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.
合成了扩展的萘二酰亚胺(NDIs),与1,4-二氢吡嗪-2,3-二酮融合,并包含两个溶解化基团。新合成的NDIs的荧光光谱明显受到pH的影响,因为二氢吡嗪二酮基团的第二个去质子化(pKa 6.9)会关闭发射。通过FRET熔解分析和CD分析评估了与G-四链体折叠的寡核苷酸的结合和化学计量。随着pH从7.4下降到6.0,由于二氢吡嗪二酮基团的质子化,G-四链体结合显著增强。对两种人类端粒酶阳性细胞系(HT29和A549)的细胞毒性研究显示,最佳的G-四链体配体对结肠细胞系具有非常活跃的作用,EC50为300 nM。