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Semisynthesis and Pesticidal Activities of Novel Cholesterol Ester Derivatives Containing Cinnamic Acid-like Fragments. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27238437. [PMID: 36500528 PMCID: PMC9735938 DOI: 10.3390/molecules27238437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 11/21/2022] [Accepted: 11/22/2022] [Indexed: 12/04/2022]
Abstract
Due to the extensive use of agrochemicals resulting in the emergence of pesticide resistance and ecological environment problems, the research and development of new alternatives for crop protection is highly desirable. In order to discover potent natural product-based insecticide candidates, a series of new cholesterol ester derivatives containing cinnamic acid-like fragments at the C-7 position were synthesized. Some derivatives showed potent pesticidal activities. Against Mythimna separata Walker, compounds 2a, Id, Ig, and IIg showed 2.1-2.4-fold growth-inhibitory activity of the precursor cholesterol. Against Plutella xylostella Linnaeus, compounds Ig, IIf, and IIi exhibited 1.9-2.1-fold insecticidal activity of cholesterol. These results will pave the way for the future synthesis of cholesterol-based derivatives as agrochemicals.
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Construction of new oxime esters of cholesterol containing piperic acid-like fragments as insecticidal agents against Aphis citricola Van der Goot (Homoptera: Aphididae) and Plutella xylostella Linnaeus (Lepidoptera: Plutellidae). Bioorg Med Chem Lett 2022; 62:128634. [PMID: 35202810 DOI: 10.1016/j.bmcl.2022.128634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 01/24/2022] [Accepted: 02/17/2022] [Indexed: 11/24/2022]
Abstract
In order to application of cholesterol as pesticidal agents, a series of oxime esters of cholesterol containing piperic acid-like fragments were semi-synthesized by modification of cholesterol at the C-3 and C-6 positions. Their structures were characterized by 1H NMR, HRMS and mp, and their purity was determined by HPLC. Against Aphis citricola Van der Goot, derivatives Ib (R = 4-FPh) and In (R = 3,4-ethylenedioxystyryl) exhibited 5.0 and 4.8 folds more pronounced aphicidal activity of their precursor cholesterol. Against Plutella xylostella Linnaeus, compounds Ia (R = Ph) and If (R = 3,4-methylenedioxyphenyl) showed 2.2 and 2.0 folds more potent insecticidal activity of cholesterol. Their SARs were also observed.
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Lv M, Jiang L, Hao M, Wang H, Wang Z. Semisynthesis of Conjugates from Matrine/Cholesterol with Piperic Acid/ Piperic Acids-Like as Insecticidal and Aphicidal Agents. HETEROCYCLES 2022. [DOI: 10.3987/com-22-14675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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4
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Natural-product-based pesticides: Semisynthesis, structural elucidation, and evaluation of new cholesterol-matrine conjugates as pesticidal agents. Bioorg Med Chem Lett 2021; 50:128350. [PMID: 34478839 DOI: 10.1016/j.bmcl.2021.128350] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Revised: 08/19/2021] [Accepted: 08/26/2021] [Indexed: 11/21/2022]
Abstract
To develop new potential pesticide candidates from low value-added natural bioactive products, a series of new cholesterol-matrine conjugates (I(a-e)-IV(a-e)) were prepared from two lead compounds cholesterol and matrine. Against Mythimna separata Walker, compound IVa exhibited 3.0 and 2.6 folds promising insecticidal activity of cholesterol and matrine, respectively; against Aphis citricola Van der Goot, compound IVd showed 4.3 and 2.2 folds potent aphicidal activity of their precursors; notably, it also showed good control effects in the greenhouse; against Plutella xylostella Linnaeus at a dose of 20 μg/nymph, compound IIIe exhibited 2.8 and 2.0 folds oral toxicity of cholesterol and matrine, respectively. Compounds IIIe, IVd and IVe can be used as the leads for further structural optimization as the insecticidal and aphicidal agents.
