mt9b01243_si_001.pdf (1.44 MB)
Thiazole Orange Styryl Derivatives as Fluorescent Probes for G‑Quadruplex DNA
journal contribution
posted on 2020-02-24, 21:04 authored by Lingling Zhang, Xiangjun Liu, Shanshan Lu, Jing Liu, Shilong Zhong, Yongbiao Wei, Tao Bing, Nan Zhang, Dihua ShangguanG-quadruplex
(G4) forming sequences commonly exist in the genome
and are closely related to gene regulation and expression. Development
of a fluorescent probe that can specifically recognize G4 is essential
for studying its structures and biological functions. Thiazole orange
(TO) is an often used nucleic acid dye that is reported to have higher
affinity to G4 DNA than double-stranded (ds) DNA. Here, four TO derivatives
were designed and synthesized by introducing different styryl groups
to obtain highly specific G4 probes. The spectroscopic studies revealed
that different groups affected the G4 binding ability greatly, in
which TO modified with 4-(diethylamino)styryl (5a) showed
better selectivity to G4s, and that modified with 4-(methylpiperazin-1-yl)styryl
(5b) showed higher affinity to antiparallel G4s. 5a and 5b bound to parallel G4s with a 1:1 molar
binding ratio, in which the binding mode of 5b to parallel
G4s was end-stacking. In addition, the obtained fluorescent probes
were tested for cell staining, which showed the potential application
in cell imaging and DNA/RNA biosensing.