Yamamoto N, Okamoto T, Kawaguchi M
Canon Research Center, Canon Inc., Kanagawa, Japan.
Nucleic Acids Symp Ser. 1993(29):83-4.
Discovery is reported of novel intercalators without fused ring systems, pyrylium and thiopyrylium salt. 2-Methyl-4,6-bis-(N,N-dimethylaminophenyl) pyrylium salt 1 (Fig. 1) is, in particular, virtually non-fluorescent in aqueous solution, but form highly fluorescent complexes with double-stranded DNA (dsDNA), which yield more than 400 fold fluorescence enhancement at the peak emission. We report the synthesis, absorption and fluorescence properties of 1 and its thiopyrylium derivative 2 in comparison with other pyrylium 3, thiopyrylium 4 dyes and typical intercalator, ethidium bromide(EB). Compound 1 shows the absorption maximum at 540 nm and the red shift (about 40 nm) in the presence of dsDNA in similar to EB. The enhancement of fluorescence emission excited by visible light is extremely sensitive to the concentration of dsDNA comparing to that of EB. The thiopyrylium salt 2 with absorption maximum at 575 nm shows the similar profile in the absorption spectral shift and fluorescence enhancement to that of 1, when the dye binds to dsDNA.
据报道发现了没有稠环系统的新型嵌入剂——吡喃鎓盐和噻吩吡喃鎓盐。特别是2-甲基-4,6-双-（N，N-二甲基氨基苯基）吡喃鎓盐1（图1），在水溶液中几乎不发荧光，但能与双链DNA（dsDNA）形成高荧光复合物，在峰值发射处产生超过400倍的荧光增强。我们报道了1及其噻吩吡喃鎓衍生物2与其他吡喃鎓染料3、噻吩吡喃鎓染料4和典型嵌入剂溴化乙锭（EB）相比的合成、吸收和荧光性质。化合物1在540nm处有最大吸收，在存在dsDNA时出现红移（约40nm），这与EB相似。与EB相比，可见光激发的荧光发射增强对dsDNA的浓度极其敏感。最大吸收波长在575nm的噻吩吡喃鎓盐2在染料与dsDNA结合时，在吸收光谱位移和荧光增强方面表现出与1相似的特征。
