- Photoreversible prodrugs and protags: Switching the release of maleimides by using light under physiological conditions
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A water-soluble furyl-substituted diarylethene derivative has been prepared that can undergo reversible Diels-Alder reactions with maleimides to yield photoswitchable Diels-Alder adducts. Employing bioorthogonal visible light, the release of therapeutically effective concentrations of maleimide-based reactive inhibitors or labels from these "prodrugs" or "protags" could be photoreversibly triggered in buffered, aqueous solution at body temperature. It is shown how the release properties can be fine-tuned and a thorough investigation of the release dynamics is presented. Our system should allow for spatiotemporal control over the inhibition and labeling of specific protein targets and is ready to be surveyed in living organisms.
- G?stl, Robert,Hecht, Stefan
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- Iron(II) phenanthroline-resin hybrid as a visible light-driven heterogeneous catalyst for green oxidative degradation of organic dye
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A novel resin immobilized iron(II) phenanthroline [FePR] is prepared, characterized and exploited to understand C-C/C-O cleavage in Rhodamine B dye under visible light.
- Rakibuddin, Md.,Gazi, Sarifuddin,Ananthakrishnan, Rajakumar
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- 9,10-Dibromo-N-aryl-9,10-dihydro-9,10-[3,4]epipyrroloanthracene-12,14-diones: Synthesis and Investigation of Their Effects on Carbonic Anhydrase Isozymes I, II, IX, and XII
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N-substituted maleimides were synthesized from maleic anhydride and primary amines. 1,4-Dibromo-dibenzo[e,h]bicyclo-[2,2,2]octane-2,3-dicarboximide derivatives (4a-f) were prepared by the [4+2] cycloaddition reaction of dibromoanthracenes with the N-substituted maleimide derivatives. The carbonic anhydrase (CA, EC 4.2.1.1) inhibitory effects of the new derivatives were assayed against the human (h) isozymes hCA I, II, IX, and XII. All tested bicyclo dicarboximide derivatives exhibited excellent inhibitory effects in the nanomolar range, with Ki values in the range of 117.73-232.87 nM against hCA I and of 69.74-111.51 nM against hCA II, whereas they were low micromolar inhibitors against hCA IX and XII. A series of 9,10-dibromo-N-aryl-9,10-dihydro-9,10-[3,4]epipyrroloanthracene-12,14-diones (4a-f) were synthesized from N-substituted maleimide derivatives and 9,10-dibromoanthracene. Compounds 4a-f were assayed against human carbonic anhydrases (hCA) IX and XII, which are the two tumor-associated isozymes, and hCA I and II, which represent the most common off-targets for the development of selective anticancer CA inhibitors.
- G?ksu, Haydar,Topal, Meryem,Keskin, Ali,Gültekin, Mehmet S.,?elik, Murat,Gül?in, Ilhami,Tanc, Muhammet,Supuran, Claudiu T.
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- Visible-Light-Mediated Efficient Metal-Free Catalyst for α-Oxygenation of Tertiary Amines to Amides
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A metal-free system has been discovered for the efficient α-oxygenation of tertiary amines to the corresponding amides using oxygen as an oxidant. This visible-light-mediated oxygenation reaction exhibited excellent substrates scope under mild reaction conditions and generated water as the only byproduct. The synthetic utility of this approach has been demonstrated by applying onto drug molecules. At the end, detailed mechanistic reactions clearly showed the role of oxygen and the photocatalyst.
- Zhang, Yu,Riemer, Daniel,Schilling, Waldemar,Kollmann, Jiri,Das, Shoubhik
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p. 6659 - 6664
(2018/06/25)
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- Catalyst and Additive-Free Diastereoselective 1,3-Dipolar Cycloaddition of Quinolinium Imides with Olefins, Maleimides, and Benzynes: Direct Access to Fused N,N′-Heterocycles with Promising Activity against a Drug-Resistant Malaria Parasite
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A convenient and eco-friendly synthesis of various fused N-heterocyclic compounds through catalyst and additive-free 1,3 dipolar cycloadditions of quinolinium imides with olefins, maleimides, and benzynes in excellent yields and diastereoselectivities is reported. The thermally controlled diastereoselective [3 + 2] cycloaddition reaction between quinolinium imides and olefins provided cis-isomers at low temperature and trans-isomers at high temperature. A reaction between quinolinium imides with substituted maleimides gave four-ring-fused N-heterocyclic compounds in high yields as a single diastereomer. The aryne precursors also provided four-ring-fused N,N′-heterocyclic compounds in high yields. The in vitro antiplasmodial activity of selected molecules revealed that this class of molecules possesses potential for ongoing studies against malaria.
- Kumar, Rakesh,Chaudhary, Sandeep,Kumar, Rohit,Upadhyay, Pooja,Sahal, Dinkar,Sharma, Upendra
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p. 11552 - 11570
(2018/09/25)
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- Cp?Co(III)-Catalyzed C-H Alkylation with Maleimides Using Weakly Coordinating Carbonyl Directing Groups
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A novel protocol for ortho-C-H alkylation of aromatic and heteroaromatic ketones and esters under Cp?Co(III) catalysis has been developed for the first time. The reaction proceeds through initial cyclometalation via weak chelation-assisted C-H bond activation, followed by coordination of activated alkene, insertion between Co-C, and protodemetalation.
