11 pages, 1804 KB  
Article
Vinylation of a Secondary Amine Core with Calcium Carbide for Efficient Post-Modification and Access to Polymeric Materials
by Konstantin S. Rodygin, Alexander S. Bogachenkov and Valentine P. Ananikov
Molecules 2018, 23(3), 648; https://doi.org/10.3390/molecules23030648 - 13 Mar 2018
Cited by 38 | Viewed by 9038
Abstract
We developed a simple and efficient strategy to access N-vinyl secondary amines of various naturally occurring materials using readily available solid acetylene reagents (calcium carbide, KF, and KOH). Pyrrole, pyrazole, indoles, carbazoles, and diarylamines were successfully vinylated in good yields. Cross-linked and [...] Read more.
We developed a simple and efficient strategy to access N-vinyl secondary amines of various naturally occurring materials using readily available solid acetylene reagents (calcium carbide, KF, and KOH). Pyrrole, pyrazole, indoles, carbazoles, and diarylamines were successfully vinylated in good yields. Cross-linked and linear polymers were synthesized from N-vinyl carbazoles through free radical and cationic polymerization. Post-modification of olanzapine (an antipsychotic drug substance) was successfully performed. Full article
(This article belongs to the Special Issue Alkynes: From Reaction Design to Applications in Organic Synthesis)
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14 pages, 2591 KB  
Article
Ruthenium(η61-arene-CH2-NHC) Catalysts for Direct Arylation of 2-Phenylpyridine with (Hetero)Aryl Chlorides in Water
by Nazan Kaloğlu, İsmail Özdemir, Nevin Gürbüz, Hakan Arslan and Pierre H. Dixneuf
Molecules 2018, 23(3), 647; https://doi.org/10.3390/molecules23030647 - 13 Mar 2018
Cited by 24 | Viewed by 5178
Abstract
A series of new benzimidazolium halides were synthesized in good yields as unsymmetrical N-heterocyclic carbene (NHC) precursors containing the N–CH2–arene group. The benzimidazolium halides were readily converted into ruthenium(II)–NHC complexes with the general formula [RuCl261 [...] Read more.
A series of new benzimidazolium halides were synthesized in good yields as unsymmetrical N-heterocyclic carbene (NHC) precursors containing the N–CH2–arene group. The benzimidazolium halides were readily converted into ruthenium(II)–NHC complexes with the general formula [RuCl261–arene–CH2–NHC)]. The structures of all new compounds were characterized by 1H NMR (Nuclear Magnetic Resonance), 13C NMR, FT-IR (Fourier Transform Infrared) spectroscopy and elemental analysis techniques. The single crystal structure of one benzimidazole ruthenium complex, 2b, was determined. The complex is best thought of as containing an octahedrally coordinated Ru center with the arene residue occupying three sites, the remaining sites being occupied by a (carbene)C–Ru bond and two Ru–Cl bonds. The catalytic activity of [RuCl261–arene–CH2–NHC)] complexes was evaluated in the direct (hetero)arylation of 2-phenylpyridine with (hetero)aryl chlorides in water as the nontoxic reaction medium. These results show that catalysts 2a and 2b were the best for monoarylation with simple phenyl and tolyl chlorides. For functional aryl chlorides, 2d, 2e, and 2c appeared to be the most efficient. Full article
(This article belongs to the Special Issue Organometallic Catalysis in Organic Synthesis)
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31 pages, 5373 KB  
Review
Structural Diversity and Biological Activities of Novel Secondary Metabolites from Endophytes
by Han Gao, Gang Li and Hong-Xiang Lou
Molecules 2018, 23(3), 646; https://doi.org/10.3390/molecules23030646 - 13 Mar 2018
Cited by 107 | Viewed by 11907
Abstract
Exploration of structurally novel natural products greatly facilitates the discovery of biologically active pharmacophores that are biologically validated starting points for the development of new drugs. Endophytes that colonize the internal tissues of plant species, have been proven to produce a large number [...] Read more.
