- Self-assembled naphthalenediimide derivative films for light-assisted electrochemical reduction of oxygen
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This naphthalene diimide derivative, DC18, forms highly conjugated semiconducting stacked assemblies over electrodes after electrochemical conditioning. These molecular materials are very efficient towards electrochemical photoreduction of oxygen under visible light.
- Castaldelli, Evandro,Triboni, Eduardo Rezende,Demets, Gregoire Jean-Franois
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- Spectroscopic and structural characterization of the charge-transfer interaction of N,N′-bis-alkyl derivatives of 1,4,6,8-naphthalenediimide with chloranilic and picric acids
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Charge-transfer (CT) complexes formed from the reactions of two N,N′-bis-alkyl derivatives of 1,4,6,8-naphthalenediimide such as N,N′-bis[2-hydroxyethyl)]-1,4,6,8-naphthalenediimide (BHENDI) and N,N′-bis-[2-N,N-dimethylaminoethyl)]-1,4,6,8-naphthalenediimide (BDMAENDI) with chloranilic acid (CLA) and piciric acid (PA) as π-acceptors, have been studied spectrophotometrically in methanol and chloroform, respectively at 25 °C. The photometric titration curves for the reactions indicated that the data obtained refer to 1:1 charge-transfer complexes of [(BHENDI)(CLA)], [(BDMAENDI)(CLA)], [(BHENDI)(PA)] and [(BDMAENDI)(PA)] were formed. Benesi-Hildebrand and its modification methods were applied to the determination of association constant (K), molar extinction coefficient (ε). The solid CT complexes have been synthesized and characterization by different spectral methods.
- Refat, Moamen S.,Ahmed, Hamdy A.,Grabchev, Ivo,El-Zayat, Lamia A.
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- Tri-, tetra- and heptacyclic perylene analogues as new potential antineoplastic agents based on DNA telomerase inhibition
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A recent approach in anticancer chemotherapy envisages telomerase as a potentially useful target. An attractive strategy deals with the development of compounds able to stabilize telomeric DNA in the G-quadruplex folded structure and, among them, a prominent position is found in the perylenes. With the aim to further investigate the role of drug structure, in view of possible pharmaceutical applications, we synthesized a series of compounds related to PIPER, a well-known perylene-based telomerase inhibitor. We modified the number of condensed aromatic rings and introduced different side chains to modulate drug protonation state and extent of self-aggregation. Effective telomerase inhibition was induced by heptacyclic analogues only, some showing a remarkably wide selectivity index with reference to inhibition of Taq polymerase. G-quadruplex stabilization was monitored by circular dichroism and melting experiments. Cell cytotoxicity measurements indicated a poor short-term cell killing ability for the best G-quartet binders. Besides the presence of a planar seven-condensed ring system, the introduction of a cyclic amine in the side chains critically affects the selectivity window.
- Sissi, Claudia,Lucatello, Lorena,Paul Krapcho,Maloney, David J.,Boxer, Matthew B.,Camarasa, Maria V.,Pezzoni, Gabriella,Menta, Ernesto,Palumbo, Manlio
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- Spectral properties of new N,N′-bis-alkyl-1,4,6,8-naphthalenediimide complexes
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The photophysical properties of two N,N′-bis-alkyl-1,4,6,8-naphthalenediimide (DCN1 and DCN2) have been studied in chloroform and N,N-dimethylformamide solvents. The ability of DCN2 in N,N-dimethylformamide to detect metal cations have been monitored by the fluorescence emission spectroscopy. It has been shown that the fluorescent intensity is very sensitive to the concentration of Fe3+ cations. The reaction of iodine with N,N′-bis-alkyl-1,4,6,8-naphthalenediimide in chloroform solution have been investigated by spectrophotometric method. The results indicate the formation of two CT-complexes [(DCN1)I]+·I3- and [(DCN2)I]+·I3- at donor:acceptor molar ratio of 1:2. The [(DCN1)I]+·I3- shows the characteristic absorptions of I3- ion at 290 and 360 nm while the charge-transfer transition of [(DCN2)I]+·I3- occurs at 310 nm. Three characteristic bands at the far infrared region in each iodine complex are observed around 135, 105 and 85 cm-1 due to νas (I-I), νs (I-I) and δ (I3-), respectively with C2v symmetry. The values of the complex formation constant, K, and the absorptivity, ε have been calculated.
- Refat,Grabchev,Chovelon,Ivanova
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- Thiosugar naphthalene diimide conjugates: G-quadruplex ligands with antiparasitic and anticancer activity
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Glycosyl conjugation to drugs is a strategy being used to take advantage of glucose transporters (GLUT) overexpression in cancer cells in comparison with non-cancerous cells. Its extension to the conjugation of drugs to thiosugars tries to exploit their higher biostability when compared to O-glycosides. Here, we have synthesized a series of thiosugar naphthalene diimide conjugates as G-quadruplex ligands and have explored modifications of the amino sidechain comparing dimethyl amino and morpholino groups. Then, we studied their antiproliferative activity in colon cancer cells, and their antiparasitic activity in T. brucei and L. major parasites, together with their ability to bind quadruplexes and their cellular uptake and location. We observed higher toxicity for the sugar-NDI-NMe2 derivatives than for the sugar-NDI-morph compounds, both in mammalian cells and in parasites. Our experiments indicate that a less efficient binding to quadruplexes and a worse cellular uptake of the carb-NDI-morph derivatives could be the reasons for these differences. We found small variations in cytotoxicity between O-carb-NDIs and S-carb-NDIs, except against non-cancerous human fibroblasts MRC-5, where thiosugar-NDIs tend to be less toxic. This leads to a notable selectivity for β-thiomaltosyl-NDI-NMe2 12 (9.8 fold), with an IC50 of 0.3 μM against HT-29 cells. Finally, the antiparasitic activity observed for the carb-NDI-NMe2 derivatives against T. brucei was in the nanomolar range with a good selectivity index in the range of 30- to 69- fold.
