University of Siegen, Organic Chemistry II, Adolf-Reichwein-Str. 2, D-57068, Siegen, Germany.
Org Biomol Chem. 2013 Jan 21;11(3):480-7. doi: 10.1039/c2ob26779a. Epub 2012 Nov 30.
The interactions of a triangle-shaped [2.2.2]heptamethinecyanine dye 1, namely 1,5,7-tris-[3-methylbenzothiazol-2-yl]-[2.2.2]heptamethindiium, with quadruplex DNA were studied with photometric and fluorimetric titrations, thermal DNA denaturation, CD and (1)H-NMR spectroscopy. The ligand binds to the quadruplex DNA with moderate affinity (K = 8 × 10(5) M(-1)), mainly by terminal π stacking. Remarkably, the ligand 1 exhibits a selectivity for quadruplex DNA relative to duplex DNA. Whereas the cyanine dye is very weakly fluorescent in aqueous solution, the emission intensity increases by a factor of >100 upon association with quadruplex DNA. Thus, it is shown that trinuclear cyanine derivatives may be employed as selective probes for the fluorimetric detection of quadruplex DNA.
用光度法和荧光滴定法、热 DNA 变性、CD 和 (1)H-NMR 光谱法研究了三角形[2.2.2]庚甲烯氰染料 1（即 1,5,7-三-[3-甲基苯并噻唑-2-基]-[2.2.2]庚甲烯三碘化物）与四链体 DNA 的相互作用。该配体与四链体 DNA 具有中等亲和力（K=8×10(5)M(-1)），主要通过末端π堆积结合。值得注意的是，与双链 DNA 相比，配体 1 对四链体 DNA 具有选择性。尽管在水溶液中氰染料的荧光非常弱，但与四链体 DNA 结合后，其发射强度增加了>100 倍。因此，证明三核氰衍生物可作为选择性荧光探针用于四链体 DNA 的荧光检测。
