Oligonucleotide probes labeled with pyrene pairs that form excimers have a number of applications in hybridization analysis of nucleic acids. A long excited state lifetime, large Stokes shift, and chemical stability make pyrene excimer an attractive fluorescent label. Here we report synthesis of chiral phosphoramidite building blocks based on (R)-4-amino-2,2-dimethylbutane-1,3-diol, easily available from an inexpensive d-(−)-pantolactone. 1-Pyreneacetamide, 1-pyrenecarboxamide, and DABCYL derivatives have been used in preparation of molecular beacon (MB) probes labeled with one or two pyrenes/quenchers. We observed significant difference in the excimer emission maxima (475–510 nm; Stokes shifts 125–160 nm or 7520–8960 cm^–1) and excimer/monomer ratio (from 0.5 to 5.9) in fluorescence spectra depending on the structure and position of monomers in the pyrene pair. The pyrene excimer formed by two rigid 1-pyrenecarboxamide residues showed the brightest emission. This is consistent with molecular dynamics data on excimer stability. Increase of the excimer fluorescence for MBs after hybridization with DNA was up to 24-fold.

中文翻译：

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通过改变单体结构对分子信标中P准分子荧光的微调

用pyr对标记的寡核苷酸探针形成受激准分子，在核酸杂交分析中有许多应用。较长的激发态寿命，大的斯托克斯位移和化学稳定性使pyr准分子成为有吸引力的荧光标记。在这里，我们报告了基于（R）-4-氨基-2,2-二甲基丁烷-1,3-二醇的手性亚磷酰胺结构单元的合成，可从便宜的d -（-）-泛内酯轻松获得。1-P乙酰胺，1-py羧酰胺和DABCYL衍生物已用于制备标有一个或两个pyr /猝灭剂的分子信标（MB）探针。我们观察到准分子发射最大值（475–510 nm；斯托克斯位移125–160 nm或7520–8960 cm ^–1）存在显着差异）和荧光光谱中的准分子/单体比（0.5至5.9），具体取决于the对中单体的结构和位置。由两个刚性的1 -re碳酰胺残基形成的pyr准分子显示最亮的发射光。这与关于准分子稳定性的分子动力学数据一致。与DNA杂交后，MBs的准分子荧光增加高达24倍。