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One-pot synthesis of γ-lactams from ketoaziridines. Org Biomol Chem 2023; 21:9128-9132. [PMID: 37966723 DOI: 10.1039/d3ob01568h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2023]
Abstract
The remarkable biological activities of γ-lactams have stimulated the search for efficient synthetic methods to achieve these scaffolds. In this work, we have developed a simple one-pot diastereoselective synthesis of new γ-lactams from ketoaziridines with moderate to good yields via the Horner-Wadsworth-Emmons reaction, followed by an intramolecular ester-aziridine cyclization and its opening in situ. Preliminary efforts towards an enantioselective version of this method are also reported.
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2
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Copper-Catalyzed Synthesis of Pyrrolo[1,2- c]quinazolines and Pyrrolo[2,1- a]isoquinolines and Antiplasmodial Evaluation. J Org Chem 2023. [PMID: 37272775 DOI: 10.1021/acs.joc.3c00616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Reactions involving C(sp3)-H bonds of azaarenes have been widely studied in recent years as they allow direct functionalization of these N-heterocycles without the use of harsh reaction conditions. In this work, we describe the C(sp3)-H functionalization of 4-methylquinazolines and 1-benzylisoquinolines, employing α-substituted β-nitrostyrenes catalyzed by inexpensive copper acetate. Under the optimized condition, 21 pyrrolo[1,2-c]quinazolines, as well as an imidazo[1,2-c]quinazoline and 4 pyrrolo[2,1-a]isoquinolines, were obtained in moderate to good yields. Furthermore, the biological activity of the pyrrolo[1,2-c]quinazolines was evaluated against Plasmodium falciparum, and promising results were obtained.
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3
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Rh(III)-Catalyzed C-2 Alkylation of Indoles followed by a Post-Synthetic Modification via the Ugi Reaction. ChemistryOpen 2023; 12:e202300070. [PMID: 37287423 DOI: 10.1002/open.202300070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 05/09/2023] [Indexed: 06/09/2023] Open
Abstract
Indole derivatives substituted at the C-2 position have shown important biological activities. Due to these properties, several methods have been described for the preparation of structurally diverse indoles. In this work, we have synthesized highly functionalized indole derivatives via Rh(III)-catalyzed C-2 alkylation with nitroolefins. Under the optimized condition, 23 examples were prepared with 39-80 % yield. Moreover, the nitro compounds were reduced and submitted to the Ugi four-component reaction, furnishing a series of new indole-peptidomimetics in moderate to good overall yields.
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4
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Greener organic synthetic methods: Sonochemistry and heterogeneous catalysis promoted multicomponent reactions. ULTRASONICS SONOCHEMISTRY 2021; 78:105704. [PMID: 34454180 PMCID: PMC8406036 DOI: 10.1016/j.ultsonch.2021.105704] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 07/24/2021] [Accepted: 07/29/2021] [Indexed: 06/06/2023]
Abstract
Ultrasound is an essential technique to improve organic synthesis from the point of view of green chemistry, as it can promote better yields and selectivities, in addition to shorter reaction times when compared to the conventional methods. Heterogeneous catalysis is another pillar of sustainable chemistry being the recycling and reuse of the catalysts one of its great advantage. In the other hand, multicomponent reactions provide the synthesis of structurally diverse compounds, in a one-pot fashion, without isolation and purification of intermediates. Thus, the combination of these protocols has proved to be a powerful tool to obtain biologically active organic compounds with lower costs, time and energy consumption. Herein, we provide a comprehensive overview of advances on methods of organic synthesis that have been reported over the past ten years with focus on ultrasound-assisted multicomponent reactions under heterogeneous catalysis. In particular, we present pharmacologically important N- and O-heterocyclic compounds, considering their synthetic methods using green solvents, and catalyst recycling.
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5
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USY-zeolite catalyzed synthesis of 1,4-dihydropyridines under microwave irradiation: structure and recycling of the catalyst. J Mol Struct 2021. [DOI: 10.1016/j.molstruc.2020.129430] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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6
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Synthesis of N-alkylated lipopeptides and their application as organocatalysts in asymmetric Michael addition in aqueous environments. NEW J CHEM 2021. [DOI: 10.1039/d1nj01112j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A library of N-alkylated lipopeptide organocatalysts were synthesized through an isocyanide-based multicomponent reaction.
