- Evaluation of a series of 9,10-anthraquinones as antiplasmodial agents
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Background: A phytochemical study on medicinal plants used for the treatment of fever and malaria in Africa yielded metabolites with potential antiplasmodial activity, many of which are Anthraquinones (AQ). AQs have similar sub-structure as naphthoquinones and xanthones, which were previously reported as novel antiplasmodial agents. Objective: The present study aimed to investigate the structural requirements of 9,10-anthraquinones with hydroxy, methoxy and methyl substituents to exert strong antiplasmodial activity and to investigate their possible mode of action. Methods: Thirty-one AQs were synthesized through Friedel-Crafts reaction and assayed for antiplasmodial activity in vitro against Plasmodium falciparum (3D7). The selected compounds were tested for toxicity and probed for their mode of action against β-hematin dimerization through HRP2 and lipid catalyses. The most active compounds were subjected to a docking study using AutoDock 4.2. Results: The active AQs have similar common structural characteristics. However, it is difficult to establish a structure-activity relationship as certain compounds are active despite the absence of the structural features exhibited by other active AQs. They have either ortho- or meta-arranged substituents and one free hydroxyl and/or carbonyl groups. When C-6 is substituted with a methyl group, the activity of AQs generally increased. 1,3-DihydroxyAQ (15) showed good antiplasmodial activity with an IC50 value of 1.08 μM, and when C-6 was substituted with a methyl group, 1,3-dihydroxy-6-methylAQ (24) showed stronger antiplasmodial activity with an IC50 value of 0.02μM, with better selectivity index. Compounds 15 and 24 showed strong HRP2 activity and mild toxicity against hepatocyte cells. Molecular docking studies showed that the hydroxyl groups at the ortho (23) and meta (24) positions are able to form hydrogen bonds with heme, of 3.49 A and 3.02 A, respectively. Conclusion: The activity of 1,3-dihydroxy-6-methylAQ (24) could be due to their inhibition against the free heme dimerization by inhibiting the HRP2 protein. It was further observed that the anthraquinone moiety of compound 24 bind in parallel to the heme ring through hydrophobic interactions, thus preventing crystallization of heme into hemozoin.
- Osman, Che Puteh,Ismail, Nor Hadiani,Widyawaruyanti, Aty,Imran, Syahrul,Tumewu, Lidya,Choo, Chee Yan,Ideris, Sharinah
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p. 353 - 363
(2019/06/20)
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- Orthobromodiphenylmethane derivatives as starting materials for the total synthesis of anthraquinones
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In this communication we describe the synthesis of four simple anthraquinones by a five-step sequence, using easily available bromobenzaldehydes and phenyllithium derivatives as starting materials.
- Almeida, Wanda P.,Costa, Paulo R.R.
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p. 4507 - 4518
(2007/10/03)
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- Preparation of Anthraquinones from 10-Hydroxy-9-anthracenecarbonitriles Obtained from a Novel Aryne Annulation Reaction
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A new method for brief regioselective synthesis of anthraquinones via the reaction of anions of ethyl cyanoacetate or the anions of 2-(carbethoxyaryl)acetonitriles with arynes is described.
- Bhawal, Baburao M.,Khanapure, Subhash P.,Zhang, Hongming,Biehl, Edward R.
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p. 2846 - 2849
(2007/10/02)
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- Obtention of anthraquinones by selective oxidation of the corresponding anthracenes and 9,10-dimethoxyanthracenes with copper or zinc nitrate supported on silica gel
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Anthracene, 9,10-dimethoxyanthracene and substituted analogues are selectively oxidized to the corresponding anthraquinones in good yields by copper(II) or zinc(II) nitrate supported on silica gel; the ether groups at different position from 9 and 10 are unaffected.
- Anastasia,Allevi,Bettini,Fiecchi,Sanvito
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p. 1083 - 1084
(2007/10/02)
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- REACTIONS OF KETENE ACETALS-14; THE USE OF SIMPLE MIXED VINYLKETENE ACETALS IN THE ANNULATION OF QUINONES
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α,β- and β,γ-unsaturated esters can be converted by strong base and chlorotrimethylsilane to the corresponding mixed vinylketene acetals which are shown to be particularly useful and generally applicable reagents for the regiospecific annulation of halogenoquinones.The reaction proceeds readily with a variety of substrates including benzoquinones.
- Savard, Jacques,Brassard, Paul
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p. 3455 - 3464
(2007/10/02)
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- Selective Demethylation of Di- and Tri-methoxyanthraquinones via Aryloxydifluoroboron Chelates. Synthesis of 4-Hydroxy-1,5-dimethoxyanthraquinone and 1,4-Dihydroxy-5-methoxyanthraquinone
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Methoxyanthraquinone derivatives react with boron trifluoride-diethyl ether to give mono- and bis-difluoroboron chelates which, in methanol, are converted into hydroxyanthraquinones; an extension of this method is described for the synthesis of 2-hydroxy-2',4,4'-trimethoxybenzophenone.
- Preston, Peter N.,Winwick, Thomas,Morley, John O.
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- A New Route to Anthraquinones
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The lithium salts derived from position 3 of phthalides react with arynes to form adducts, which, upon aerial oxidation, produce anthraquinones in moderate to good yields.Substituted phthalides and arynes also participate in this general reaction.The addition to unsymmetrically substituted arynes shows regioselectivity, whilst the availability of a new general route to phthalides extends the scope of this reaction.
- Dodsworth, David J.,Calcagno, Maria-Pia,Ehrmann, E. Ursula,Devadas, Bhatt,Sammes, Peter G.
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p. 2120 - 2124
(2007/10/02)
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- Synthesis and Evaluation of Fluorescent Materials for Colour Control of Peroxyoxalate Chemiluminescence. III. Yellow and Red Fluorescent Emitters
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A number of bis(phenylethynyl)-substituted anthracenes and naphthacenes have been synthesized and their suitability as fluorescent additives for peroxyoxalate chemiluminescence evaluated.Fluorescence and chemiluminescence emission data for all compounds are presented.Both 2-chloro- and 6-chloro-5,12-bis(phenylethynyl)naphthacene provide effective scarlet chemiluminescence with the peroxyoxalate system (λmax 609 and 614 nm respectively).Althgough solutions of both compounds decolorize slowly in the presence of air and light, when used in concentrations 0f 1-5*10-3 M they allow efficient chemiluminescence for greater than 5 h.
- Hanhela, Peter J.,Paul, Brenton D.
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p. 1701 - 1717
(2007/10/02)
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- Use of alpha-di(lower alkoxy) anthraquinones in the synthesis of Alizarin Saphirols
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Alpha-dihydroxyanthraquinones used as intermediates in the synthesis of many dyestuffs, such as the Alizarin Saphirols (e.g. Color Constitution No. 63000, 63005, 63010, 63011, 63315 and 63610) can be replaced on an equimolar basis by alpha-di(lower alkoxy)anthraquinones. The alpha-di(lower alkoxy) anthraquinones can be converted in a single step, by treatment with oleum, to the corresponding alpha-dihydroxyanthraquinone-beta-disulfonic acids in almost quantitative yield. The corresponding diamine is obtained by dinitrating followed by reduction of the nitro groups. The known intermediate, leuco 1,4,5,8-tetrahydroxyanthraquinone (see C.I. No. 62500) can be obtained either by reduction of the diamine or by reduction of the dinitro compound. In one embodiment, the alpha-di(lower alkoxy)anthraquinone is obtained from dinitroanthraquinone by treatment thereof with methanol and KOH.
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