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Artur M S Silva - One of the best experts on this subject based on the ideXlab platform.
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First intramolecular Diels–Alder reactions using chromone derivatives: synthesis of chromeno[3,4-b]xanthones and 2-(benzo[c]chromenyl)Chromones
New Journal of Chemistry, 2018Co-Authors: Hélio M. T. Albuquerque, Clementina M.m. Santos, José A. S. Cavaleiro, Artur M S SilvaAbstract:A series of novel (E)-2-(2-propargyloxystyryl)Chromones and (E,E)-2-[4-(2-propargyloxyphenyl)buta-1,3-dien-1-yl]Chromones were designed and synthesized via aldol condensation of 2-methylChromones with 2-propargyloxy(benzaldehyde and cinnamaldehyde), respectively. Both chromone derivatives were used as substrates in microwave-assisted intramolecular Diels–Alder reactions, affording chromeno[3,4-b]xanthones and 2-(benzo[c]chromenyl)Chromones. This is the first report involving chromone derivatives in intramolecular Diels–Alder reactions for the synthesis of new oxygen heterocycles, namely xanthone- and flavone-type compounds.
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Synthesis of Chromone-Related Pyrazole Compounds.
Molecules (Basel Switzerland), 2017Co-Authors: Clementina M.m. Santos, Vera L. M. Silva, Artur M S SilvaAbstract:Chromones, six-membered oxygen heterocycles, and pyrazoles, five-membered two-adjacent-nitrogen-containing heterocycles, represent two important classes of biologically active compounds. Certain derivatives of these scaffolds play an important role in medicinal chemistry and have been extensively used as versatile building blocks in organic synthesis. In this context, we will discuss the most relevant advances on the chemistry that involves both chromone and pyrazole rings. The methods reviewed include the synthesis of chromone-pyrazole dyads, synthesis of chromone-pyrazole-fused compounds, and Chromones as starting materials in the synthesis of 3(5)-(2-hydroxyaryl)pyrazoles, among others. This review will cover the literature on the chromone and pyrazole dual chemistry and their outcomes in the 21st century.
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Chromones a promising ring system for new anti inflammatory drugs
ChemMedChem, 2016Co-Authors: Carlos F M Silva, Diana C G A Pinto, Artur M S SilvaAbstract:The quest for safer anti-inflammatory drugs is still the focus of several medicinal chemistry programs. Chromones (4H-chromen-4-ones) are a group of naturally occurring compounds ubiquitous in plants, and the chromone core has proven to be a privileged scaffold in medicinal chemistry. Herein we provide an overview of the relevance of Chromones as anti-inflammatory agents, specifically as inhibitors of cyclooxygenase (COX), 5-lipoxygenase (5-LOX), interleukin-5 (IL-5), and nitric oxide (.NO) production. Numerous structure–activity relationships and mechanisms of action are discussed. This review is therefore intended to provide a foundation for the design and synthesis of novel chromone-based compound libraries for further development into safer and more efficient anti-inflammatory agents.
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actions of bisnucleophiles on e 3 3 2 hydroxyaryl 3 oxoprop 1 en 1 yl Chromones versatile transformations into oxygen and nitrogen containing heterocycles
Synlett, 2015Co-Authors: Ridha Hassaine, Oualid Talhi, Okkacha Bensaid, Khaldoun Bachari, Nadia Taibi, Artur M S SilvaAbstract:The transformations of ( E )-3-[3-(2-hydroxyaryl)-3-oxoprop-1-en-1-yl]Chromones in the presence of methylhydrazine and aromatic bisnucleophiles are described. The reactions generally lead to chromone ring transformation via pyrone ring-opening and heterocyclization to give novel diazoles and ( Z )-3-aminomethylenechromanones, respectively. Piperazine catalyzes chromanone ring closure of the starting substrate to afford chromone–chromanone dyads.
Hao-fu Dai - One of the best experts on this subject based on the ideXlab platform.
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2-(2-Phenylethyl)chromone derivatives: Promising α-glucosidase inhibitors in agarwood from Aquilaria filaria.
Phytochemistry, 2020Co-Authors: Jing-zhe Yuan, Hao Wang, Wen-li Mei, Li Yang, Man-man Zhu, Wei Yanmei, Wen-xing Long, Hao-fu DaiAbstract:Abstract Twelve undescribed 2-(2-phenylethyl)chromone derivatives, including one pair of enantiomers, together with eleven known ones, were isolated from the EtOAc extract of agarwood originating from Aquilaria filaria. All structures were elucidated by spectroscopic (NMR, UV, IR, MS) methods and compared with reported data in literatures. Twenty-one compounds were assessed for α-glucosidase inhibitory activity, which showed inhibition of α-glucosidase with IC50 values ranging between 7.8 ± 0.3 to 137.7 ± 3.0 μM (Acarbose, 743.4 ± 3.3 μM; Genistein, 8.3 ± 0.1 μM). Our results expanded the structural diversity of 2-(2-phenylethyl)Chromones from agarwood, and revealed the potential of 2-(2-phenylethyl)Chromones as α-glucosidase inhibitors.