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7
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Green Approach for Visible-Light-Induced Direct Functionalization of 2-Methylquinolines. J Org Chem 2020; 85:11663-11678. [PMID: 32852210 DOI: 10.1021/acs.joc.0c01203] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A transition metal- and oxidant-free visible light-photoinduced protocol for direct functionalization of 2-methylquinolines has been developed. This protocol enabled the C-H functionalization of substituted 2-methylquinolines with diacetyl or ethyl pyruvate, under environmentally friendly conditions. A mechanistic investigation based on density functional theory (DFT) calculations provided details about the origins of reactivity and selectivity.
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8
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Copper-Catalyzed One-Pot Synthesis of 3-( N
-Heteroarenyl)acrylonitriles through Radical Conjugated Addition of β-Nitrostyrene to Methylazaarenes. European J Org Chem 2020. [DOI: 10.1002/ejoc.202000673] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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9
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Green asymmetric synthesis of epoxypeptidomimetics and evaluation as human cathepsin K inhibitors. Bioorg Med Chem 2020; 28:115597. [DOI: 10.1016/j.bmc.2020.115597] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 05/29/2020] [Accepted: 06/08/2020] [Indexed: 10/24/2022]
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10
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Photoredox Catalysis toward 2-Sulfenylindole Synthesis through a Radical Cascade Process. Org Lett 2020; 22:4266-4271. [DOI: 10.1021/acs.orglett.0c01297] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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11
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C(
sp
3
)−C(
sp
3
) Cross‐Coupling of Alkyl Bromides and Ethers Mediated by Metal and Visible Light Photoredox Catalysis. Adv Synth Catal 2020. [DOI: 10.1002/adsc.202000167] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Abstract
Multicomponent reactions (MCRs) undoubtedly correspond to one of the synthetic strategies that best fit the new demands of chemistry for presenting high atom economy and enabling molecular diversity. However, many challenges still exist when products possessing stereogenic centres are formed. The field of asymmetric catalytic reactions has achieved significant progress in recent decades; new applications for chiral ligands and catalysts have been demonstrated and new catalysts have been specifically designed for challenging chemical conversions. In this sense, highly efficient approaches for classic multicomponent reactions such as the Ugi reaction and a number of new asymmetric MCRs have been described. In this review we discuss the recent developments that enable catalytic enantioselective MCRs including the proposed mechanistic pathways.
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Green One-Pot Asymmetric Synthesis of Peptidomimetics via Sequential Organocatalyzed Aziridination and Passerini Multicomponent Reaction. SYNTHESIS-STUTTGART 2019. [DOI: 10.1055/s-0039-1690774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Peptidomimetics containing an aziridine moiety have been reported as potent cysteine protease inhibitors. In this sense, the development of stereoselective and sustainable synthetic strategies to obtain three-membered N-heterocyclic compounds has gained importance in the last decades. In this work, an efficient method was designed to achieve highly functionalized aziridine peptidomimetics via a sequential reaction, which involves the organocatalytic aziridination of α,β-unsaturated aldehydes followed by the Passerini multicomponent reaction in an environmentally friendly solvent mixture (ethanol: water).
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Organocatalytic asymmetric vinylogous 1,4-addition of α,α-Dicyanoolefins to chalcones under a bio-based reaction media: Discovery of new Michael adducts with antiplasmodial activity. Tetrahedron 2019. [DOI: 10.1016/j.tet.2019.05.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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16
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Synthesis of (Z)-β-halo α,β-unsaturated carbonyl systems via the combination of halotrimethylsilane and tetrafluoroboric acid. Org Biomol Chem 2019; 17:519-526. [PMID: 30569046 DOI: 10.1039/c8ob02110d] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A convenient and broadly applicable method for the hydrohalogenation of ynones is described, by the combination of halotrimethylsilanes and tetrafluoroboric acid. Practically, one equivalent of HX (Brønsted acid) and BF3 (Lewis acid) is smoothly generated, which activates the carbonyl compounds. Through this protocol, 42 examples of (Z)-β-halovinyl carbonyl compounds (Cl, Br and I) were obtained, in good yields and high stereoselectivity having 2-MeTHF as a solvent.
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17
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A stereoselective sequential organocascade and multicomponent approach for the preparation of tetrahydropyridines and chimeric derivatives. Chem Commun (Camb) 2019; 55:286-289. [DOI: 10.1039/c8cc06871b] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
A stereoselective multicomponent approach leading to a novel class of pentasubstituted tetrahydropyridines is described.
