Institute of Physical Organic Chemistry, Surganova 13, 220072 Minsk, Belarus.
J Org Chem. 2012 Jan 20;77(2):977-84. doi: 10.1021/jo202229t. Epub 2011 Dec 23.
A convenient procedure for the preparation of the fluorescent dye 4',5'-dichloro-2',7'-dimethoxy-5(6)-carboxyfluorescein (JOE) is reported; the overall yield achieved starting from isovanillin is 10 times higher (40% vs 4%) compared to the known procedure. Isomers (5- and 6-) are easily chromatographically separable as pentafluorophenyl esters of 3',6'-O-bis(cyclohexylcarbonyl) derivatives. Four non-nucleoside JOE phosphoramidites based on 5- and 6-isomers and flexible 6-aminohexanol (AH) or rigid 4-trans-aminocyclohexanol (ACH) linkers have been prepared and used for oligonucleotide labeling. Spectral and photophysical properties of 5'-JOE-modified oligonucleotides have been studied. Fluorescence quantum yield of the dye correlates with the nature of the linker (rigid vs flexible) and with the presence of dG nucleosides in close proximity to a JOE residue.
报告了一种荧光染料 4',5'-二氯-2',7'-二甲氧基-5(6)-羧基荧光素（JOE）的简便制备方法；与已知方法相比，从异香草醛开始，总收率提高了 10 倍（40%对 4%）。异构体（5-和 6-）作为 3'，6'-O-双（环己基羰基）衍生物的五氟苯基酯很容易通过色谱法分离。基于 5-和 6-异构体和柔性 6-氨基己醇（AH）或刚性 4-反式-氨基环己醇（ACH）接头的 4 种非核苷 JOE 膦酸酯已被制备并用于寡核苷酸标记。研究了 5'-JOE 修饰的寡核苷酸的光谱和光物理性质。染料的荧光量子产率与接头的性质（刚性与柔性）以及在靠近 JOE 残基的位置存在 dG 核苷有关。