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LC-MS guided identification of dimeric 2-(2-phenylethyl)Chromones and sesquiterpene-2-(2-phenylethyl)chromone conjugates from agarwood of Aquilaria crassna and their cytotoxicity
Fitoterapia, 2019Co-Authors: Lulu Xia, Hao Wang, Wen-li Mei, Caihong Cai, Li Yang, Hui-qin Chen, Bei Jiang, Yi-ling Yang, Hao-fu DaiAbstract:Abstract Four previously unreported dimeric 2-(2-phenylethyl)Chromones (1–4a) and three unprecedented sesquiterpene-2-(2-phenylethyl)chromone conjugates (5–7), comprising a sesquiterpenoid and a 5,6,7,8-tetrahydroxy-2-(2-phenylethyl)-5,6,7,8 -tetrahydro-4H-chromone moiety, as well as three known dimeric 2-(2-phenylethyl)Chromones (4b, 8a, 8b) were identified from agarwood originating from Aquilaria crassna in Cambodia by LC-MS guided separation. Their structures were elucidated by extensive NMR techniques, HRESIMS and CD. All compounds were evaluated for their cytotoxicity against four human cancer cell lines. Compounds 6, 7, 8a, 8b displayed a range of cytotoxic activities with IC50 values in the rang 10.93–49.0 μM
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one new 2 2 phenylethyl chromone derivative from agarwood of aquilaria crassna in cambodia
Phytochemistry Letters, 2019Co-Authors: Lulu Xia, Hao Wang, Wen-hua Dong, Wen-li Mei, Cui-juan Gai, Caihong Cai, Li Yang, Hao-fu DaiAbstract:Abstract One new 2-(2-phenylethyl)chromone (1), three new naturally occurring 2-(2-phenylethenyl)Chromones (3–5), together with a known 2-(2-phenylethyl)chromone (2) were isolated from the EtOH extract of agarwood originating from Aquilaria crassna in Cambodia. Their structures were unambiguously elucidated by detailed spectroscopic (NMR, UV, IR, MS) analyses. All the compounds were tested for acetylcholinesterase (AChE) inhibitory activity and cytotoxicity against tumor cell lines (K562, BEL-7402, SGC-7901 and Hela). Compound 1 displayed weak AChE inhibitory activity (inhibitory ratio: 35.0 ± 2.19%) and cytotoxicity against K562 tumor cell line (IC50: 40.81 ± 0.64 μM). Along with, compound 3 showed cytotoxicity against BEL-7402 tumor cell line (IC50: 44.18 ± 0.34 μM).
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Monitoring the Chemical Profile in Agarwood Formation within One Year and Speculating on the Biosynthesis of 2-(2-Phenylethyl)Chromones
MDPI AG, 2018Co-Authors: Ge Liao, Wen-hua Dong, Wen-li Mei, Jin-ling Yang, Jun Wang, Hao-fu DaiAbstract:Agarwood is highly valued for its uses as incense, perfume, and medicine. However, systematic analyses of dynamic changes of secondary metabolites during the process of agarwood formation have not yet been reported. In this study, agarwood was produced by transfusing the agarwood inducer into the trunk of Aquilaria sinensis, and changing patterns of chemical constituents, especially 2-(2-phenylethyl)Chromones (PECs), in wood samples collected from the 1st to 12th month, were analyzed by GC-EI-MS and UPLC-ESI-MS/MS methods. Aromatic compounds, steroids, fatty acids/esters, sesquiterpenoids, and PECs were detected by GC-MS, in which PECs were the major constituents. Following this, UPLC-MS was used for further comprehensive analysis of PECs, from which we found that 2-(2-phenylethyl)Chromones of flindersia type (FTPECs) were the most abundant, while PECs with epoxidated chromone moiety were detected with limited numbers and relatively low content. Speculation on the formation of major FTPECs was fully elucidated in our context. The key step of FTPECs biosynthesis is possibly catalyzed by type III polyketide synthases (PKSs) which condensate dihydro-cinnamoyl-CoA analogues and malonyl-CoA with 2-hydroxy-benzoyl-CoA to produce 2-(2-phenyethyl)chromone scaffold, or with 2,5-dihydroxybenzoyl-CoA to form FTPECS with 6-hydroxy group, which may serve as precursors for further reactions catalyzed by hydroxylase or O-methyltransferase (OMT) to produce FTPECs with diverse substitution patterns. It is the first report that systematically analyzed dynamic changes of secondary metabolites during the process of agarwood formation and fully discussed the biosynthetic pathway of PECs
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2-(2-phenylethyl)chromone derivatives from Chinese agarwood induced by artificial holing.