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18
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Step economy strategy for the synthesis of amphoteric aminoaldehydes, key intermediates for reduced hydantoins. PURE APPL CHEM 2018. [DOI: 10.1515/pac-2017-0705] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Despite of the orthogonal reactivity of the N–H aziridines aldehyde, these compounds exist as an equilibrium of three different forms – whereas the dimeric one is mostly observed in a variety of solvents. In this work, we have developed an alternative protocol for the aminoaldehyde dimers synthesis in two steps starting with an organocatalyzed aziridination between α,β-unsaturated aldehydes and a protected amine to afford known isolable and stable N-protected aziridine aldehydes. After Boc-deprotection, dimeric species were immediately formed from monomeric N–H aziridine aldehydes. From this building-block new reduced hydantoins were prepared via [3+2]-annulation with isocyanates.
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Angelica Lactones: From Biomass-Derived Platform Chemicals to Value-Added Products. CHEMSUSCHEM 2018; 11:25-47. [PMID: 28834397 DOI: 10.1002/cssc.201701469] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Indexed: 06/07/2023]
Abstract
The upgrading of biomass-derived compounds has arisen in recent years as a very promising research field in both academia and industry. In this sense, a lot of new processes and products have been developed, often involving levulinic acid as a starting material or intermediate. In the last few years, though, other scaffolds have been receiving growing attention, especially, angelica lactones. Considering these facts and the emergent applications of said molecules, in this review we will discuss their preparation and applications; the use of these frameworks as starting materials in organic synthesis to produce potential bioactive compounds will be covered, as will their use as a foundation to highly regarded compounds such as liquid alkanes with prospective use as fuels and polymers.
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Intramolecular radical cyclization approach to access highly substituted indolines and 2,3-dihydrobenzofurans under visible-light. RSC Adv 2018; 8:12879-12886. [PMID: 35541239 PMCID: PMC9079632 DOI: 10.1039/c8ra01787e] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 03/21/2018] [Indexed: 11/29/2022] Open
Abstract
The combination of visible-light and tris(trimethylsilyl)silane promoting intramolecular reductive cyclization protocol for the synthesis of functionalized indolines and 2,3-dihydrobenzofurans has been developed. The transformations occur in the absence of transition metal and additional photocatalyst. In addition, quantum yield (Φ) was determined and electron paramagnetic resonance spectroscopy was performed to better understand the reaction pathway. The combination of visible-light and tris(trimethylsilyl)silane promoting intramolecular reductive cyclization protocol for the synthesis of functionalized indolines and 2,3-dihydrobenzofurans has been developed.![]()
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Asymmetric synthesis of new γ-butenolides via organocatalyzed epoxidation of chalcones. Org Biomol Chem 2017; 15:6098-6103. [DOI: 10.1039/c7ob00165g] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A greener three-step sequence, with only one single chromatographic purification, afforded γ-butenolides in moderate overall yield and high enantiomeric excess.
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22
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9-Benzoyl 9-deazaguanines as potent xanthine oxidase inhibitors. Bioorg Med Chem 2015; 24:226-31. [PMID: 26712096 DOI: 10.1016/j.bmc.2015.12.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 11/23/2015] [Accepted: 12/05/2015] [Indexed: 11/28/2022]
Abstract
A novel potent xanthine oxidase inhibitor, 3-nitrobenzoyl 9-deazaguanine (LSPN451), was selected from a series of 10 synthetic derivatives. The enzymatic assays were carried out using an on-flow bidimensional liquid chromatography (2D LC) system, which allowed the screening¸ the measurement of the kinetic inhibition constant and the characterization of the inhibition mode. This compound showed a non-competitive inhibition mechanism with more affinity for the enzyme-substrate complex than for the free enzyme, and inhibition constant of 55.1±9.80 nM, about thirty times more potent than allopurinol. Further details of synthesis and enzymatic studies are presented herein.