- Mandal, Rajib,Emayavaramban, Balakumar,Sundararaju, Basker
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supporting information
p. 2835 - 2838
(2018/05/29)
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- Graphene Oxide as a Carbocatalyst for a Diels–Alder Reaction in an Aqueous Medium
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The Diels–Alder (DA) reaction, a [4+2] cycloaddition reaction, is highly important in synthetic organic chemistry and is frequently used in the synthesis of natural products containing six-membered rings. Herein, we report an efficient protocol for the DA reaction between 9-hydroxymethylanthracene and N-substituted maleimides using two-dimensional graphene oxide (GO) as a heterogeneous carbocatalyst in an aqueous medium at room temperature. High yields, a wide substrate scope, low temperature, excellent functional group tolerance, atom economy, and water as a green solvent are noteworthy features of this protocol. The heterogeneous GO catalyst can be easily recovered and used multiple times without any significant loss in catalytic activity.
- Girish, Yarabhally R.,Pandit, Subrata,Pandit, Subhendu,De, Mrinmoy
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supporting information
p. 2393 - 2398
(2017/09/11)
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- An approach to "escape from flatland": Chemo-enzymatic synthesis and biological profiling of a library of bridged bicyclic compounds
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A major reason for the low success rate in current drug development through chemical synthesis has been ascribed to the large fraction of quasi planar candidate molecules. Therefore, an "escape from flatland" strategy has been recommended for the generation of bioactive chemical entities. In a first attempt to test this recommendation, we synthesized a small collection of bridged bicyclic compounds possessing a rigid spherical core structure by combining a group of cyclic dienes with a collection of dienophiles. We started from planar biphenyl analogues and, by enzymatic dioxygenation, transformed them into hydroxylated diene structures. Using a small library of newly synthesized dienophiles, the dienes were converted into bridged bicycles via the Diels-Alder reaction. The resulting collection of 78 structures was first tested for bioactivity in a generic assay based on interference with the proliferation of mammalian cells. A more mechanism-targeted bioactivity profiling method, exploiting cellular impedance monitoring, was subsequently used to obtain suggestions for the mode of action exerted by those compounds that were the most active in the proliferation assay. Proteasome inhibition could be confirmed for 8 of a series of 9 respective candidates. Whilst 7 of these molecules showed relatively weak interference with proteasome activity, one candidate exerted a moderate but distinct inhibition. This result appears remarkable in view of the small size of the compound library, which was synthesized following a few basic considerations. It encourages the application of diverse synthetic approaches to further investigate the role of spherical shape for the success of compound libraries.
- Suryanarayana Birudukota,Franke, Raimo,Hofer, Bernd
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p. 3821 - 3837
(2016/05/09)
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- Potent Nematicidal Activity of Maleimide Derivatives on Meloidogyne incognita
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Different maleimide derivatives were synthesized and assayed for their in vitro activity on the soil inhabiting, plant-parasitic nematode Meloidogyne incognita, also known as root-knot nematode. The compounds maleimide, N-ethylmaleimide, N-isopropylmaleimide, and N-isobutylmaleimide showed the strongest nematicidal activity on the second stage juveniles of the root-knot nematode with EC50/72h values of 2.6 ± 1.3, 5.1 ± 3.4, 16.2 ± 5.4, and 19.0 ± 9.0 mg/L, respectively. We also determined the nematicidal activity of copper sulfate, finding an EC50 value of 48.6 ± 29.8 mg/L. When maleimide at 1 mg/L was tested in combination with copper sulfate at 50 mg/L, we observed 100% mortality of the nematodes. We performed a GC-MS metabolomics analysis after treating nematodes with maleimide at 8 mg/L for 24 h. This analysis revealed altered fatty acids and diglyceride metabolites such as oleic acid, palmitic acid, and 1-monopalmitin. Our results suggest that maleimide may be used as a new interesting building block for developing new nematicides in combination with copper salts.
- Eloh, Kodjo,Demurtas, Monica,Mura, Manuel Giacomo,Deplano, Alessandro,Onnis, Valentina,Sasanelli, Nicola,Maxia, Andrea,Caboni, Pierluigi
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p. 4876 - 4881
(2016/07/06)
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- Chemical reactivity and antimicrobial activity of N-substituted maleimides
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Several N-substituted maleimides containing substituents of varying bulkiness and polarity were synthesised and tested for antimicrobial and cytostatic activity. Neutral maleimides displayed relatively strong antifungal effect minimum inhibitory concentrations (MICs in the 0.54 g ml-1 range); their antibacterial activity was structure dependent and all were highly cytostatic, with IC50 values below 0.1 g ml-1. Low antimicrobial but high cytostatic activity was noted for basic maleimides containing tertiary aminoalkyl substituents. Chemical reactivity and lipophilicity influenced antibacterial activity of neutral maleimides but had little if any effect on their antifungal and cytostatic action. N-substituted maleimides affected biosynthesis of chitin and β(1,3)glucan, components of the fungal cell wall. The membrane enzyme, β(1,3)glucan synthase has been proposed as a putative primary target of N-ethylmaleimide and some of its analogues in Candida albicans cells.
