School of Chemistry, Centre of Synthesis and Chemical Biology, and Trinity Biomedical Science Institute, University of Dublin, Trinity College Dublin, Dublin 2, Ireland.
Org Biomol Chem. 2013 Sep 14;11(34):5642-55. doi: 10.1039/c3ob40370j.
The synthesis and characterisation of two cationic pyridinium based 4-amino-1,8-naphthalimide derivatives (2 and 3) are described and compared to those of compound 1. The photophysical properties of 2 and 3 are shown to vary greatly with the solvent polarity and H-bonding ability. The dimethylamino substitution in 3 results in a weak quantum yield of fluorescence emission due to faster non-radiative deactivation of the excited singlet state than that seen for 2. As with 1, the fluorescence of 2 was found to be enhanced in its 1 : 1 complex with 5'-adenosine-monophosphate (5'-AMP) while it was partially quenched in its complex with 5'-guanosine-monophosphate (5'-GMP). In contrast, the fluorescence of 3 was enhanced ('switched on') in the presence of both adenine and guanine rich sequences. Linear and circular dichroism studies showed that each of 1, 2 and 3 binds to double-stranded DNA by intercalation. However, 2 and 3 do not show the preference for AT-rich DNA observed for 1. Comparative fluorescence studies with double stranded DNA show that the emission of was 16 times enhanced in its DNA bound form, suggesting potential use of this structure as a spectroscopic probe for studying nucleic acid structure.
描述并比较了两种基于阳离子吡啶鎓的 4-氨基-1,8-萘酰亚胺衍生物（2 和 3）的合成和特性。结果表明，2 和 3 的光物理性质随溶剂极性和氢键能力的变化而有很大的差异。3 中的二甲氨基取代导致荧光发射量子产率较弱，因为激发单重态的非辐射去活速度比 2 快。与 1 一样，2 的荧光在与 5'-单磷酸腺苷（5'-AMP）的 1:1 复合物中增强，而在与 5'-单磷酸鸟苷（5'-GMP）的复合物中部分猝灭。相比之下，在存在富含腺嘌呤和鸟嘌呤的序列时，3 的荧光增强（“开启”）。线性和圆二色性研究表明，1、2 和 3 都通过嵌入与双链 DNA 结合。然而，2 和 3 没有表现出对 1 观察到的富含 AT 的 DNA 的偏好。与双链 DNA 的比较荧光研究表明，在其 DNA 结合形式下，1 的发射增强了 16 倍，这表明该结构可能作为研究核酸结构的光谱探针具有潜在用途。