Fitoterapia, 2014Co-Authors: Caihong Cai, Hao Wang, Zhi-kai Guo, Wen-hua Dong, Wen-li Mei, Hao-fu DaiAbstract:Abstract Three new 2-(2-phenylethyl)chromone derivatives ( 1 – 3 ), together with thirteen known ones ( 4 – 16 ), were isolated from the EtOAc extract of Chinese agarwood induced by artificial holing, originating from Aquilaria sinensis (Lour.) Gilg (Thymelaeaceae). The chemical structures of the new compounds were identified by spectroscopic techniques (UV, IR, MS, 1D and 2D NMR). Compounds 1 , 6 , 15 and 16 exhibited inhibitory effects on Staphylococcus aureus , and compounds 15 and 16 showed inhibitory effects on Ralstonia solanacearum . Compounds 1 – 3 , 7 , 9 , 11 , 12 , 15 and 16 exhibited acetylcholinesterase inhibitory activity. A possible biogenetic pathway of compounds 1 – 16 was proposed to show the relationships between diepoxy-tetrahydro-2-(2-phenylethyl)Chromones, epoxy-tetrahydro-2-(2-phenylethyl) Chromones, tetrahydro-2-(2-phenylethyl)Chromones, and 2-(2-phenylethyl)Chromones of the flidersia type, the four main types of 2-(2-phenylethyl)Chromones found in agarwood, on the basis of their appearances in different stage of agarwood formation.
Fernanda Borges - One of the best experts on this subject based on the ideXlab platform.
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Chromone as a Privileged Scaffold in Drug Discovery: Recent Advances
Journal of medicinal chemistry, 2017Co-Authors: Joana Reis, Alexandra Gaspar, Nuno Milhazes, Fernanda BorgesAbstract:The use of privileged structures in drug discovery has proven to be an effective strategy, allowing the generation of innovative hits/leads and successful optimization processes. Chromone is recognized as a privileged structure and a useful template for the design of novel compounds with potential pharmacological interest, particularly in the field of neurodegenerative, inflammatory, and infectious diseases as well as diabetes and cancer. This perspective provides the reader with an update of an earlier article entitled “Chromone: A Valid Scaffold in Medicinal Chemistry” (Chem. Rev. 2014, 114, 4960−4992) and is mainly focused on Chromones of biological interest, including those isolated from natural sources. Moreover, as drug repurposing is becoming an attractive drug discovery approach, recent repurposing studies of chromone-based drugs are also reported.
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Discovery of novel A3 adenosine receptor ligands based on chromone scaffold.
Biochemical pharmacology, 2012Co-Authors: Alexandra Gaspar, Eugenio Uriarte, Joana Reis, Sonja Kachler, Silvia Paoletta, Karl-norbert Klotz, Stefano Moro, Fernanda BorgesAbstract:Abstract A project focused on the discovery of new chemical entities (NCEs) as AR ligands that incorporate a benzo-γ-pyrone [(4H)-1-benzopyran-4-one] substructure has been developed. Accordingly, two series of novel chromone carboxamides placed at positions C2 (compounds 2 – 13 ) and C3 (compounds 15 – 26 ) of the γ-pyrone ring were synthesized using chromone carboxylic acids (compounds 1 or 14 ) as starting materials. From this study and on the basis of the obtained structure–activity relationships it was concluded that the chromone carboxamide scaffold represent a novel class of AR ligands. The most remarkable Chromones were compounds 21 and 26 that present a better affinity for A 3 AR ( K i = 3680 nM and K i = 3750 nM, respectively). Receptor-driven molecular modeling studies provide information on the binding/selectivity data of the chromone. The data so far acquired are instrumental for future optimization of chromone carboxamide as a selective A 3 AR antagonist.
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accelerating lead optimization of chromone carboxamide scaffold throughout microwave assisted organic synthesis
Tetrahedron Letters, 2011Co-Authors: Fernando Cagide, Alexandra Gaspar, Joana Reis, Fernanda BorgesAbstract:Abstract Microwave irradiation offers a considerable advantage over conventional synthesis with rate enhancements and cleaner reactions. Accordingly, a new microwave-assisted method for the synthesis of functionalized Chromones was developed allowing the obtention of a library of chromone carboxamides. The method has been shown to present several advantages including operational simplicity, good performance, significant reduction in reaction time, less formation of by-products, and easier work-up.
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Chromone, a privileged scaffold for the development of monoamine oxidase inhibitors.