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Homo-Tris-Nitrones Derived from α-Phenyl- N-tert-butylnitrone: Synthesis, Neuroprotection and Antioxidant Properties. Int J Mol Sci 2020; 21:ijms21217949. [PMID: 33114714 PMCID: PMC7663103 DOI: 10.3390/ijms21217949] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 10/20/2020] [Accepted: 10/21/2020] [Indexed: 12/11/2022] Open
Abstract
Herein we report the synthesis, antioxidant and neuroprotective power of homo-tris-nitrones (HTN) 1-3, designed on the hypothesis that the incorporation of a third nitrone motif into our previously identified homo-bis-nitrone 6 (HBN6) would result in an improved and stronger neuroprotection. The neuroprotection of HTNs 1-3, measured against oligomycin A/rotenone, showed that HTN2 was the best neuroprotective agent at a lower dose (EC50 = 51.63 ± 4.32 μM), being similar in EC50 and maximal activity to α-phenyl-N-tert-butylnitrone (PBN) and less potent than any of HBNs 4-6. The results of neuroprotection in an in vitro oxygen glucose deprivation model showed that HTN2 was the most powerful (EC50 = 87.57 ± 3.87 μM), at lower dose, but 50-fold higher than its analogous HBN5, and ≈1.7-fold less potent than PBN. HTN3 had a very good antinecrotic (IC50 = 3.47 ± 0.57 μM), antiapoptotic, and antioxidant (EC50 = 6.77 ± 1.35 μM) profile, very similar to that of its analogous HBN6. In spite of these results, and still being attractive neuroprotective agents, HTNs 2 and 3 do not have better neuroprotective properties than HBN6, but clearly exceed that of PBN.
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Abstract
The recent advances of tetramethylpyrazine nitrones and quinolylnitrones for the treatment of stroke have been reviewed and compared with other agents, showing promising therapeutic applications. As a result of a functional transformation of natural product ligustrazine, (Z)-N-tert-butyl-1-(3,5,6-trimethylpyrazin-2-yl)methanimine oxide (6) is a multitarget small nitrone showing potent thrombolytic activity and free radicals scavenging power, in addition to nontoxicity and blood-brain barrier permeability. Similarly, antioxidant (Z)-N-tert-butyl-1-(2-chloro-6-methoxyquinolin-3-yl)methanimine oxide (17) is a novel agent for cerebral ischemia therapy as it is able to scavenge different types of free radical species, showing strong neuroprotection and reduced infarct size.
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Affiliation(s)
- José Marco-Contelles
- Laboratory of Medicinal Chemistry, Institute of Organic Chemistry, CSIC; Juan de la Cierva, 3, 28006 Madrid, Spain
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7
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Socrier L, Rosselin M, Gomez Giraldo AM, Chantemargue B, Di Meo F, Trouillas P, Durand G, Morandat S. Nitrone-Trolox conjugate as an inhibitor of lipid oxidation: Towards synergistic antioxidant effects. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1861:1489-1501. [PMID: 31247162 DOI: 10.1016/j.bbamem.2019.06.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 06/06/2019] [Accepted: 06/16/2019] [Indexed: 12/21/2022]
Abstract
Free radical scavengers like α-phenyl-N-tert-butylnitrone (PBN) and 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox) have been widely used as protective agents in various biomimetic and biological models. A series of three amphiphilic Trolox and PBN derivatives have been designed by adding to those molecules a perfluorinated chain as well as a sugar group in order to render them amphiphilic. In this work, we have studied the interactions between these derivatives and lipid membranes to understand how they influence their ability to prevent membrane lipid oxidation. We showed the derivatives better inhibited the AAPH-induced oxidation of 1,2-dilinoleoyl-sn-glycero-3-phosphocholine (DLiPC) small unilamellar vesicles (SUVs) than the parent compounds. One of the derivatives, bearing both PBN and Trolox moieties on the same fluorinated carrier, exhibited a synergistic antioxidant effect by delaying the oxidation process. We next investigated the ability of the derivatives to interact with DLiPC membranes in order to better understand the differences observed regarding the antioxidant properties. Surface tension and fluorescence spectroscopy experiments revealed the derivatives exhibited the ability to form monolayers at the air/water interface and spontaneously penetrated lipid membranes, underlying pronounced hydrophobic properties in comparison to the parent compounds. We observed a correlation between the hydrophobic properties, the depth of penetration and the antioxidant properties and showed that the location of these derivatives in the membrane is a key parameter to rationalize their antioxidant efficiency. Molecular dynamics (MD) simulations supported the understanding of the mechanism of action, highlighting various key physical-chemical descriptors.
