamine oxidase (MAO) inhibitors led to advancement in drug design and the treatment of many neurodegenerative diseases and neuropsychiatric disorders. The computational development of human monoamine oxidase (MAO) inhibitors led to advancement in drug design and the treatment of many neurodegenerative diseases and neuropsychiatric disorders. Different natural heterocyclic structures are reported to display selective MAO inhibitory activity by preclinical and in-silico modeling.

OBJECTIVE

Currently, the major interest is devoted to the study of natural based therapeutic agents from the different categories. Therefore, we presenting the review to critically discuss and outline the recent advances in our knowledge on the importance of natural and natural based ligand-MAO insilico methods for novel MAO inhibitors.

DISCUSSION

Several natural and related synthetic heterocyclic compounds such as coumarins, β- carboline, piperine, naphthoquinone, morpholine, caffeine, amphetamine moreover flavonoids, chalcones, xanthones, curcumin are discussed for their MAO inhibitory profile along with molecular docking and quantitative structure-activity relationship studies.

CONCLUSION

It is clear that, by this computational drug design approach, more particular, reversible and potent compounds can be proposed as MAO inhibitors by exact changes on the fundamental framework.

Synthesis and radioprotective effects of novel benzyl naphthyl sulfoxide (sulfone) derivatives transformed from Ex-RAD

In this work, a series of novel benzyl naphthyl sulfoxides (sulfones) derived from Ex-RAD were designed and synthesized as potential radioprotective agents. Some of the compounds considerably protected HUVECs against 60Co γ-irradiation, accompanied by the absence of cytotoxicity. Compared to Ex-RAD, compound 8n not only exhibited a significant protective effect on cell survival and radiation-induced DNA damage, but also remarkably enhanced the survival (100%) of mice in 30 days after being exposed to irradiation. The results suggested that some target compounds are valuable for further research as promising radioprotectors.

Privileged scaffolds as MAO inhibitors: Retrospect and prospects

This review aims to be a comprehensive, authoritative, critical, and readable review of general interest to the medicinal chemistry community because it focuses on the pharmacological, chemical, structural and computational aspects of diverse chemical categories as monoamine oxidase inhibitors (MAOIs). Monoamine oxidases (MAOs), namely MAO-A and MAO-B represent an enormously valuable class of neuronal enzymes embodying neurobiological origin and functions, serving as potential therapeutic target in neuronal pharmacotherapy, and hence we have coined the term "Neurozymes" which is being introduced for the first time ever. Nowadays, therapeutic attention on MAOIs engrosses two imperative categories; MAO-A inhibitors, in certain mental disorders such as depression and anxiety, and MAO-B inhibitors, in neurodegenerative disorders like Alzheimer's disease (AD) and Parkinson's disease (PD). The use of MAOIs declined due to some potential side effects, food and drug interactions, and introduction of other classes of drugs. However, curiosity in MAOIs is reviving and the recent developments of new generation of highly selective and reversible MAOIs, have renewed the therapeutic prospective of these compounds. The initial section of the review emphasizes on the detailed classification, structural and binding characteristics, therapeutic potential, current status and future challenges of the privileged pharmacophores. However, the chemical prospective of privileged scaffolds such as; aliphatic and aromatic amines, amides, hydrazines, azoles, diazoles, tetrazoles, indoles, azines, diazines, xanthenes, tricyclics, benzopyrones, and more interestingly natural products, along with their conclusive SARs have been discussed in the later segment of review. The last segment of the article encompasses some patents granted in the field of MAOIs, in a simplistic way.

Synthesis and Cytotoxicity of N-Substituted Dibenzo[a,j]xanthene-3,11-dicarboxamide Derivatives

In order to study the structure-activity relationships of xanthene derivatives, four series of N-substituted 14-aryl-14H-dibenzo[a,j]xanthene-3,11-dicarboxamide derivatives were synthesized. The structures of all compounds were identified by ¹H-NMR, HR-MS and IR spectra, in which compounds 6a-h were further identified by ¹³C-NMR spectra. The in vitro antitumor activity of the synthesized compounds was tested by MTT assay. Most of them displayed strong inhibitory activity on human hepatocellular carcinoma cell lines (SK-HEP-1, HepG2 and SMMC-7721 cells) and acute promyelocytic leukemia NB4 cells. Compounds 6c-6e exhibited significant inhibitory activity against NB4 cells with IC₅₀ values of 0.52 μM and 0.76 μM, respectively, much lower than 5.31 μM of the positive control As₂O₃.

Catalytic asymmetric Tamura cycloadditions involving nitroalkenes

The first examples of asymmetric Tamura cycloaddition reactions involving singly activated alkenes are reported.

Arylthiosemicarbazones as antileishmanial agents

Based on a screening process, we targeted substituted thiosemicarbazone as potential antileishmanial agents. Our objective was to identify the key structural elements contributing to the anti-parasite activity that might be used for development of effective drugs. A series of 32 compounds was synthesized and their efficacy was evaluated against the clinically relevant intracellular amastigotes of Leishmania donovani. From these, 22 compounds showed EC50 values below 10 μM with the most active derivative (compound 14) showing an EC50 of 0.8 μM with very low toxicity on two different mammalian cell lines. The most relevant structural elements required for higher activity indicate that the presence of a fused bicyclic aromatic ring such as a naphthalene bearing an alkyl or an alkoxy group substituent are prerequisites. Owing to the easy synthesis, high activity and low toxicity, the most active compounds could be considered as a lead for further development.

