- Bismuth-catalyzed methylation and alkylation of quinone derivatives with tert-butyl peroxybenzoate as an oxidant
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A bismuth-catalyzed methylation of quinones in the presence of tert-butyl peroxybenzoate (TBPB) was developed via a radical reaction mechanism. Particularly, TBPB was used not only as an efficient oxidant, but also as a green methyl source in such transformation. Moreover, this method could also be efficiently extended to the alkylation of quinones. This reaction tolerated a series of functional groups and prepared a series of derivatives of vitamin K3 and benzoquinone. Notably, antimalarial parvaquone was synthesized by the reaction.
- Yang, Jian,Dong, Yu,He, Shuai,Shi, Zhi-Chuan,Wang, Yu,Wang, Ji-Yu
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- Multifunctional redox catalysts as selective enhancers of oxidative stress
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Certain cancer cells proliferate under conditions of oxidative stress (OS) and might therefore be selectively targeted by redox catalysts. Among these catalysts, compounds containing a chalcogen and a quinone redox centre are particularly well suited to r
- Fry, Fiona H.,Holme, Andrea L.,Giles, Niroshini M.,Giles, Gregory I.,Collins, Catriona,Holt, Kim,Pariagh, Sandra,Gelbrich, Thomas,Hursthouse, Michael B.,Gutowski, Nick J.,Jacob, Claus
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- Cytoprotective and antioxidant properties of organic selenides for the myelin-forming cells, oligodendrocytes
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Here a new series of twenty-one organoselenides, of potential protective activity, were synthesized and tested for their intrinsic cytotoxicity, anti-apoptotic and antioxidant capacities in oligodendrocytes. Most of the organoselenides were able to decrease the ROS levels, revealing antioxidant properties. Compounds 5b and 7b showed a high glutathione peroxidase (GPx)-like activities, which were 1.5 folds more active than ebselen. Remarkably, compound 5a diminished the formation of the oligodendrocytes SubG1 peak in a concentration-dependent manner, indicating its anti-apoptotic properties. Furthermore, based on the SwissADME web interface, we performed an in-silico structure-activity relationship to explore the drug-likeness of these organoselenides, predicting the pharmacokinetic parameters for compounds of interest that could cross the blood-brain barrier. Collectively, we present new organoselenide compounds with cytoprotective and antioxidant properties that can be considered as promising drug candidates for myelin diseases.
- Shaaban, Saad,Vervandier-Fasseur, Dominique,Andreoletti, Pierre,Zarrouk, Amira,Richard, Philippe,Negm, Amr,Manolikakes, Georg,Jacob, Claus,Cherkaoui-Malki, Mustapha
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- Efficacy of peptide nucleic acid and selected conjugates against specific cellular pathologies of amyotrophic lateral sclerosis
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Cellular studies have been undertaken on a nonamer peptide nucleic acid (PNA) sequence, which binds to mRNA encoding superoxide dismutase 1, and a series of peptide nucleic acids conjugated to synthetic lipophilic vitamin analogs including a recently prepared menadione (vitamin K) analog. Reduction of both mutant superoxide dismutase 1 inclusion formation and endoplasmic reticulum stress, two of the key cellular pathological hallmarks in amyotrophic lateral sclerosis, by two of the prepared PNA oligomers is reported for the first time.
- Browne, Elisse C.,Parakh, Sonam,Duncan, Luke F.,Langford, Steven J.,Atkin, Julie D.,Abbott, Belinda M.
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- Synthetic approaches to 3-amino-1,4-naphthoquinone-2-carboxylic acid derivatives and photochemical synthesis of novel 1,4,5,10-tetrahydro-5,10- dioxo-2H-naphth[2,3-d][1,3]oxazine derivatives
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Synthesis of 3-alkylamino-1,4-naphthoquinone-2-carboxylic acid (2) was attempted. Although 3-(1-piperidinyl)-1,4-naphthoquinone-2-carboxylic acid (2a) was not obtained, probably because of its instability, the esters (18a, b) of 2a could be prepared. 2-Alkylamino-3-hydroxymethyl-1,4-naphthoquinones (9a-g) were photochemically cyclized to the 1,4,5,10-tetrahydro-5,10-2H- napth[2,3-d][1,3]oxazines (19a-g), containing a novel heterocyclic ring system in moderate yields. Anti-bacterial activity of the prepared compounds was weak or insignificant.
- Ohta,Hinata,Yamashita,Kawasaki,Shoji,Yoshikawa,Obana
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- Overcoming peri- and ortho-selectivity in C-H methylation of 1-naphthaldehydes by a tunable transient ligand strategy
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Methyl groups widely exist in bioactive molecules, and site-specific methylation has become a valuable strategy for their structural functionalization. Aiming to introduce this smallest alkyl handle, a highly regioselective peri- and ortho-C-H methylation of 1-naphthaldehyde by using a transient ligand strategy has been developed. A series of methyl-substituted naphthalene frameworks have been prepared in moderate to excellent yields. Mechanistic studies demonstrate that peri-methylation is controlled by the higher electronic density of the peri-position of 1-naphthaldehyde as well as the formation of intermediary 5,6-fused bicyclic palladacycles, whereas experimental studies and theoretical calculations inferred that a 5-membered iridacycle at the ortho-position of 1-naphthaldehyde leads to energetically favorable ortho-methylation via an interconversion between the peri-iridacycle and ortho-iridacycle. Importantly, to demonstrate the synthetic utility of this method, we show that this strategy can serve as a platform for the synthesis of multi-substituted naphthalene-based bioactive molecules and natural products.
