A general synthetic strategy for the attachment of Nile red through a rigid acetylene linker to 2′-deoxyuridine and 7-deaza-2′-deoxyadenosine using Sonogashira coupling is demonstrated. Protection of either 5′-OH or N-7 of the nucleosides increased the yields of the cross-couplings significantly. Both Nile red modified 2′-deoxyuridine and 7-deaza-2′-deoxyadenosine as well as their derivatives exhibit excellent fluorescence quantum efficiencies and positive solvatochromism. The incorporation of the Nile red modified 2′-deoxyuridine into oligonucleotides yields bright fluorescent probes with maintained canonical base pairing in DNA.
本研究展示了利用 Sonogashira 偶联法通过刚性
乙炔连接体将
尼罗红连接到 2′-脱氧
尿苷和 7-脱氮-2′-脱氧
腺苷的一般合成策略。对核苷的 5′-OH 或 N-7 进行保护可显著提高交叉耦合的产率。
尼罗红修饰的 2′-脱氧
尿苷和 7-脱氮-2′-脱氧
腺苷及其衍
生物都表现出优异的荧光量子效率和正溶色性。将尼罗河红修饰的 2′-脱氧
尿苷掺入寡核苷酸中可产生明亮的荧光探针,并保持 DNA 中典型的碱基配对。