Department of Chemistry-Biology, University of Siegen, Center of Micro- and Nanochemistry and Engineering (Cµ), Adolf-Reichwein-Str. 2, 57068 Siegen, Germany.
Molecules. 2021 Apr 28;26(9):2566. doi: 10.3390/molecules26092566.
A phosphate-substituted, zwitterionic berberine derivative was synthesized and its binding properties with duplex DNA and G4-DNA were studied using photometric, fluorimetric and polarimetric titrations and thermal DNA denaturation experiments. The ligand binds with high affinity toward both DNA forms ( = 2-7 × 10 M) and induces a slight stabilization of G4-DNA toward thermally induced unfolding, mostly pronounced for the telomeric quadruplex . The ligand likely binds by aggregation and intercalation with ct DNA and by terminal stacking with G4-DNA. Thus, this compound represents one of the rare examples of phosphate-substituted DNA binders. In an aqueous solution, the title compound has a very weak fluorescence intensity ( < 0.01) that increases significantly upon binding to G4-DNA ( = 0.01). In contrast, the association with duplex DNA was not accompanied by such a strong fluorescence light-up effect ( < 0.01). These different fluorimetric responses upon binding to particular DNA forms are proposed to be caused by the different binding modes and may be used for the selective fluorimetric detection of G4-DNA.
合成了一种磷酸取代的两性离子小檗碱衍生物，并通过光度法、荧光法和偏振滴定以及热 DNA 变性实验研究了其与双链 DNA 和 G4-DNA 的结合性质。该配体与两种 DNA 形式（ = 2-7×10^M）具有高亲和力，并诱导 G4-DNA 对热诱导解折叠略有稳定，对于端粒四聚体尤为明显。配体可能通过与 ctDNA 的聚集和嵌入以及与 G4-DNA 的末端堆积结合。因此，该化合物代表了少数磷酸取代的 DNA 结合物之一。在水溶液中，标题化合物的荧光强度非常弱（<0.01），但与 G4-DNA 结合时会显著增加（ = 0.01）。相比之下，与双链 DNA 的结合没有伴随如此强烈的荧光增强效应（<0.01）。这些与特定 DNA 形式结合时不同的荧光响应被认为是由不同的结合模式引起的，并可用于 G4-DNA 的选择性荧光检测。
