The syntheses of a variety of 1,3,5-triazinebenzimidazoles obtained by the cyclocondensafion reaction of 2-guanidinobenzimidazole with a series of meta-substituted benzaldehydes were reported. The prepared compounds w...The syntheses of a variety of 1,3,5-triazinebenzimidazoles obtained by the cyclocondensafion reaction of 2-guanidinobenzimidazole with a series of meta-substituted benzaldehydes were reported. The prepared compounds were fully characterized by IR and NMR spectroscopies. Based on the density functional theory（DFT） calculations method, quantum chemical calculations were performed by Gaussian 09 set of programs. All possible transition states, reactants and products were fully optimized at the hybrid density functional B3LYP level using the 6-311＋G（d,p）. The geometries of five possible tautomers of 2-amino-4-aryl[1,3,5]triazino[1,2-a]benzimidazoles were optimized in ethanol, using conductor like polarizable confinuum（CPCM） in the gas phase. The energetic diagrams of tautomeric equilibrium showed that form A is the most stable tautomer which proved to be in accordance with the X-ray diffraction structure analysis. In order to interpret the reaction mechanism, the chemical reactivity was studied using local and global reactivity indexes.展开更多
芝麻是八大类食物过敏原之一,快速准确识别芝麻过敏原对预防其过敏有重要意义。核酸适配体可以高效识别靶标过敏原,在过敏原检测中有良好的应用前景。为了获得芝麻主要过敏原Ses i 2的特异性核酸适体,本研究以Ses i 2为靶标,通过磁珠筛...芝麻是八大类食物过敏原之一,快速准确识别芝麻过敏原对预防其过敏有重要意义。核酸适配体可以高效识别靶标过敏原,在过敏原检测中有良好的应用前景。为了获得芝麻主要过敏原Ses i 2的特异性核酸适体,本研究以Ses i 2为靶标,通过磁珠筛选法(磁珠-SELEX)开展10轮筛选,经由高通量测序获得6条候补序列(S1~S6),并进行家族性、同源性分析及二级结构预测。结果表明,6条候选核酸适体的重复率可达46.38%,其自由能在-9.02到-2.47 kcal·moL^(-1)之间,根据自由能能量稳定原则,S1和S5吉布斯自由能最低最稳定,分别为-6.70和-9.02 kcal·moL^(-1)。利用ELISA试验进行亲和力测试,结果表明核酸适体S1和S2的亲和能力较强,S1:KD=67.02 nmol·L^(-1),R2=0.925 8,S2:KD=97.65 nmol·L^(-1),R2=0.795 1。核酸适体S1与过敏原Ses i 2的结合力和其他过敏原蛋白相比有显著差异,可视为具有特异性。本研究最终获得一条兼具良好亲和力和特异性的核酸适体S1,为芝麻过敏原快速检测提供了技术支撑。展开更多
文摘The syntheses of a variety of 1,3,5-triazinebenzimidazoles obtained by the cyclocondensafion reaction of 2-guanidinobenzimidazole with a series of meta-substituted benzaldehydes were reported. The prepared compounds were fully characterized by IR and NMR spectroscopies. Based on the density functional theory（DFT） calculations method, quantum chemical calculations were performed by Gaussian 09 set of programs. All possible transition states, reactants and products were fully optimized at the hybrid density functional B3LYP level using the 6-311＋G（d,p）. The geometries of five possible tautomers of 2-amino-4-aryl[1,3,5]triazino[1,2-a]benzimidazoles were optimized in ethanol, using conductor like polarizable confinuum（CPCM） in the gas phase. The energetic diagrams of tautomeric equilibrium showed that form A is the most stable tautomer which proved to be in accordance with the X-ray diffraction structure analysis. In order to interpret the reaction mechanism, the chemical reactivity was studied using local and global reactivity indexes.
文摘芝麻是八大类食物过敏原之一,快速准确识别芝麻过敏原对预防其过敏有重要意义。核酸适配体可以高效识别靶标过敏原,在过敏原检测中有良好的应用前景。为了获得芝麻主要过敏原Ses i 2的特异性核酸适体,本研究以Ses i 2为靶标,通过磁珠筛选法(磁珠-SELEX)开展10轮筛选,经由高通量测序获得6条候补序列(S1~S6),并进行家族性、同源性分析及二级结构预测。结果表明,6条候选核酸适体的重复率可达46.38%,其自由能在-9.02到-2.47 kcal·moL^(-1)之间,根据自由能能量稳定原则,S1和S5吉布斯自由能最低最稳定,分别为-6.70和-9.02 kcal·moL^(-1)。利用ELISA试验进行亲和力测试,结果表明核酸适体S1和S2的亲和能力较强,S1:KD=67.02 nmol·L^(-1),R2=0.925 8,S2:KD=97.65 nmol·L^(-1),R2=0.795 1。核酸适体S1与过敏原Ses i 2的结合力和其他过敏原蛋白相比有显著差异,可视为具有特异性。本研究最终获得一条兼具良好亲和力和特异性的核酸适体S1,为芝麻过敏原快速检测提供了技术支撑。