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Affiliation(s)
- Larissa Socrier
- Sorbonne Universités, Université de technologie de Compiègne, CNRS, Génie Enzymatique et Cellulaire, FRE 3580, Centre de recherches Royallieu, CS 60319, 60203, Compiègne cedex, France.
| | - Marie Rosselin
- Institut des Biomolécules Max Mousseron (UMR 5247 CNRS-Université Montpellier-ENSCM) & Avignon University, Equipe Chimie Bioorganique et Systèmes Amphiphiles, 301 rue Baruch de Spinoza, F-84916 Avignon Cedex 9, France
| | - Ana Milena Gomez Giraldo
- Sorbonne Universités, Université de technologie de Compiègne, CNRS, Génie Enzymatique et Cellulaire, FRE 3580, Centre de recherches Royallieu, CS 60319, 60203, Compiègne cedex, France
| | - Benjamin Chantemargue
- INSERM, Univ. Limoges, IPPRITT, U1248, Faculty of Pharmacy, 2 rue du Dr Marcland, 87025 Limoges, France; RCPTM, Palacký University, Faculty of Sciences, Šlechtitelů 27, 78371 Olomouc, Czech Republic
| | - Florent Di Meo
- INSERM, Univ. Limoges, IPPRITT, U1248, Faculty of Pharmacy, 2 rue du Dr Marcland, 87025 Limoges, France
| | - Patrick Trouillas
- INSERM, Univ. Limoges, IPPRITT, U1248, Faculty of Pharmacy, 2 rue du Dr Marcland, 87025 Limoges, France; RCPTM, Palacký University, Faculty of Sciences, Šlechtitelů 27, 78371 Olomouc, Czech Republic
| | - Grégory Durand
- Institut des Biomolécules Max Mousseron (UMR 5247 CNRS-Université Montpellier-ENSCM) & Avignon University, Equipe Chimie Bioorganique et Systèmes Amphiphiles, 301 rue Baruch de Spinoza, F-84916 Avignon Cedex 9, France
| | - Sandrine Morandat
- Sorbonne Universités, Université de technologie de Compiègne, CNRS, Génie Enzymatique et Cellulaire, FRE 3580, Centre de recherches Royallieu, CS 60319, 60203, Compiègne cedex, France
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8
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Meister A, Blume A. (Cryo)Transmission Electron Microscopy of Phospholipid Model Membranes Interacting with Amphiphilic and Polyphilic Molecules. Polymers (Basel) 2017; 9:E521. [PMID: 30965829 PMCID: PMC6418595 DOI: 10.3390/polym9100521] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 10/12/2017] [Accepted: 10/13/2017] [Indexed: 11/16/2022] Open
Abstract
Lipid membranes can incorporate amphiphilic or polyphilic molecules leading to specific functionalities and to adaptable properties of the lipid bilayer host. The insertion of guest molecules into membranes frequently induces changes in the shape of the lipid matrix that can be visualized by transmission electron microscopy (TEM) techniques. Here, we review the use of stained and vitrified specimens in (cryo)TEM to characterize the morphology of amphiphilic and polyphilic molecules upon insertion into phospholipid model membranes. Special emphasis is placed on the impact of novel synthetic amphiphilic and polyphilic bolalipids and polymers on membrane integrity and shape stability.
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Affiliation(s)
- Annette Meister
- Institute of Chemistry, Martin Luther University Halle-Wittenberg, D-06120 Halle (Saale), Germany.
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, D-06120 Halle (Saale), Germany.
| | - Alfred Blume
- Institute of Chemistry, Martin Luther University Halle-Wittenberg, D-06120 Halle (Saale), Germany.
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Socrier L, Rosselin M, Choteau F, Durand G, Morandat S. Cholesterol-nitrone conjugates as protective agents against lipid oxidation: A model membrane study. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:2495-2504. [PMID: 28982534 DOI: 10.1016/j.bbamem.2017.09.026] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 09/25/2017] [Accepted: 09/27/2017] [Indexed: 01/13/2023]
Abstract
Free radical scavengers such as α-phenyl-N-tert-butylnitrone (PBN) have been widely used as protective agents in several biological models. We recently designed two PBN derivatives by adding a cholesterol moiety to the parent nitrone to increase its lipophilicity. In addition to the cholesterol, a sugar group was also grafted to enhance the hydrophilic properties at the same time. In the present work we report on the synthesis of a third derivative bearing only a cholesterol moiety and the physical chemical and antioxidant characterization of these three derivatives. We demonstrated they were able to form stable monolayers at the air/water interface and with the two derivatives bearing a sugar group, repulsive interactions with 1,2-dilinoleoyl-sn-glycero-3-phosphocholine (DLPC) were observed. We next investigated the interaction with DLPC on a liposome model. Fluorescence spectroscopy experiments showed the addition of a cholesterol moiety causes an ordering effect whereas the presence of the sugar group led to a disordering effect. The protective effect against lipid oxidation was then investigated using dynamic light scattering and the formation of conjugated dienes was quantified spectrophotometrically. Two oxidizing systems were tested, i.e. the AAPH-thermolysis which generates peroxyl radicals and the Fenton reagent which is responsible of the formation of hydroxyl radicals. Due to their membrane localization, the three cholesteryl-PBN derivatives are able to prevent lipid oxidation with the two types of radical inducers but with a different mode of action.