Exploration of structurally novel natural products greatly facilitates the discovery of biologically active pharmacophores that are biologically validated starting points for the development of new drugs. Endophytes that colonize the internal tissues of plant species, have been proven to produce a large number of structurally diverse secondary metabolites. These molecules exhibit remarkable biological activities, including antimicrobial, anticancer, anti-inflammatory and antiviral properties, to name but a few. This review surveys the structurally diverse natural products with new carbon skeletons, unusual ring systems, or rare structural moieties that have been isolated from endophytes between 1996 and 2016. It covers their structures and bioactivities. Biosynthesis and/or total syntheses of some important compounds are also highlighted. Some novel secondary metabolites with marked biological activities might deserve more attention from chemists and biologists in further studies. Full article
(This article belongs to the Collection Bioactive Compounds)
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11 pages, 4638 KB  
Article
Anti-Inflammatory and Tissue Regenerative Effects of Topical Treatment with Ozonated Olive Oil/Vitamin E Acetate in Balanitis Xerotica Obliterans
by Monica Currò, Tiziana Russo, Nadia Ferlazzo, Daniela Caccamo, Pietro Antonuccio, Salvatore Arena, Saveria Parisi, Patrizia Perrone, Riccardo Ientile, Carmelo Romeo and Pietro Impellizzeri
Molecules 2018, 23(3), 645; https://doi.org/10.3390/molecules23030645 - 13 Mar 2018
Cited by 39 | Viewed by 11068
Abstract
Balanitis xerotica obliterans (BXO) is a chronic inflammatory skin disorder, considered the male genital variant of lichen sclerosus. Anti-inflammatory drugs are commonly used in BXO. We evaluated the effects of an innovative formulation of ozonated olive oil with vitamin E acetate (OZOILE® [...] Read more.
Balanitis xerotica obliterans (BXO) is a chronic inflammatory skin disorder, considered the male genital variant of lichen sclerosus. Anti-inflammatory drugs are commonly used in BXO. We evaluated the effects of an innovative formulation of ozonated olive oil with vitamin E acetate (OZOILE®) on the inflammatory status and tissue remodeling in male children with BXO. The mRNA transcripts of proteins involved either in inflammation or in dynamics of tissue regeneration were analyzed by quantitative real-time PCR, in foreskins affected by BXO removed from patients untreated or treated with OZOILE® cream for 7 days before circumcision. We found a significant reduction in mRNA levels of IL-1β, TNF-α, INF–γ, transglutaminase 2 and NOS2 in foreskins treated with OZOILE® in comparison to untreated ones (p < 0.001). No significant differences were observed in NF-κB activation in the specimens obtained from treated and untreated patients. Hence, OZOILE® treatment up-regulated hypoxia-inducible factor (HIF)-1alpha, vascular endothelial growth factor (VEGF) and E-cadherin gene expression (p < 0.001). The treatment with OZOILE® showed effective results in children affected by BXO by reducing the inflammatory process and stimulating mechanisms for tissue regeneration of the foreskin. A randomized clinical trial on a large number of children affected by BXO might be useful to verify the efficacy of topical treatment with OZOILE®. Full article
(This article belongs to the Section Medicinal Chemistry)
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13 pages, 4029 KB  
Article
The Effect of Tomatine on Gene Expression and Cell Monolayer Integrity in Caco-2
by Mattia P. Arena, Coen Govers, Concetta Lotti, Luigi Ricciardi, Harry J. Wichers and Jurriaan J. Mes
Molecules 2018, 23(3), 644; https://doi.org/10.3390/molecules23030644 - 13 Mar 2018
Cited by 12 | Viewed by 6572
Abstract
More understanding of the risk-benefit effect of the glycoalkaloid tomatine is required to be able to estimate the role it might play in our diet. In this work, we focused on effects towards intestinal epithelial cells based on a Caco-2 model in order [...] Read more.