Computer-aided (in silico) approaches in the mode-of-action analysis and safety assessment of ostarine and 4-methylamphetamine

OBJECTIVE

This study exemplifies computer-aided (in silico) approaches in assessing the risks of new psychoactive substances emerging in the European Union. In this work, we (i) consider the potential of Ostarine exhibiting psychoactivity and (ii) anticipate potential activities and toxicities of 4-methylamphetamine.

METHOD

The approach, termed in silico target prediction, suggests potential protein targets modulated by compounds given their chemical structure. This is achieved by first establishing the associations between chemical structure and protein targets using data from the bioactivity database, ChEMBL, via the use of two different computational algorithms. On the basis of the associations, protein targets and consequently the mode of action of novel compounds were predicted.

RESULTS

For Ostarine, none of the targets anticipated are currently known to elicit psychoactivity. Furthermore, Ostarine is unlikely to cross the blood-brain barrier to reach relevant target sites on the basis of its physicochemical properties. For 4-methylamphetamine, toxicities were anticipated, that is, serotonin syndrome (based on the prediction of SERT) and other effects similar to related substances, that is, methamphetamine.

CONCLUSION

From the two case studies, we showed that in silico target prediction appears to have potential in assessing new psychoactive compounds where experimental data are scarce. The applicability domain of target predictions when applied to psychoactive compounds needs to be established in future work.

Profiling 976 ToxCast chemicals across 331 enzymatic and receptor signaling assays

Understanding potential health risks is a significant challenge due to the large numbers of diverse chemicals with poorly characterized exposures and mechanisms of toxicities. The present study analyzes 976 chemicals (including failed pharmaceuticals, alternative plasticizers, food additives, and pesticides) in Phases I and II of the U.S. EPA's ToxCast project across 331 cell-free enzymatic and ligand-binding high-throughput screening (HTS) assays. Half-maximal activity concentrations (AC50) were identified for 729 chemicals in 256 assays (7,135 chemical-assay pairs). Some of the most commonly affected assays were CYPs (CYP2C9 and CYP2C19), transporters (mitochondrial TSPO, norepinephrine, and dopaminergic), and GPCRs (aminergic). Heavy metals, surfactants, and dithiocarbamate fungicides showed promiscuous but distinctly different patterns of activity, whereas many of the pharmaceutical compounds showed promiscuous activity across GPCRs. Literature analysis confirmed >50% of the activities for the most potent chemical-assay pairs (54) but also revealed 10 missed interactions. Twenty-two chemicals with known estrogenic activity were correctly identified for the majority (77%), missing only the weaker interactions. In many cases, novel findings for previously unreported chemical-target combinations clustered with known chemical-target interactions. Results from this large inventory of chemical-biological interactions can inform read-across methods as well as link potential targets to molecular initiating events in adverse outcome pathways for diverse toxicities.

Design, synthesis and anticancer activity of N(3),N(11)-bis(2-hydroxyethyl)-14-aryl-14H-dibenzo[a,j]xanthenes-3,11-dicarboxamide

A series of novel N(3),N(11)-bis(2-hydroxyethyl)-14-aryl-14H-dibenzo[a,j]xanthenes-3,11-dicarboxamide, three N(3),N(11)-bis(2-hydroxyethyl)-14-aryl-14H-dibenzo[a,j]xanthene-3,11-dimethanamine derivatives and their intermediates 14-aryl-14H-dibenzo[a,j]xanthenes-3,11-dicarboxylic acid, were synthesized, and the structures of which were characterized by (1)H-NMR, (13)C-NMR, high resolution (HR)-MS, and IR spectra. The antitumor activities of these molecules were evaluated on five cancer cell lines. The results of in vitro assay against human hepatocellular carcinoma cell lines (SK-HEP-1 and HepG2 and SMMC-7721 cells), acute promyelocytic leukemia NB4 cells and uterine cervix cancer HeLa cells, show several compounds to be endowed with cytotoxicity in micromolar to submicromolar range. The carboxamide derivatives 6c and 6e exhibitted good inhibition on NB4 cancer cells, and the IC(50) values of which were 0.82 µM and 0.96 µM, respectively, much lower than 5.01 µM of the positive control As(2)O(3). Flow cytometric analysis results revealed that compounds 6e and 6f may induce tumor cell apoptosis.

2-Arylthiomorpholine derivatives as potent and selective monoamine oxidase B inhibitors

2-Arylthiomorpholine and 2-arylthiomorpholin-5-one derivatives, designed as rigid and/or non-basic phenylethylamine analogues, were evaluated as rat and human monoamine oxidase inhibitors. Molecular docking provided insight into the binding mode of these inhibitors and rationalized their different potencies. Making the phenylethylamine scaffold rigid by fixing the amine chain in an extended six-membered ring conformation increased MAO-B (but not MAO-A) inhibitory activity relative to the more flexible alpha-methylated derivative. The presence of a basic nitrogen atom is not a prerequisite in either MAO-A or MAO-B. The best K(i) values were in the 10(-8)M range, with selectivities towards human MAO-B exceeding 2000-fold.