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Affiliation(s)
- Larissa Socrier
- Sorbonne University, Université de technologie de Compiègne, CNRS, Laboratoire de Génie Enzymatique et Cellulaire, FRE 3580, Centre de recherches Royallieu, CS 60 319, 60 203 Compiègne Cedex, France
| | - Marie Rosselin
- Institut des Biomolécules Max Mousseron (UMR 5247 CNRS-Université Montpellier-ENSCM) & Université d'Avignon, Equipe Chimie Bioorganique et Systèmes Amphiphiles, 301 rue Baruch de Spinoza, F-84916 Avignon Cedex 9, France
| | - Fanny Choteau
- Institut des Biomolécules Max Mousseron (UMR 5247 CNRS-Université Montpellier-ENSCM) & Université d'Avignon, Equipe Chimie Bioorganique et Systèmes Amphiphiles, 301 rue Baruch de Spinoza, F-84916 Avignon Cedex 9, France
| | - Grégory Durand
- Institut des Biomolécules Max Mousseron (UMR 5247 CNRS-Université Montpellier-ENSCM) & Université d'Avignon, Equipe Chimie Bioorganique et Systèmes Amphiphiles, 301 rue Baruch de Spinoza, F-84916 Avignon Cedex 9, France
| | - Sandrine Morandat
- Sorbonne University, Université de technologie de Compiègne, CNRS, Laboratoire de Génie Enzymatique et Cellulaire, FRE 3580, Centre de recherches Royallieu, CS 60 319, 60 203 Compiègne Cedex, France.
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10
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On the vasoprotective mechanisms underlying novel β-phosphorylated nitrones: Focus on free radical characterization, scavenging and NO-donation in a biological model of oxidative stress. Eur J Med Chem 2016; 119:197-217. [PMID: 27162124 DOI: 10.1016/j.ejmech.2016.04.067] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 04/26/2016] [Accepted: 04/27/2016] [Indexed: 01/02/2023]
Abstract
A series of new hybrid 2-(diethoxyphosphoryl)-N-(benzylidene)propan-2-amine oxide derivatives with different aromatic substitution (PPNs) were synthesized. These molecules were evaluated for their EPR spin trapping potential on eleven different radicals and NO-donation properties in vitro, cytotoxicity and vasoprotective effect on precontracted rat aortic rings. A subfamily of the new PPNs featured an antioxidant moiety occurring in natural phenolic acids. From the experimental screening of these hydroxyphenyl- and methoxyphenyl-substituted PPNs, biocompatible nitrones 4d, and 4g-4i deriving from caffeic, gallic, ferulic and sinapic acids, which combined improved EPR probing of ROS formation, vasorelaxant action and antioxidant potency, might be potential drug candidate alternatives to PBN and its analogues.
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11
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Rosselin M, Meyer G, Guillet P, Cheviet T, Walther G, Meister A, Hadjipavlou-Litina D, Durand G. Divalent Amino-Acid-Based Amphiphilic Antioxidants: Synthesis, Self-Assembling Properties, and Biological Evaluation. Bioconjug Chem 2016; 27:772-81. [DOI: 10.1021/acs.bioconjchem.6b00002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Marie Rosselin
- Institut des Biomolécules Max Mousseron (UMR 5247 CNRS-Université Montpellier-ENSCM) & Avignon University, Equipe Chimie Bioorganique et Systèmes Amphiphiles, 301 rue Baruch de Spinoza, F-84916 Cedex 9 Avignon, France
| | - Grégory Meyer
- Avignon University, Laboratoire de Pharm-Ecologie
Cardiovasculaire LAPEC EA4278, F-84000 Avignon, France
| | - Pierre Guillet
- Institut des Biomolécules Max Mousseron (UMR 5247 CNRS-Université Montpellier-ENSCM) & Avignon University, Equipe Chimie Bioorganique et Systèmes Amphiphiles, 301 rue Baruch de Spinoza, F-84916 Cedex 9 Avignon, France
| | - Thomas Cheviet
- Institut des Biomolécules Max Mousseron (UMR 5247 CNRS-Université Montpellier-ENSCM) & Avignon University, Equipe Chimie Bioorganique et Systèmes Amphiphiles, 301 rue Baruch de Spinoza, F-84916 Cedex 9 Avignon, France
| | - Guillaume Walther
- Avignon University, Laboratoire de Pharm-Ecologie
Cardiovasculaire LAPEC EA4278, F-84000 Avignon, France
| | - Annette Meister
- Martin Luther University Halle—Wittenberg, Institute of Chemistry and Institute of Biochemistry/Biotechnology, von-Danckelmann-Platz 4, D-06120 Halle/Saale, Germany
| | - Dimitra Hadjipavlou-Litina
- Department
of Pharmaceutical Chemistry, School of Pharmacy, Faculty of Health
Sciences, AUTh, Thessaloniki 54124, Greece
| | - Grégory Durand