More understanding of the risk-benefit effect of the glycoalkaloid tomatine is required to be able to estimate the role it might play in our diet. In this work, we focused on effects towards intestinal epithelial cells based on a Caco-2 model in order to analyze the influence on the cell monolayer integrity and on the expression levels of genes involved in cholesterol/sterol biosynthesis (LDLR), lipid metabolism (NR2F2), glucose and amino acid uptake (SGLT1, PAT1), cell cycle (PCNA, CDKN1A), apoptosis (CASP-3, BMF, KLF6), tight junctions (CLDN4, OCLN2) and cytokine-mediated signaling (IL-8, IL1β, TSLP, TNF-α). Furthermore, since the bioactivity of the compound might vary in the presence of a food matrix and following digestion, the influence of both pure tomatine and in vitro digested tomatine with and without tomato fruit matrix was studied. The obtained results suggested that concentrations <20 µg/mL of tomatine, either undigested or in vitro digested, do not compromise the viability of Caco-2 cells and stimulate cytokine expression. This effect of tomatine, in vitro digested tomatine or in vitro digested tomatine with tomato matrix differs slightly, probably due to variations of bioactivity or bioavailability of the tomatine. The results lead to the hypothesis that tomatine acts as hormetic compound that can induce beneficial or risk toxic effects whether used in low or high dose. Full article
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11 pages, 1241 KB  
Article
Comparison of Multiple Bioactive Constituents in Different Parts of Eucommia ulmoides Based on UFLC-QTRAP-MS/MS Combined with PCA
by Ying Yan, Hui Zhao, Cuihua Chen, Lisi Zou, Xunhong Liu, Chuan Chai, Chengcheng Wang, Jingjing Shi and Shuyu Chen
Molecules 2018, 23(3), 643; https://doi.org/10.3390/molecules23030643 - 13 Mar 2018
Cited by 56 | Viewed by 6066
Abstract
Eucommia ulmoides Oilv. (EU), also called Du-zhong, is a classical traditional Chinese medicine. Its bark, leaf, and male flower are all used for medicinal purposes, called Eucommiae Cortex (EC), Eucommiae Folium (EF), and Eucommiae Flos Male (EFM). In order to study the difference [...] Read more.
Eucommia ulmoides Oilv. (EU), also called Du-zhong, is a classical traditional Chinese medicine. Its bark, leaf, and male flower are all used for medicinal purposes, called Eucommiae Cortex (EC), Eucommiae Folium (EF), and Eucommiae Flos Male (EFM). In order to study the difference in synthesis and the accumulation of metabolites in different parts of EU, a reliable method based on ultra-fast liquid chromatography tandem triple quadrupole mass spectrometry (UFLC-QTRAP-MS/MS) was developed for the simultaneous determination of a total of 21 constituents, including two lignans, 6 iridoids, 6 penylpropanoids, 6 flavonoids, and one phenol in the samples (EC, EF, and EFM). Furthermore, principal component analysis (PCA) was performed to evaluate and classify the samples according to the contents of these 21 constituents. All of the results demonstrated that the chemical compositions in EC, EF, and EFM were significantly different and the differential constituents (i.e., aucubin, geniposidic acid, chlorogenic acid, pinoresinol-di-O-β-d-glucopyranoside, geniposide, cryptochlorogenic acid, rutin, and quercetin) were remarkably associated with sample classifications. The research will provide the basic information for revealing the laws of metabolite accumulation in EC, EF, and EFM from the same origin. Full article
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12 pages, 2071 KB  
Article
Eudesmane-Type Sesquiterpene Glycosides from Dictamnus dasycarpus Turcz.
by Shengcai Yang, Zheng Li, Jianli Wang, Jingya Ruan, Chang Zheng, Peijian Huang, Lifeng Han, Yi Zhang and Tao Wang
Molecules 2018, 23(3), 642; https://doi.org/10.3390/molecules23030642 - 13 Mar 2018
Cited by 13 | Viewed by 5793
Abstract
Eudesmane-type sesquiterpenes have been reported to exhibit varieties of biological activities. During the process of investigating this kind of natural product from the root bark of Dictamnus dasycarpus Turcz., 13 eudesmane-type sesquiterpene glycosides including six new isolates, named as dictameudesmnosides A1 ( [...] Read more.
Eudesmane-type sesquiterpenes have been reported to exhibit varieties of biological activities. During the process of investigating this kind of natural product from the root bark of Dictamnus dasycarpus Turcz., 13 eudesmane-type sesquiterpene glycosides including six new isolates, named as dictameudesmnosides A1 (1), A2 (2), B (3), C (4), D (5), and E (6), together with seven known ones (713), were obtained. Herein, their structures were determined by the analysis of physical data, spectroscopic analysis, and chemical methods. The existence of α-configuration glucose units in their structures (15, 8) is not very common in natural glycosidic components. Meanwhile, compounds 35, 7, and 913 displayed TG accumulation inhibitory effects on HepG2 cells. Full article
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15 pages, 3723 KB  
Review
Synthesis of O-Amino Sugars and Nucleosides
by Na Chen and Juan Xie
Molecules 2018, 23(3), 641; https://doi.org/10.3390/molecules23030641 - 12 Mar 2018
Cited by 5 | Viewed by 9942
Abstract
Nucleic acids and carbohydrates are essential biomolecules involved in numerous biological and pathological processes. Development of multifunctional building blocks based on nucleosides and sugars is in high demand for the generation of novel oligonucleotide mimics and glycoconjugates for biomedical applications. Recently, aminooxyl-functionalized compounds [...] Read more.