- Chen, Xiuzhen,Hu, Lihong,Jiang, Jing,Mao, Yujian,Wang, Yanan,Yuan, Dandan,Zhang, Yinan
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p. 2900 - 2908
(2022/04/03)
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- A Copper Halide Promoted Regioselective Halogenation of Coumarins Using N-Halosuccinimide as Halide Source
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A safe, convenient, and regioselective synthesis of 3-halo coumarins using a metal halide (CuX 2 alone or with ZnX 2) promoted halogenation with N -halosuccinimide (NXS) as halide source is reported. The synthesis involved the steady in situ generation of highly reactive positive halogen (X +) by the coordination of copper or zinc with the N -halosuccinimide and subsequent electrophilic aromatic substitution of the electron-deficient coumarins. This procedure works well also for the halogenation of less electron-rich naphthoquinones, flavones, and methoxypsoralen in moderate to quantitative yields. This protocol features simple experimental conditions using readily available inexpensive reagents and provides a convenient approach to the chlorination or bromination of some useful heteroaromatic compounds.
- Su, Jinling,Zhang, Yan,Chen, Mingren,Li, Weiming,Qin, Xuewei,Xie, Yanping,Qin, Lixiao,Huang, Shihua,Zhang, Min
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supporting information
p. 630 - 634
(2019/03/08)
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- Synthesis and biochemical studies of novel organic selenides with increased selectivity for hepatocellular carcinoma and breast adenocarcinoma
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Nineteen organoselenides were synthesized and tested for their intrinsic cytotoxicity in hepatocellular carcinoma (HepG2) and breast adenocarcinoma (MCF-7) cell lines and their corresponding selective cytotoxicity (SI) was estimated using normal lung fibroblast (WI-38) cells. Most of the organic selenides exhibited good anticancer activity, and this was more pronounced in HepG2 cells. Interestingly, the naphthoquinone- (5), thiazol- (12), and the azo-based (13) organic selenides demonstrated promising SI (up to 76). Furthermore, the amine 4c, naphthoquinone 5, and azo-based 13 and 15 organic selenides were able to down-regulate the expression of Bcl-2 and up-regulate the expression levels of IL-2, IL-6 and CD40 in HepG2 cells compared to untreated cells. Moreover, most of the synthesized candidates manifested good free radical-scavenging and GPx-like activities comparable to vitamin C and ebselen. The obtained results suggested that some of the presented organoselenium candidates have promising anti-HepG2 and antioxidant activities.
- Shaaban, Saad,Ashmawy, Abeer M.,Negm, Amr,Wessjohann, Ludger A.
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p. 515 - 526
(2019/07/04)
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- Iron-Catalyzed Radical Methylation of Activated Alkenes with tert -Butanol as the Methyl Source
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A free-radical-initiated methylation/addition/cyclization of N -arylacrylamides and a methylation/addition/elimination of quinines have been developed in which t -BuOH is used as a methyl source. These reactions provide effective and selective methods for the synthesis of various methylated oxindoles and quinones in moderate to good yields.
- Cao, Shouhao,Ji, Hongfang,Jia, Rui,Ma, Zhiwei,Shen, Liang,Xu, Zhengbao
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supporting information
p. 1909 - 1913
(2019/09/30)
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- Synthesis of plasmodione metabolites and 13C-enriched plasmodione as chemical tools for drug metabolism investigation
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Malaria is a tropical parasitic disease threatening populations in tropical and sub-tropical areas. Resistance to antimalarial drugs has spread all over the world in the past 50 years, thus new drugs are urgently needed. Plasmodione (benzylmenadione series) has been identified as a potent antimalarial early lead drug, acting through a redox bioactivation on asexual and young sexual blood stages. To investigate its metabolism, a series of plasmodione-based tools, including a fully 13C-labelled lead drug and putative metabolites, have been designed and synthesized for drug metabolism investigation. Furthermore, with the help of UHPLC-MS/MS, two of the drug metabolites have been identified from urine of drug-treated mice.
