induce and strongly stabilize these structures. Sometimes, a reversible NDI-G4 interaction is also associated with an irreversible one, due to the cleavage and/or modification of G4s by functional-NDIs. This is the case of NDI-Cu-DETA, a copper(II) complex able to cleave G4s in the closest proximity to the target binding site. Herein, we present two original Cu(II)-NDI complexes, inspired by NDI-Cu-DETA
of the solubilizing moieties, and pH of the solution. Laser flash photolysis confirmed that the NDI lowest triplet excited state was efficiently populated, upon excitation at both 355 and 532 nm, and that free amine moieties quenched both the singlet and triplet excited states by intramolecular electron transfer, with generation of detectable radical anions. Time-resolved experiments, monitoring the
合成了溴和/或烷基氨基取代的水溶性萘二酰亚胺(NDI),以研究它们的多峰光物理和光化学性质。含溴的NDI(即11)在532 nm辐射下既充当单线态氧(1 O 2)光敏剂,又充当荧光分子。在不含溴的NDI中,只有12个通过在610 nm以上的辐射显示出与Br-NDI相似的光物理性质,这表明对于这些NDI,单重态和三重态的激发态性质都受到长度,加溶部分结构和溶液pH的强烈影响。激光快速光解证实,在355和532 nm激发时,NDI最低的三重激发态有效地被填充,并且游离胺部分通过分子内电子转移淬灭了单重激发态和三重激发态,并产生了可检测的自由基阴离子。通过时间分辨实验,监测在532 nm激光照射下产生的1270 nm 1 O 2磷光衰减,可以基于NDI的1 O对NDI作为敏化剂进行排名2个量子产率(Φ Δ)。经四官能化的12表现出长寿命的三重态(τ〜32μs),对于光动力疗法的应用具有最有希望的吸收性,经测试可作为有效的光敏剂用于1
Water soluble extended naphthalene diimides as pH fluorescent sensors and G-quadruplex ligands
作者:Filippo Doria、Matteo Nadai、Giovanna Sattin、Luca Pasotti、Sara N. Richter、Mauro Freccero
DOI:10.1039/c2ob07006e
日期:——
Extended naphthalene diimides (NDIs) fused to 1,4-dihydropyrazine-2,3-dione, containing two solubilizing moieties, have been synthesized. Fluorescence spectra of the new NDIs were remarkably affected by pH, as the second deprotonation of the dihydropyrazinedione moiety (pKa 6.9) switched off the emission. Binding to a G-quadruplex folded oligonucleotide and stoichiometry were evaluated by FRET melting assay and CD analysis. G-quadruplex binding was strongly enhanced shifting from pH 7.4 to pH 6.0 as a consequence of the dihydropyrazinedione moiety protonation. Cytotoxicity studies using two human telomerase-positive cell lines (HT29 and A549) revealed that the best G-quadruplex ligand was very active against the colon cell line, with an EC50 of 300 nM.
Naphthalene diimides with one or two centrosymmetric arylethynyl moieties capable of synergic donor and acceptor hydrogen bonding exhibit promising binding properties and selectivity towards parallel G-quadruplex (G4) nucleic acids (c-myc, bcl-2 and parallel hTel22). The hydrogen-bonding network involving the phosphate backbone and outside rim of the G-quartet represents an opportunity to exploit G4
作者:Filippo Doria、Matteo Nadai、Marco Folini、Marco Di Antonio、Luca Germani、Claudia Percivalle、Claudia Sissi、Nadia Zaffaroni、Stefano Alcaro、Anna Artese、Sara N. Richter、Mauro Freccero
DOI:10.1039/c2ob06816h
日期:——
The synthesis, physico-chemical properties and biological effects of a new class of naphthalene diimides (NDIs) capable of reversibly binding telomeric DNA and alkylate it through an electrophilic quinone methide moiety (QM), are reported. FRET and circular dichroism assays showed a marked stabilization and selectivity towards telomeric G4 DNA folded in a hybrid topology. NDI–QMs’ alkylating properties