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23
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Highly Stereoselective Synthesis of Natural-Product-Like Hybrids by an Organocatalytic/Multicomponent Reaction Sequence. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201412074] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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24
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Highly stereoselective synthesis of natural-product-like hybrids by an organocatalytic/multicomponent reaction sequence. Angew Chem Int Ed Engl 2015; 54:7621-5. [PMID: 25967546 DOI: 10.1002/anie.201412074] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 03/19/2015] [Indexed: 01/29/2023]
Abstract
In an endeavor to provide an efficient route to natural product hybrids, described herein is an efficient, highly stereoselective, one-pot process comprising an organocatalytic conjugate addition of 1,3-dicarbonyls to α,β-unsaturated aldehydes followed by an intramolecular isocyanide-based multicomponent reaction. This approach enables the rapid assembly of complex natural product hybrids including up to four different molecular fragments, such as hydroquinolinone, chromene, piperidine, peptide, lipid, and glycoside moieties. The strategy combines the stereocontrol of organocatalysis with the diversity-generating character of multicomponent reactions, thus leading to structurally unique peptidomimetics integrating heterocyclic, lipidic, and sugar moieties.
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25
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Highly Efficient and Magnetically Recoverable Niobium Nanocatalyst for the Multicomponent Biginelli Reaction. ChemCatChem 2014. [DOI: 10.1002/cctc.201402689] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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26
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Evaluation of 2',4'-dihydroxy-3,4,5-trimethoxychalcone as antimitotic agent that induces mitotic catastrophe in MCF-7 breast cancer cells. Toxicol Lett 2014; 229:393-401. [PMID: 24968064 DOI: 10.1016/j.toxlet.2014.06.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Revised: 06/09/2014] [Accepted: 06/10/2014] [Indexed: 12/28/2022]
Abstract
We previously reported the synthesis and the anti-proliferative action of 2',4'-dihydroxy-3,4,5-trimethoxychalcone. Here we reported its mechanism of action on MCF-7 cells. The compound induced aberrant spindles, and arrested cells at metaphase/anaphase boundary with accumulation of checkpoint proteins Mad2, Bub1 and BubR1. Live cell imaging revealed that the compound sustained a prolonged mitotic arrest, followed by massive cell death. The results indicate that 2',4'-dihydroxy-3,4,5-trimethoxychalcone exerts its anti-proliferative activity by affecting microtubules and causing mitotic catastrophe, and thus has the potential for antitumor activity.
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Cuticular Hydrocarbons of Heterotermes tenuis (Isoptera: Rhinotermitidae): Analyses and Electrophysiological Studies. ACTA ACUST UNITED AC 2014; 59:135-9. [PMID: 15018067 DOI: 10.1515/znc-2004-1-226] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Termites have become an important pest of Eucalyptus and Pinus reforestations, sugarcane and other cultures. An alternative for the control of this pest would be the use of attractive traps that take in account the social behavior of these insects. Diverse factors are important for the insects in the localization of the habitat and the choice of the food and specific odors can facilitate this. Studies referring to Heterotermes tenuis (Isoptera: Rhinotermitidae) are scarce. The objective of this work was to analyze the tergal cuticular extract of H. tenuis and determine the selectivity and sensitivity of its antennae to the components of this extract by electroantennography (EAG). The composition of the cuticular extract was determined by GC-MS analysis. The hydrocarbons found were restricted to linear alkanes, being most abundant C24 to C27 that comprises ca. 65% of the total. Olefins were not detected. EAG and behavioral test responses to the cuticular hydrocarbons were greater and significantly different from the control and the high selectivity of the antennae to the extract indicates its potential as chemical messenger. Cuticular hydrocarbons mixture is species-specific and can be used to identify a given taxon without the diagnostic castes, soldiers or imagoes. Difference in the composition appears to relate with the type of habitat of specie.
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An efficient one-pot strategy for the highly regioselective metal-free synthesis of 1,4-disubstituted-1,2,3-triazoles. Chem Commun (Camb) 2014; 50:11926-9. [DOI: 10.1039/c4cc04678a] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
A simple and efficient metal-free methodology for the regioselective synthesis of 1,4-disubstituted-1,2,3-triazoles by applying a novel inverse electron-demand-1,3-dipolar cycloaddition approach has been developed.