Nucleic acids and carbohydrates are essential biomolecules involved in numerous biological and pathological processes. Development of multifunctional building blocks based on nucleosides and sugars is in high demand for the generation of novel oligonucleotide mimics and glycoconjugates for biomedical applications. Recently, aminooxyl-functionalized compounds have attracted increasing research interest because of their easy derivatization through oxime ligation or N-oxyamide formation reactions. Various biological applications have been reported for O-amino carbohydrate- and nucleoside-derived compounds. Here, we report our efforts in the design and synthesis of glyco-, glycosyl, nucleoside- and nucleo-aminooxy acid derivatives from readily available sugars and amino acids, and their use for the generation of N-oxyamide-linked oligosaccharides, glycopeptides, glycolipids, oligonucleosides and nucleopeptides as novel glycoconjugates or oligonucleotide mimics. Delicate and key points in the synthesis will be emphasized. Full article
(This article belongs to the Special Issue Glycomimetics: Design, Synthesis and Therapeutic Applications)
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10 pages, 1132 KB  
Article
An Efficient Chemoenzymatic Approach towards the Synthesis of Rugulactone
by Theodore Tyrikos-Ergas, Vasileios Giannopoulos and Ioulia Smonou
Molecules 2018, 23(3), 640; https://doi.org/10.3390/molecules23030640 - 12 Mar 2018
Cited by 4 | Viewed by 3911
Abstract
Rugulactone is a natural product isolated from the plant Cryptocarya rugulosa. It has shown very important biological activity as an inhibitor of the nuclear factor κB (NF-κB) activation pathway. A new chemoenzymatic approach towards the synthesis of rugulactone is presented here. The [...] Read more.
Rugulactone is a natural product isolated from the plant Cryptocarya rugulosa. It has shown very important biological activity as an inhibitor of the nuclear factor κB (NF-κB) activation pathway. A new chemoenzymatic approach towards the synthesis of rugulactone is presented here. The chirality, induced to the key intermediate by a stereoselective enzymatic reduction utilizing NADPH-dependent ketoreductase, is described in detail. Full article
(This article belongs to the Section Bioorganic Chemistry)
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7 pages, 1315 KB  
Communication
Prenylated Polyphenols from Broussonetia kazinoki as Inhibitors of Nitric Oxide Production
by Da Yeon Lee, Hwa Jin Lee and Jae-Ha Ryu
Molecules 2018, 23(3), 639; https://doi.org/10.3390/molecules23030639 - 12 Mar 2018
Cited by 10 | Viewed by 4628
Abstract
Excessive nitric oxide (NO) production by macrophages has been involved in inflammatory diseases. Seven polyphenols (17) were isolated from Broussonetia kazinoki (B. kazinoki) and investigated as potential inhibitors of NO overproduction in lipopolysaccharide (LPS)-activated RAW 264.7 cells. Among them, [...] Read more.
Excessive nitric oxide (NO) production by macrophages has been involved in inflammatory diseases. Seven polyphenols (17) were isolated from Broussonetia kazinoki (B. kazinoki) and investigated as potential inhibitors of NO overproduction in lipopolysaccharide (LPS)-activated RAW 264.7 cells. Among them, four prenylated polyphenols (24 and 6) with a catechol moiety efficiently suppressed the LPS-induced high level of NO with IC50 values of less than 6 µM. The compounds 24 and 6 also attenuated protein and mRNA levels of inducible nitric oxide synthase (iNOS). Moreover, they suppressed the nuclear factor κB (NF-κB) activity by inhibiting the degradation of inhibitory-κB-α (I-κB-α) and the translocation of NF-κB into the nucleus in LPS-activated macrophages. Taken together, these findings suggest that polyphenols from B. kazinoki might be beneficial for treatment of inflammatory diseases. Full article
(This article belongs to the Collection Bioactive Compounds)
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24 pages, 1791 KB  
Review
Recent Advances in Zirconium-89 Chelator Development
by Nikunj B. Bhatt, Darpan N. Pandya and Thaddeus J. Wadas
Molecules 2018, 23(3), 638; https://doi.org/10.3390/molecules23030638 - 12 Mar 2018
Cited by 101 | Viewed by 9962
Abstract
The interest in zirconium-89 (89Zr) as a positron-emitting radionuclide has grown considerably over the last decade due to its standardized production, long half-life of 78.2 h, favorable decay characteristics for positron emission tomography (PET) imaging and its successful use in a [...] Read more.