- Institut des Biomolécules Max Mousseron (UMR 5247 CNRS-Université Montpellier-ENSCM) & Avignon University, Equipe Chimie Bioorganique et Systèmes Amphiphiles, 301 rue Baruch de Spinoza, F-84916 Cedex 9 Avignon, France
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12
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Xu J, Li X, Wu J, Dai WM. Synthesis of 5-alkyl-5-aryl-1-pyrroline N-oxides from 1-aryl-substituted nitroalkanes and acrolein via Michael addition and nitro reductive cyclization. Tetrahedron 2014. [DOI: 10.1016/j.tet.2014.07.046] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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13
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Ortial S, Morandat S, Bortolato M, Roux B, Polidori A, Pucci B, Durand G. PBN derived amphiphilic spin-traps. II/Study of their antioxidant properties in biomimetic membranes. Colloids Surf B Biointerfaces 2014; 113:384-93. [DOI: 10.1016/j.colsurfb.2013.08.034] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Revised: 08/21/2013] [Accepted: 08/22/2013] [Indexed: 10/26/2022]
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14
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Potential implication of the chemical properties and bioactivity of nitrone spin traps for therapeutics. Future Med Chem 2012; 4:1171-207. [PMID: 22709256 DOI: 10.4155/fmc.12.74] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Nitrone therapeutics has been employed in the treatment of oxidative stress-related diseases such as neurodegeneration, cardiovascular disease and cancer. The nitrone-based compound NXY-059, which is the first drug to reach clinical trials for the treatment of acute ischemic stroke, has provided promise for the development of more robust pharmacological agents. However, the specific mechanism of nitrone bioactivity remains unclear. In this review, we present a variety of nitrone chemistry and biological activity that could be implicated for the nitrone's pharmacological activity. The chemistries of spin trapping and spin adduct reveal insights on the possible roles of nitrones for altering cellular redox status through radical scavenging or nitric oxide donation, and their biological effects are presented. An interdisciplinary approach towards the development of novel synthetic antioxidants with improved pharmacological properties encompassing theoretical, synthetic, biochemical and in vitro/in vivo studies is covered.
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Choteau F, Tuccio B, Villamena FA, Charles L, Pucci B, Durand G. Synthesis of tris-hydroxymethyl-based nitrone derivatives with highly reactive nitronyl carbon. J Org Chem 2012; 77:938-48. [PMID: 22188016 DOI: 10.1021/jo202098x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
A novel series of α-phenyl-N-tert-butyl nitrone derivatives, bearing a hydrophobic chain on the aromatic ring and three hydroxyl functions on the tert-butyl group, was synthesized through a short and convenient synthetic route based on a one-pot reduction/condensation of tris(hydroxymethyl)nitromethane with a benzaldehyde derivative. Because of the presence of hydroxyl functions on the tert-butyl group, an intramolecular Forrester-Hepburn reaction leading to the formation of an oxazolidine-N-oxyl compound was observed by electron paramagnetic resonance (EPR). The mechanism of cyclization was further studied by computational methods showing that intramolecular hydrogen bonding and high positive charge on the nitronyl carbon could facilitate the nucleophilic addition of a hydroxyl group onto the nitronyl carbon. At high nitrone concentrations, a second paramagnetic species, very likely formed by intermolecular nucleophilic addition of two nitrone molecules, was also observed but to a lesser extent. In addition, theoretical data confirmed that the intramolecular reaction is much more favored than the intermolecular one. These nitrones were also found to efficiently trap carbon-centered radicals, but complex spectra were observed due to the presence of oxazolidine-N-oxyl derivatives.
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Affiliation(s)
- Fanny Choteau
- Université d'Avignon et des Pays de Vaucluse, Equipe Chimie Bioorganique et Systèmes Amphiphiles, 33 rue Louis Pasteur, F-84000 Avignon, France
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