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29
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Microwave-Assisted Synthesis ofN-Heterocycles and Their Evaluation Using an Acetylcholinesterase Immobilized Capillary Reactor. J BRAZIL CHEM SOC 2014. [DOI: 10.5935/0103-5053.20140056] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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30
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Multicomponent Combinatorial Development and Conformational Analysis of Prolyl Peptide–Peptoid Hybrid Catalysts: Application in the Direct Asymmetric Michael Addition. J Org Chem 2013; 78:10221-32. [DOI: 10.1021/jo401609z] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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31
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1,1-Diamino-2-nitroethylenes as excellent hydrogen bond donor organocatalysts in the Michael addition of carbon-based nucleophiles to β-nitrostyrenes. Tetrahedron 2013. [DOI: 10.1016/j.tet.2013.08.040] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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32
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An Eco-Friendly Asymmetric Organocatalytic Conjugate Addition of Malonates to α,β-Unsaturated Aldehydes: Application on the Synthesis of Chiral Indoles. European J Org Chem 2013. [DOI: 10.1002/ejoc.201300431] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Anti-tuberculosis neolignans from Piper regnellii. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2013; 20:600-604. [PMID: 23474218 DOI: 10.1016/j.phymed.2013.01.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Revised: 12/11/2012] [Accepted: 01/26/2013] [Indexed: 06/01/2023]
Abstract
The present study determined the anti-Mycobacterium tuberculosis activities of supercritical CO2 extracts, neolignans eupomatenoid-5 (1), conocarpan (4) and eupomatenoid-3 (7) and their derivatives (2, 3, 5, 6, and 8) from Piper regnellii, as well as their cytotoxicities. The supercritical CO2 extract from leaves was purified by chromatographic methods, yielding compounds (1), (4) and (7), which were identified by (1)H NMR and comparison with literature data. Anti-M. tuberculosis activity (H37Rv and clinical isolates) was evaluated using a resazurin microtiter assay plate (REMA) to determine the MIC. The cytotoxicity assay was carried out in macrophages J774G.8 by sulforhodamine B colorimetric assay. The supercritical CO2 extracts from leaves and stems, and compound (4) showed activity against M. tuberculosis (MIC 15.6 μg/ml). Compound (1) showed the best activity (MIC 1.9 μg/ml), with good SI. Compounds (7) and (8) showed low activity against M. tuberculosis H37Rv. The derivative compounds did not show increased anti-M. tuberculosis activity. This is the first report, to our knowledge, to describe neolignans from P. regnellii with activity against M. tuberculosis, and compound (1) is a potential candidate for future antituberculosis drugs.
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Basic-functionalized recyclable ionic liquid catalyst: A solvent-free approach for Michael addition of 1,3-dicarbonyl compounds to nitroalkenes under ultrasound irradiation. ULTRASONICS SONOCHEMISTRY 2013; 20:793-798. [PMID: 23218731 DOI: 10.1016/j.ultsonch.2012.11.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Revised: 10/22/2012] [Accepted: 11/03/2012] [Indexed: 06/01/2023]
Abstract
A task-specific ionic liquid (TSIL) has been introduced as a recyclable catalyst in Michael addition. A series of nitroalkenes and various C-based nucleophiles were reacted in the presence of 30mol% of recyclable basic-functionalized ionic liquid. Good to excellent yields were obtained in 30min under ultrasound irradiation.
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Multidimensional optimization of promising antitumor xanthone derivatives. Bioorg Med Chem 2013; 21:2941-59. [PMID: 23623253 DOI: 10.1016/j.bmc.2013.03.079] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Revised: 03/20/2013] [Accepted: 03/26/2013] [Indexed: 01/18/2023]
Abstract
A promising antitumor xanthone derivative was optimized following a multidimensional approach that involved the synthesis of 17 analogues, the study of their lipophilicity and solubility, and the evaluation of their growth inhibitory activity on four human tumor cell lines. A new synthetic route for the hit xanthone derivative was also developed and applied for the synthesis of its analogues. Among the used cell lines, the HL-60 showed to be in general more sensitive to the compounds tested, with the most potent compound having a GI50 of 5.1 μM, lower than the hit compound. Lipophilicity was evaluated by the partition coefficient (K(p)) of a solute between buffer and two membrane models, namely liposomes and micelles. The compounds showed a logK(p) between 3 and 5 and the two membrane models showed a good correlation (r(2)=0.916) between each other. Studies concerning relationship between solubility and structure were developed for the hit compound and 5 of its analogues.