The interest in zirconium-89 (89Zr) as a positron-emitting radionuclide has grown considerably over the last decade due to its standardized production, long half-life of 78.2 h, favorable decay characteristics for positron emission tomography (PET) imaging and its successful use in a variety of clinical and preclinical applications. However, to be utilized effectively in PET applications it must be stably bound to a targeting ligand, and the most successfully used 89Zr chelator is desferrioxamine B (DFO), which is commercially available as the iron chelator Desferal®. Despite the prevalence of DFO in 89Zr-immuno-PET applications, the development of new ligands for this radiometal is an active area of research. This review focuses on recent advances in zirconium-89 chelation chemistry and will highlight the rapidly expanding ligand classes that are under investigation as DFO alternatives. Full article
(This article belongs to the Special Issue Current Aspects of Radiopharmaceutical Chemistry)
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16 pages, 2855 KB  
Article
Discovery of Oxime Ethers as Hepatitis B Virus (HBV) Inhibitors by Docking, Screening and In Vitro Investigation
by Jie Tan, Min Zhou, Xinhua Cui, Zhuocai Wei and Wanxing Wei
Molecules 2018, 23(3), 637; https://doi.org/10.3390/molecules23030637 - 12 Mar 2018
Cited by 9 | Viewed by 4574
Abstract
A series of oxime ethers with C6-C4 fragment was designed and virtually bioactively screened by docking with a target, then provided by a Friedel–Crafts reaction, esterification (or amidation), and oximation from p-substituted phenyl derivatives (Methylbenzene, Methoxybenzene, Chlorobenzene). Anti-hepatitis B [...] Read more.
A series of oxime ethers with C6-C4 fragment was designed and virtually bioactively screened by docking with a target, then provided by a Friedel–Crafts reaction, esterification (or amidation), and oximation from p-substituted phenyl derivatives (Methylbenzene, Methoxybenzene, Chlorobenzene). Anti-hepatitis B virus (HBV) activities of all synthesized compounds were evaluated with HepG2.2.15 cells in vitro. Results showed that most of compounds exhibited low cytotoxicity on HepG2.2.15 cells and significant inhibition on the secretion of HBsAg and HBeAg. Among them, compound 5c-1 showed the most potent activity on inhibiting HBsAg secretion (IC50 = 39.93 μM, SI = 28.51). Results of the bioactive screening showed that stronger the compounds bound to target human leukocyte antigen A protein in docking, the more active they were in anti-HBV activities in vitro. Full article
(This article belongs to the Section Medicinal Chemistry)
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12 pages, 2443 KB  
Article
Lung Cancer Chemopreventive Activity of Patulin Isolated from Penicillium vulpinum
by Aymeric Monteillier, Pierre-Marie Allard, Katia Gindro, Jean-Luc Wolfender and Muriel Cuendet
Molecules 2018, 23(3), 636; https://doi.org/10.3390/molecules23030636 - 12 Mar 2018
Cited by 12 | Viewed by 5256
Abstract
Lung cancer is the most lethal form of cancer in the world. Its development often involves an overactivation of the nuclear factor kappa B (NF-κB) pathway, leading to increased cell proliferation, survival, mobility, and a decrease in apoptosis. Therefore, NF-κB inhibitors are actively [...] Read more.
