Synthesis o novel arylboronic acids and their analytical use as luminescent reagents

利用洛芬具有较强的荧光性和化学发光性，合成了四种新型的芳基硼酸，它们是洛芬及其类似物的衍生物。由于已知一些芳基硼酸可以增强鲁米诺-过氧化氢-辣根过氧化物酶（HRP） CL反应，我们首先评估了这些增强剂。其中，4-[4,5-二（2-吡啶基）- 1h -咪唑-2-基]苯硼酸（DPPA）是最有效的增强剂。添加DPPA后HRP的检出限为0.15 ng（约3.5 fmol），比未添加增强剂时提高了约180倍。利用DPPA延长发光时间的作用，将CL系统应用于硝基纤维素膜上HRP的照相检测。在优化CL反应条件后，只有0.1 ng的HRP在照相上可检测到。该方法成功地应用于抗人t细胞白血病i型病毒的western blot检测。其次，对芳基硼酸的FL和CL特性进行了研究，为开发二醇类化合物的FL探针或FL/CL标记试剂打下基础。4-（4,5-二苯基- 1h -咪唑-2-基）苯硼酸（DPA）具有较强的滤光性，而其他衍生物的滤光性较弱，但并非所有衍生物的滤光性都比洛芬强。虽然目前用薄层色谱法估计了DPA与某些二醇的反应，但还需要进一步的反应性研究和光谱研究。

Four kinds of novel arylboronic acids, which are the derivatives of lophine and its analogues, were synthesized based on the fact that lophine shows strong fluorescence (FL) and chemiluminescence (CL).Since some arylboronic acids are known to enhance the luminol-hydrogen peroxide-horseradish peroxidase (HRP) CL reaction, we evaluated those as enhancers at first. Among the compounds examined, 4-[4,5-di(2-pyridyl)-1H-imidazol-2-yl]phenyl boronic acid (DPPA) was found to be the most potent enhancer. The detection limit of HRP with DPPA was 0.15 ng (ca. 3.5 fmol) which was ca. 180 times better than that in the absence of the enhancer. By using DPPA with the effect of prolonging the light emission, the CL system was applied to the photographic detection of HRP on a nitrocellulose membrane. After optimizing the CL reaction conditions, as little as 0.1 ng of HRP was photographically detectable. This method was successfully applied to the western blotting assay of anti-human T-cell leukemia virus type-I.Next, FL and CL characteristics of the arylboronic acids were examined as fundamental studies on developing FL probes or FL/CL labeling reagents for diol compounds. 4-(4,5-Diphenyl-1H-imidazol-2-yl )phenylboronic acid (DPA) showed a stronger FL than lophine whereas the other derivatives had weaker FL. Stronger CL was not observed for all derivatives, compared to that of lophine. Although the reaction of DPA with some diols was estimated by TLC so far, further investigation on the reactivity and spectral studies will be required.