- Salewska, Natalia,Boros-Majewska, Joanna,Lcka, Izabela,Chylinska, Katarzyna,Sabisz, Michal,Milewski, Slawomir,Milewska, Maria J.
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scheme or table
p. 117 - 124
(2012/04/18)
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- Using light and a molecular switch to 'lock' and 'unlock' the Diels-Alder reaction
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Light is used to 'gate' the Diels-Alder reaction using a photoresponsive dithienylfuran backbone and turn the reversibility of the Diels-Alder reaction 'off' and 'on' at 100 °C. These features make the reported system an excellent candidate for developing the next generation of self-healing polymers and photothermal drug delivery vehicles.
- Erno, Zach,Asadirad, Amir Mahmoud,Lemieux, Vincent,Branda, Neil R.
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p. 2787 - 2792,6
(2020/08/31)
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- Rigidized 1-aryl sulfonyl tryptamines: Synthesis and pharmacological evaluation as 5-HT6 receptor ligands
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A series of N1-arylsulfonyl-3-(pyrrolidin-3-yl)-1H-indole and N1-arylsulfonyl-3-(4-chloro-2,5-dihydro-1H-pyrrol-3-yl)-1H-indole derivatives (tryptamine derivatives with rigidized side chain) have been prepared and tested for their binding affinity to 5-HT6 receptor. Several compounds displayed potent binding affinity for the 5-HT6 receptor when tested in in vitro binding assay. The primary SAR indicates that rigidification of dimethylamino alkyl chain at C3 of indole carbon maintains the binding affinity to 5-HT6R. The lead compound N 1-benzenesulfonyl-3-(4-chloro-1-methyl-2,5-dihydro-1H-pyrrol-3-yl) -1H-indole, 10a (Kb = 0.1 nM) has shown excellent in vitro affinity and was active in animal models of cognition like NORT and water maze.
- Nirogi, Ramakrishna,Dwarampudi, Adireddy,Kambhampati, Ramasastry,Bhatta, Venugopalarao,Kota, Laxman,Shinde, Anil,Badange, Rajesh,Jayarajan, Pradeep,Bhyrapuneni, Gopinadh,Dubey
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supporting information; experimental part
p. 4577 - 4580
(2011/09/12)
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- Treatment solution and method for preventing posterior capsular opacification by selectively inducing detachment and/or death of lens epithelial cells
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A treatment solution used to prevent posterior capsular opacification is applied or introduced into the lens capsular bag before, during, or after cataract surgery. The treatment solution may also be applied to an intraocular lens prior to surgery. The treatment solution comprises an ion transport mechanism interference agent, which either alone or in combination with other treatment agents such as an osmotic stress agent and an agent to establish a suitable pH, selectively induces detachment and/or death of lens epithelial cells such that posterior capsular opacification is prevented. While the ion transport mechanism interference agent is capable of interfering with the cellular mechanisms and cell ion distribution of a broad range of cells, a concentration of agent is selected such that the treatment solution interferes selectively with the cellular mechanisms of lens epithelial cells while leaving other ocular cells substantially unharmed. The treatment solution selectively induces cellular death and/or detachment of lens epithelial cells while other ocular cells and tissue remain substantially unharmed and without lengthy preoperative pre-treatment.
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- Treatment solution and method for preventing posterior capsular opacification by selectively inducing detachment and/or death of lens epithelial cells
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A treatment solution used to prevent posterior capsular opacification is applied or introduced into the lens capsular bag before, during, or after cataract surgery. The treatment solution comprises an ion transport mechanism interference agent, which either alone or in combination with other treatment agents such as an osmotic stress agent and an agent to establish a suitable pH, selectively induces detachment and/or death of lens epithelial cells such that posterior capsular opacification is prevented. While the ion transport mechanism interference agent is capable of interfering with the cellular mechanisms and cell ion distribution of a broad range of cells, a concentration of agent is selected such that the treatment solution interferes selectively with the cellular mechanisms of lens epithelial cells while leaving other ocular cells substantially unharmed. The treatment solution selectively induces cellular death and/or detachment of lens epithelial cells while other ocular cells and tissue remain substantially unharmed and without lengthy preoperative pre-treatment.
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- Process for preparation of N-substituted maleimides
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N-substituted maleimide represented by formula (2): STR1 is produced from N-substituted maleamic acid monoester represented by formula (1): STR2 in the presence of an acid catalyst by elmination of an alcohol from the monoester. The above N-substituted maleamic acid monoester represented by formula (1) is produced by esterification of N-substituted maleamic acid represented by formula (3): STR3 with an alcohol R2 -OH in the represence of an acid catalyst.
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