Journal of medicinal chemistry, 2011Co-Authors: Alexandra Gaspar, Tiago H. Silva, Matilde Yáñez, Dolores Viña, Franscisco Orallo, Francesco Ortuso, Eugenio Uriarte, Stefano Alcaro, Fernanda BorgesAbstract:Two series of novel chromone derivatives were synthesized and investigated for their ability to inhibit the activity of monoamine oxidase. The SAR data indicate that chromone derivatives with substituents in position 3 of γ-pyrone nucleus act preferably as MAO-B inhibitors, with IC(50) values in the nanomolar to micromolar range. Almost all chromone 3-carboxamides display selectivity toward MAO-B. Identical substitutions on position 2 of γ-pyrone nucleus result in complete loss of activity in both isoforms (Chromones 2-12 except 3 and 5). Notably, chromone (19) exhibits an MAO-B IC(50) of 63 nM, greater than 1000-fold selectivity over MAO-A, and behaves as a quasi-reversible inhibitor. Docking experiments onto the MAO binding of the most active compound highlight different interaction patterns among the isoforms A and B. The differential analysis of the solvation effects among the chromone isomers gave additional insight about the superior outline of the 3-substituted chromone derivatives.
Yunyun Liu - One of the best experts on this subject based on the ideXlab platform.
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The Domino Chromone Annulation and a Transient Halogenation-Mediated C-H Alkenylation toward 3-Vinyl Chromones.
Organic letters, 2020Co-Authors: Jie-ping Wan, Yunyun LiuAbstract:Reported in this paper is a step economical method toward the general synthesis of 3-vinyl Chromones via the reactions between readily available o-hydroxyphenyl enaminones and various alkenes. The domino C-H alkenylation and chromone annulation of the enaminones are involved, which enables the synthesis of 3-vinyl chromone products using both terminal and internal alkenes via a key process of transient C-H halogenation.
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Transition metal-free synthesis of 3-trifluoromethyl Chromones via tandem C–H trifluoromethylation and chromone annulation of enaminones
Organic Chemistry Frontiers, 2020Co-Authors: Yunyun Liu, Jie-ping WanAbstract:The tandem C–H bond trifluoromethylation and chromone annulation reactions of o-hydroxyphenyl enaminones have been realized for the practical synthesis of 3-trifluoromethyl Chromones. The reactions are performed efficiently with the promotion of K2S2O8 without using any transition metal catalyst or additive. In addition, the 3-trifluoromethyl chromone products have been successfully used for the synthesis of 3-trifluoromethyl pyrimidines by reacting with guanidine/amidine substrates.
Jie-ping Wan - One of the best experts on this subject based on the ideXlab platform.
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The Domino Chromone Annulation and a Transient Halogenation-Mediated C-H Alkenylation toward 3-Vinyl Chromones.
Organic letters, 2020Co-Authors: Jie-ping Wan, Yunyun LiuAbstract:Reported in this paper is a step economical method toward the general synthesis of 3-vinyl Chromones via the reactions between readily available o-hydroxyphenyl enaminones and various alkenes. The domino C-H alkenylation and chromone annulation of the enaminones are involved, which enables the synthesis of 3-vinyl chromone products using both terminal and internal alkenes via a key process of transient C-H halogenation.
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Transition metal-free synthesis of 3-trifluoromethyl Chromones via tandem C–H trifluoromethylation and chromone annulation of enaminones
Organic Chemistry Frontiers, 2020Co-Authors: Yunyun Liu, Jie-ping WanAbstract:The tandem C–H bond trifluoromethylation and chromone annulation reactions of o-hydroxyphenyl enaminones have been realized for the practical synthesis of 3-trifluoromethyl Chromones. The reactions are performed efficiently with the promotion of K2S2O8 without using any transition metal catalyst or additive. In addition, the 3-trifluoromethyl chromone products have been successfully used for the synthesis of 3-trifluoromethyl pyrimidines by reacting with guanidine/amidine substrates.
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Recent advances in the diversification of Chromones and flavones by direct CH bond activation or functionalization
Chinese Chemical Letters, 2020Co-Authors: Shanghui Tian, Tian Luo, Yanping Zhu, Jie-ping WanAbstract:Abstract Chromone and flavone are both central backbones of natural products and clinical medicines. Synthesis of diversely functionalized Chromones and flavones constitutes significant research contents of the modern synthetic science because abundant molecular libraries of such types are crucial in providing candidate compounds for the discovery of new pharmaceuticals and functional materials. The direct C H bond activation or functionalization on these heterocyclic backbones provides highly powerful tools for the rapid accesses to densely functionalized chromone and flavone derivatives. Considering the importance of the functionalized chromone and flavone compounds as well as the notable advances in the synthesis of such products by direct C H activation or functionalization, we review herein the research advances in the C H bond activation and functionalization reactions of chromone and flavones, in hope of showing the current states and promise of the research domain.