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Acetylcholinesterase immobilized capillary reactors-tandem mass spectrometry: an on-flow tool for ligand screening. J Med Chem 2013; 56:2038-44. [PMID: 23330848 DOI: 10.1021/jm301732a] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The use of immobilized capillary enzyme reactors (ICERs) for online ligand screening has been adopted as a new technique for high-throughput screening (HTS). In this work, the selected target was the enzyme acetylcholinesterase (AChE), and the AChE-ICERs produced were used in a liquid chromatograph-tandem ion-trap mass spectrometer. The activity and kinetic parameters were evaluated by monitoring the choline's precursor ion (M + H)(+)m/z 104.0 and its ion fragment (C2H3OH) - (M + H)(+)m/z 60.0. The assay method was validated using the reference AChE inhibitors tacrine and galanthamine. Two new ligands, out of a library of 17 coumarin derivatives, were identified, and the half-maximal inhibitory concentration (IC50), inhibition constant (K(i)), and the inhibition mechanism were determined. A coumarin derivative with IC50 similar to tacrine was highlighted.
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Atividade inseticida de óleos essenciais de Pelargonium graveolens l'Herit e Lippia alba (Mill) N. E. Brown sobre Spodoptera frugiperda (J. E. Smith). QUIM NOVA 2013. [DOI: 10.1590/s0100-40422013000900020] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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39
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Iron(III) chloride catalyzed glycosylation of peracylated sugars with allyl/alkynyl alcohols. J BRAZIL CHEM SOC 2012. [DOI: 10.1590/s0103-50532012005000070] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Differentiation of five pine species cultivated in Brazil based on chemometric analysis of their volatiles identified by gas chromatography-mass spectrometry. J BRAZIL CHEM SOC 2012. [DOI: 10.1590/s0103-50532012005000042] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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41
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Electrophysiological Responses of the Naupactus bipes Beetle to Essential Oils from Piperaceae Species. Nat Prod Commun 2012. [DOI: 10.1177/1934578x1200700835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Electrophysiological responses based on electroantennographic detection (GC-EAD) and electroantennography (EAG) analysis of Naupactus bipes beetles (Germar, 1824) (Coleoptera: Curculionidae: Brachycerinae) were used to test volatile oils of Piper gaudichaudianum, P. regnellii and P. hispidum. In the EAG experiments, female and male beetles showed significant EAG response to the three volatile oils of Piper species, with the females’ responses slightly higher than the males’. The experiments with GC-EAD revealed that some terpenoids (namely, α-pinene, β-pinene, myrcene, α-copaene and germacrene) present in the leaf essential oils of the Piper species are perceptible to female and male beetles.
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Electrophysiological responses of the Naupactus bipes beetle to essential oils from Piperaceae species. Nat Prod Commun 2012; 7:1103-1106. [PMID: 22978240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023] Open
Abstract
Electrophysiological responses based on electroantennographic detection (GC-EAD) and electroantennography (EAG) analysis of Naupactus bipes beetles (Germar, 1824) (Coleoptera: Curculionidae: Brachycerinae) were used to test volatile oils of Piper gaudichaudianum, P. regnellii and P. hispidum. In the EAG experiments, female and male beetles showed significant EAG response to the three volatile oils of Piper species, with the females' responses slightly higher than the males'. The experiments with GC-EAD revealed that some terpenoids (namely, alpha-pinene, beta-pinene, myrcene, alpha-copaene and germacrene) present in the leaf essential oils of the Piper species are perceptible to female and male beetles.
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Evaluation of synthetic acridones and 4-quinolinones as potent inhibitors of cathepsins L and V. Eur J Med Chem 2012; 54:10-21. [PMID: 22591648 DOI: 10.1016/j.ejmech.2012.04.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2011] [Revised: 04/03/2012] [Accepted: 04/04/2012] [Indexed: 11/16/2022]
Abstract
Cathepsins, also known as lysosomal cysteine peptidases, are members of the papain-like peptidase family, involved in different physiological processes. In addition, cathepsins are implicated in many pathological conditions. This report describes the synthesis and evaluation of a series of N-arylanthranilic acids, acridones, and 4-quinolinones as inhibitors of cathepsins V and L. The kinetics revealed that compounds of the classes of acridones are reversible competitive inhibitors of the target enzyme with affinities in the low micromolar range. They represent promising lead candidates for the discovery of novel competitive cathepsin inhibitors with enhanced selectivity and potency. On the other hand, 4-quinolinones were noncompetitive inhibitors and N-arylanthranilic acids were uncompetitive inhibitors.