Lung cancer is the most lethal form of cancer in the world. Its development often involves an overactivation of the nuclear factor kappa B (NF-κB) pathway, leading to increased cell proliferation, survival, mobility, and a decrease in apoptosis. Therefore, NF-κB inhibitors are actively sought after for both cancer chemoprevention and therapy, and fungi represent an interesting unexplored reservoir for such molecules. The aim of the present work was to find naturally occurring lung cancer chemopreventive compounds by investigating the metabolites of Penicillium vulpinum, a fungus that grows naturally on dung. Penicillium vulpinum was cultivated in Potato Dextrose Broth and extracted with ethyl acetate. Bioassay-guided fractionation of this extract was performed by measuring NF-κB activity using a HEK293 cell line transfected with an NF-κB-driven luciferase reporter gene. The mycotoxin patulin was identified as a nanomolar inhibitor of TNF-α-induced NF-κB activity. Immunocytochemistry and Western blot analyses revealed that its mechanism of action involved an inhibition of p65 nuclear translocation and was independent from the NF-κB inhibitor α (IκBα) degradation process. Enhancing its interest in lung cancer chemoprevention, patulin also exhibited antiproliferative, proapoptotic, and antimigration effects on human lung adenocarcinoma cells through inhibition of the Wnt pathway. Full article
(This article belongs to the Special Issue Plant Derived Natural Products and Age Related Diseases)
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11 pages, 3328 KB  
Concept Paper
Development of Dipicolylamine-Modified Cyclodextrins for the Design of Selective Guest-Responsive Receptors for ATP
by Tatsuru Yamada, Shoji Fujiwara, Kyohhei Fujita, Yuji Tsuchido, Takeshi Hashimoto and Takashi Hayashita
Molecules 2018, 23(3), 635; https://doi.org/10.3390/molecules23030635 - 12 Mar 2018
Cited by 17 | Viewed by 6592
Abstract
The construction of supramolecular recognition systems based on specific host–guest interactions has been studied in order to design selective chemical sensors. In this study, guest-responsive receptors for ATP have been designed with cyclodextrins (CyDs) as a basic prototype of the turn-on type fluorescent [...] Read more.
The construction of supramolecular recognition systems based on specific host–guest interactions has been studied in order to design selective chemical sensors. In this study, guest-responsive receptors for ATP have been designed with cyclodextrins (CyDs) as a basic prototype of the turn-on type fluorescent indicator. We synthesized dipicolylamine (DPA)-modified CyD–Cu2+ complexes (Cu·1α, Cu·1β, and Cu·1γ), and evaluated their recognition capabilities toward phosphoric acid derivatives in water. The UV-Vis absorption and fluorescence spectra revealed that Cu·1β selectively recognized ATP over other organic and inorganic phosphates, and that β-CyD had the most suitable cavity size for complexation with ATP. The 1D and 2D NMR analyses suggested that the ATP recognition was based on the host–guest interaction between the adenine moiety of ATP and the CyD cavity, as well as the recognition of phosphoric moieties by the Cu2+–DPA complex site. The specific interactions between the CyD cavity and the nucleobases enabled us to distinguish ATP from other nucleoside triphosphates, such as guanosine triphosphate (GTP), uridine triphosphate (UTP), and cytidine triphosphate (CTP). This study clarified the basic mechanisms of molecular recognition by modified CyDs, and suggested the potential for further application of CyDs in the design of highly selective supramolecular recognition systems for certain molecular targets in water. Full article
(This article belongs to the Special Issue Cyclodextrin Chemistry 2018)
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19 pages, 3953 KB  
Article
Increasing Polarity in Tacrine and Huprine Derivatives: Potent Anticholinesterase Agents for the Treatment of Myasthenia Gravis
by Carles Galdeano, Nicolas Coquelle, Monika Cieslikiewicz-Bouet, Manuela Bartolini, Belén Pérez, M. Victòria Clos, Israel Silman, Ludovic Jean, Jacques-Philippe Colletier, Pierre-Yves Renard and Diego Muñoz-Torrero
Molecules 2018, 23(3), 634; https://doi.org/10.3390/molecules23030634 - 11 Mar 2018
Cited by 34 | Viewed by 6579
Abstract
Symptomatic treatment of myasthenia gravis is based on the use of peripherally-acting acetylcholinesterase (AChE) inhibitors that, in some cases, must be discontinued due to the occurrence of a number of side-effects. Thus, new AChE inhibitors are being developed and investigated for their potential [...] Read more.
Symptomatic treatment of myasthenia gravis is based on the use of peripherally-acting acetylcholinesterase (AChE) inhibitors that, in some cases, must be discontinued due to the occurrence of a number of side-effects. Thus, new AChE inhibitors are being developed and investigated for their potential use against this disease. Here, we have explored two alternative approaches to get access to peripherally-acting AChE inhibitors as new agents against myasthenia gravis, by structural modification of the brain permeable anti-Alzheimer AChE inhibitors tacrine, 6-chlorotacrine, and huprine Y. Both quaternization upon methylation of the quinoline nitrogen atom, and tethering of a triazole ring, with, in some cases, the additional incorporation of a polyphenol-like moiety, result in more polar compounds with higher inhibitory activity against human AChE (up to 190-fold) and butyrylcholinesterase (up to 40-fold) than pyridostigmine, the standard drug for symptomatic treatment of myasthenia gravis. The novel compounds are furthermore devoid of brain permeability, thereby emerging as interesting leads against myasthenia gravis. Full article
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