- Belmonte-Reche, Efres,Benassi, Alessandra,Cucchiarini, Anne,Doria, Filippo,Freccero, Mauro,Gabelica, Valerie,Mergny, Jean Louis,Morales, Juan Carlos,Guédin, Aurore,Pe?alver, Pablo,Rosu, Frèdèric
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- Aqueous Phase Phosphorescence: Ambient Triplet Harvesting of Purely Organic Phosphors via Supramolecular Scaffolding
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Ambient solution and amorphous state room temperature phosphorescence (RTP) from purely organic chromophores is rarely achieved. Remarkable stabilization of triplet excitons is realized to obtain deep red phosphorescence in water and in amorphous film state under ambient conditions by a unique supramolecular hybrid assembly between inorganic laponite clay and heavy atom core substituted naphthalene diimide (NDI) phosphor. Structural rigidity and oxygen tolerance of the inorganic template along with controlled molecular organization via supramolecular scaffolding are envisaged to alleviate the unprecedented aqueous phase phosphorescence.
- Kuila, Suman,Rao, K. Venkata,Garain, Swadhin,Samanta, Pralok K.,Das, Shubhajit,Pati, Swapan K.,Eswaramoorthy, Muthusamy,George, Subi J.
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supporting information
p. 17115 - 17119
(2018/12/11)
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- Photoinduced color change and photomechanical effect of naphthalene diimides bearing alkylamine moieties in the solid state
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Photoinduced color change of naphthalene diimides (NDIs) bearing alkylamine moieties has been observed in the solid state. The color change is attributed to the generation of a NDI radical-anion species, which may be formed through a photoinduced electron-transfer process from the alkylamine moiety to the NDI. The photosensitivity of NDIs is highly dependent on the structures of the alkylamine moieties. Crystallographic analysis, kinetic analysis, UV/Vis/NIR spectroscopic measurements, and analysis of the photoproduct suggested that a radical anion was formed through an irreversible process initiated by proton abstraction between an amine radical cation and the neutral amine moiety. The radical anions formed stacks including mixed-valence stacks and radical-anion stacks, as shown by the broad absorption bands in near-IR spectra. These photosensitive NDIs also showed crystal bending upon photoirradiation, which may be associated with a change in the intermolecular distance of the NDI stacks by the formation of monomeric radical anions, mixed-valence stacks, and radical-anion stacks.
- Matsunaga, Yuki,Goto, Kenta,Kubono, Koji,Sako, Katsuya,Shinmyozu, Teruo
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supporting information
p. 7309 - 7316
(2014/06/23)
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- NAPHTHALENE DIIMIDE COMPOUNDS INTERACTING WITH G-QUADRUPLEX REGIONS IN DNA
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The invention relates to novel compounds which are naphthalene diimides of general formula (I). The compounds are used in therapy, particularly in cancer treatment.
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Page/Page column 29
(2009/07/03)
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- Tri- and tetra-substituted naphthalene diimides as potent G-quadruplex ligands
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A series of tri- and tetra-substituted naphthalene diimides have been designed and synthesized. Several compounds show exceptional affinity for telomeric G-quadruplex DNA in classical and competition FRET assays and SPR studies. They inhibit telomerase in the TRAP assay, and show potent senescence-based short-term anti-proliferative effects on MCF7 and A549 cancer cell lines, and localize in the nucleus and particularly the nucleolus of MCF7 cells.
- Cuenca, Francisco,Greciano, Olga,Gunaratnam, Mekala,Haider, Shozeb,Munnur, Deeksha,Nanjunda, Rupesh,Wilson, W. David,Neidle, Stephen
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p. 1668 - 1673
(2008/12/21)
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- Tethered naphthalene diimide intercalators enhance DNA triplex stability
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Naphthalene diimides function as effective intercalators and when tethered to the 5'-terminus of a pyrimidine-rich oligonucleotide can contribute significantly to the overall stabilization of DNA triplexes. This stabilization can be further enhanced by al
- Gianolio, Diego A.,McLaughlin, Larry W.
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p. 2329 - 2334
(2007/10/03)
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- The synthesis and screening of 1,4,5,8-naphthalenetetracarboxylic diimide-peptide conjugates with antibacterial activity
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We have employed an initial combinatorial approach followed by systematic lead optimization to investigate a series of novel molecules that exhibit antimicrobial activity against Gram-negative and Gram-positive bacteria. The new molecules contain various sequences of amino acids, generally L-lysine and glycine, attached to the 1,4,5,8-naphthalenetetracarboxylic diimide aromatic unit. Systematic structure-activity studies found that increasing positive charge enhanced activity and molecules containing one naphthalenetetracarboxylic diimide unit as well as at least seven lysine residues were optimum for antimicrobial activity. The naphthalenetetracarboxylic diimide derivatives were found to be inactive against mammalian cell lines, making them excellent antimicrobial candidates. Our results indicate that combining positive charge with aromatic and/or hydrophobic elements may be an interesting new approach to antimicrobial agents and adds an important new dimension to the field of cationic peptides.
- Miller, Chandra T.,Weragoda, Ramal,Izbicka, Elzbieta,Iverson, Brent L.
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p. 2015 - 2024
(2007/10/03)
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