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Organocatalytic asymmetric epoxidation and tandem epoxidation/Passerini reaction under eco-friendly reaction conditions. Org Biomol Chem 2012; 10:7681-4. [DOI: 10.1039/c2ob26247a] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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Solid-phase synthesis of 2'-hydroxychalcones. Effects on cell growth inhibition, cell cycle and apoptosis of human tumor cell lines. Bioorg Med Chem 2011; 20:25-33. [PMID: 22177409 DOI: 10.1016/j.bmc.2011.11.042] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Accepted: 11/20/2011] [Indexed: 11/30/2022]
Abstract
Thirty-one 2'-hydroxychalcones were prepared via solid-phase synthesis by base-catalyzed aldol condensation of substituted 2'-hydroxyacetophenones and benzaldehydes. Chalcones were tested for their growth inhibitory activity in three human tumor cell lines (MCF-7, NCI-H460 and A375-C5) using the SRB assay. Results revealed that several of the tested compounds caused a pronounced dose-dependent growth inhibitory effect on the tumor cell lines studied in the low micromolar range. To gain further insight on the cellular mechanism of action of this class of compounds, studies of their effect on cell cycle profile as well as on induction of cellular apoptosis were also carried out. Generally, the tested chalcones interfered with the cell cycle profile and increased the percentage of apoptotic MCF-7 cells. The results here presented may help to identify new chalcone-like structures with optimized cell growth inhibitory activity which may be further tested as potential antitumor agents.
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Synthesis of a combinatorial library of amides and its evaluation against the fall armyworm, Spodoptera frugiperda. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2011; 59:4822-4827. [PMID: 21443174 DOI: 10.1021/jf104903t] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The fall armyworm Spodoptera frugiperda is a polyphagous pest that causes important damage in different regions of America and mainly affects corn crops in both tropical and subtropical areas. Currently, control relies on both transgenic plants and/or chemical pesticides. In this work we describe the preparation of an indexed combinatorial library of amides and its toxic effect by contact against S. frugiperda . (E)-1-(1-Piperidinyl)-3-[4-(trifluoromethoxy)phenyl]-2-propen-1-one was the most active compound with an LD(50) = 0.793 μg mg(-1) of larva. This amide was also evaluated by ingestion and at the lowest concentration (1 mg kg(-1)) achieved 83.3% mortality.
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Solution Phase Synthesis of a Combinatorial Library of Chalcones and Flavones as Potent Cathepsin V Inhibitors. ACTA ACUST UNITED AC 2010; 12:687-95. [DOI: 10.1021/cc100076k] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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Effect of the synthetic coumarin, ethyl 2-oxo-2H-chromene-3-carboxylate, on activity of Crotalus durissus ruruima sPLA2 as well as on edema and platelet aggregation induced by this factor. Toxicon 2010; 55:1527-30. [PMID: 20223257 DOI: 10.1016/j.toxicon.2010.03.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2009] [Revised: 03/01/2010] [Accepted: 03/03/2010] [Indexed: 11/19/2022]
Abstract
We show that ethyl 2-oxo-2H-chromene-3-carboxylate (EOCC), a synthetic coumarin, irreversibly inhibits phospholipase A(2) (sPLA2) from Crotalus durissus ruruima venom (sPLA2r) with an IC(50) of 3.1 +/- 0.06 nmol. EOCC strongly decreased the V(max) and K(m), and it virtually abolished the enzyme activity of sPLA2r as well as sPLA2s from other sources. The edema induced by sPLA2r + EOCC was less than that induced by sPLA2r treated with p-bromophenacyl bromide, which was more efficient at neutralizing the platelet aggregation activity of native sPLA2r. Native sPLA2r induced platelet aggregation of 91.54 +/- 9.3%, and sPLA2r + EOCC induced a platelet aggregation of 18.56 +/- 6.5%. EOCC treatment also decreased the myotoxic effect of sPLA2r. Mass spectrometry showed that EOCC formed a stable complex with sPLA2r, which increased the mass of native sPLA2r from 14,299.34 Da to 14,736.22 Da. Moreover, the formation of this complex appeared to be involved in the loss of sPLA2r activity. Our results strongly suggest that EOCC can be used as a pharmacological agent against the sPLA2 in Crotalus durissus sp. venom as well as other sPLA2s.
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