- Feng, Liwen,Lanfranchi, Don Antoine,Cotos, Leandro,Cesar-Rodo, Elena,Ehrhardt, Katharina,Goetz, Alice-Anne,Zimmermann, Herbert,Fenaille, Fran?ois,Blandin, Stephanie A.,Davioud-Charvet, Elisabeth
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p. 2647 - 2665
(2018/04/27)
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- Design, synthesis, and biological testing of novel naphthoquinones as substrate-based inhibitors of the quinol/fumarate reductase from Wolinella succinogenes
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Novel naphthoquinones were designed, synthesized, and tested as substrate-based inhibitors against the membrane-embedded protein quinol/fumarate reductase (QFR) from Wolinella succinogenes, a target closely related to QFRs from the human pathogens Helicobacter pylori and Campylobacter jejuni. For a better understanding of the hitherto structurally unexplored substrate binding pocket, a structure-activity relationship (SAR) study was carried out. Analogues of lawsone (2-hydroxy-1,4-naphthoquinone 3a) were synthesized that vary in length and size of the alkyl side chains (3b-k). A combined study on the prototropic tautomerism of 2-hydroxy-1,4-naphthoquinones series indicated that the 1,4-tautomer is the more stable and biologically relevant isomer and that the presence of the hydroxyl group is crucial for inhibition. Furthermore, 2-bromine-1,4-naphthoquinone (4a-c) and 2-methoxy-1,4-naphthoquinone (5a-b) series were also discovered as novel and potent inhibitors. Compounds 4a and 4b showed IC50 values in low micromolar range in the primary assay and no activity in the counter DT-diaphorase assay.
- Nasiri, Hamid Reza,Madej, M. Gregor,Panisch, Robin,Lafontaine, Michael,Bats, Jan W.,Lancaster, C. Roy D.,Schwalbe, Harald
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p. 9530 - 9541
(2014/01/06)
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- 2,3-Dimethoxy-5-methyl-1,4-benzoquinones and 2-methyl-1,4-naphthoquinones: Glycation inhibitors with lipid peroxidation activity
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Anti-glycation activity of our anti-oxidant quinone library was measured and several 2,3-dimethoxy-5-methyl-1,4-benzoquinones and 2-methyl-1,4- naphthoquinones were identified as novel inhibitors of glycation, of which 2,3-dimethoxy-5-methyl-1,4-benzoquinones 13b is the most potent glycation inhibitor with around 50 μM of the IC50 value.
- Jung, Young-Sik,Joe, Bo-Young,Cho, Sung Ju,Konishi, Yasuo
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p. 1125 - 1129
(2007/10/03)
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- Selective methylation of coumarins and naphthoquinones using dimethyl sulfoxide
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On UV irradiation, coumarins 1-6 and 1,4-naphthoquinones 7-11 with dimethyl sulfoxide in tertiary butyl alcohol under nitrogen atmosphere give corresponding 4-methylcoumarins 12-17 and 2-methyl-1,4-naphthoquinones 18-22 selectively in a single step facile reaction with good yields.
- Thapliyal, Prakash Chander
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p. 726 - 727
(2007/10/03)
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- Microwave induced selective bromination of 1,4-quinones and coumarins
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Microwave irradiation accelerates the bromination of 1,4-quinones and coumarins with (i) bromide adsorbed on neutral alumina in 'dry media' and (ii) with iodine monobromide on acetic acid as compared to the reactions run at room temperature. Bromination takes place selectively at active quinonoid position in 1,4-quinones and at α,β-double bond in coumarins.
- Bansal, Vandana,Kanodia, Saraswati,Thapliyal, Prakash C.,Khanna, Rajinder N.
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p. 887 - 892
(2007/10/03)
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- Dimethyl sulfoxide and anhydrous copper (II) sulfate as alkylating reagent for 1,4-quinones
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1,4-Quinones and its derivatives have been alkylated by dimethyl sulfoxide in the presence of anhydrous copper (II) sulfate at the active quinonoid position selectively, in a facile single step reaction with good yields.
- Bansal,Thapliyal,Khanna
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p. 1669 - 1675
(2007/10/02)
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- Selective halogenation of 1,4-benzoquinones and 1,4-naphthoquinones with copper(II) halide adsorbed on alumina
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1,4-Benzoquinone or 1,4-naphthoquinone and their derivatives have been halogenated selectively at quinonoid positions with copper(II) halide adsorbed on neutral alumina followed by refluxing in halobenzene to give mono-, di-, tri- and tetra-haloquinones.
- Singh,Khanna
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p. 2083 - 2089
(2007/10/02)
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- The Formal Oxidative Addition of Electron-Rich Transoid Dienes to Bromonaphthoquinones
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This work established the idea that a halogen atom, such as bromine, will act as a control element in the regiospecific formation of a new carbon-carbon bond.The addition of the electron-rich end of a transoid diene to a bromojuglone dervative occurred exclusively at the unsubstituted carbon of the quinone.Thus, 2,2-dimethyl-4-methoxy-6-methylene-1,3-dioxa-2-sila-4-cyclohexene (3) and either 2- or 3-bromo-5-hydroxy-1,4-naphthoquinone (1 or 2) afforded the adducts 19 or 20 in 57percent or 71percent yield.Similarly, 2,2-dimethyl-6-methylene-4-(trimethylsiloxy)-1,3-diox-4-ene (4) and 1 gave 21 in 77percent yield.
- Grunwell, John R.,Karipides, Anastas,Wigal, Carl T.,Heinzman, Stephen W.,Parlow, John,et al.
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