Publication Date:
2018
Description:
〈p〉Publication date: 15 March 2019〈/p〉
〈p〉〈b〉Source:〈/b〉 Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 211〈/p〉
〈p〉Author(s): Tao Jia, Zhi-Hang Chen, Peng Guo, Junping Yu〈/p〉
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〈h5〉Abstract〈/h5〉
〈div〉〈p〉Two cationic δ,δ′‑diazacarbazoles, 1‑Methyl‑5〈em〉H〈/em〉‑pyrrolo[3,2‑〈em〉b〈/em〉:4,5‑〈em〉b〈/em〉′]dipyridinium iodide (〈strong〉MPDPI〈/strong〉) and 1,5‑Dimethyl‑5〈em〉H〈/em〉‑pyrrolo[3,2‑〈em〉b〈/em〉:4,5‑〈em〉b〈/em〉′]dipyridinium iodide (〈strong〉DPDPI)〈/strong〉, were devised and synthesized. Through characterizations of the interactions between DNA and the two δ,δ′‑diazacarbazoles by various spectroscopy means, the strong interactions between the two compounds and double-strand DNA have been observed and the interaction types and mechanisms were explored. UV–Vis and fluorescent data have shown the big changes of DNA in the presence of either of the two compounds, demonstrating that both of the δ,δ′‑diazacarbazoles can bind to DNA tightly, and high ionic strength decreased the intercalative interactions. The UV–Vis and fluorescence of dsDNA in the presence of 〈strong〉DPDPI〈/strong〉 showed more profound changes than those in the presence of 〈strong〉MPDPI〈/strong〉, due to 〈img src="https://sdfestaticassets-eu-west-1.sciencedirectassets.com/shared-assets/16/entities/sbnd"〉CH〈sub〉3〈/sub〉 (in the structure of 〈strong〉DPDPI〈/strong〉) taking place of H (in the structure of 〈strong〉MPDPI〈/strong〉) at the position of 5‑NH. And the circular dichroism (CD) spectra of CT-DNA and atomic force microscopy (AFM) results indicated more compacted conformation of DNA in the presence of 〈strong〉DPDPI〈/strong〉 than 〈strong〉MPDPI〈/strong〉, implying that 〈strong〉DPDPI〈/strong〉 has a more significant effect on DNA conformations than 〈strong〉MPDPI〈/strong〉. Most interestingly, fluorescence enhancement of cationic δ,δ′‑diazacarbazoles occurred in the presence of DNA. With ionic strength increasing, the intercalative interactions between δ,δ′‑diazacarbazoles and DNA were weakened, but δ,δ′‑diazacarbazoles-DNA complexes showed enhanced fluorescence, which indicated that there are other interactions present at high ionic strength. Furthermore, laser confocal fluorescence microscopy results proved that 〈strong〉DPDPI〈/strong〉 was membrane-permeable and stained living cells.〈/p〉〈/div〉
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〈h5〉Graphical Abstract〈/h5〉
〈div〉〈p〉〈figure〉〈img src="https://ars.els-cdn.com/content/image/1-s2.0-S1386142518310758-ga1.jpg" width="301" alt="Unlabelled Image" title="Unlabelled Image"〉〈/figure〉〈/p〉〈/div〉
〈/div〉
Print ISSN:
1386-1425
Electronic ISSN:
1873-3557
Topics:
Chemistry and Pharmacology
,
Physics
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