最近,我们报道了基于氧杂蒽酮(CDXs)的手性衍生物的液相色谱(LC)的新手性固定相(CSP)的开发。基于最有前途的CDX选择器,成功地从合适的功能化小分子(包括one吨酮和二苯甲酮衍生物)制备了12种新的CSP。将包含一个,两个,三个或四个手性部分的手性选择剂共价键合到色谱载体上,并进一步填充到LC不锈钢柱(150×2.1 mm ID)中。使用不同种类的手性化合物通过LC评估了新CSP的对映选择性。在评估新的CSP时观察到了对映体分离某些CDX的特异性。除了,通过使用分子对接方法的计算研究对手性识别机理进行了评估,这与色谱参数相符。X射线分析用于建立手性选择器3D结构。
最近,我们报道了基于氧杂蒽酮(CDXs)的手性衍生物的液相色谱(LC)的新手性固定相(CSP)的开发。基于最有前途的CDX选择器,成功地从合适的功能化小分子(包括one吨酮和二苯甲酮衍生物)制备了12种新的CSP。将包含一个,两个,三个或四个手性部分的手性选择剂共价键合到色谱载体上,并进一步填充到LC不锈钢柱(150×2.1 mm ID)中。使用不同种类的手性化合物通过LC评估了新CSP的对映选择性。在评估新的CSP时观察到了对映体分离某些CDX的特异性。除了,通过使用分子对接方法的计算研究对手性识别机理进行了评估,这与色谱参数相符。X射线分析用于建立手性选择器3D结构。
was performed by moleculardocking approach, which are in accordance with the chromatographic parameters. The nature and number of chiral moieties in the central aromatic scaffold of either xanthone or benzophenone derivatives are proved to be crucial for enantiorecognition. The evaluation of the growth inhibition of human tumor cell lines revealed that (S,S)‐(+)‐5 was the most potent compound, with
报道了包含一个或多个手性部分的合成呫吨酮和二苯甲酮衍生物的液相色谱对映体分离和对映体纯度的测定。对于包含与立体中心相连的芳香环的化合物的对映体混合物,在 ( S , S )-Whelk-O1 手性固定相 (CSP) 中观察到高对映选择性和分辨率,α 值范围为 1.35 至 4.15, Rs值范围为 2.22 至 13.87。在所有测试的对映体混合物中,包含位于呫吨酮支架中的三个手性部分的对映体混合物给出了最好的色谱结果。包含连接到立体中心的烷基链的对映体在 Lux® Celulllose-2 CSP 上进行对映分离。对于这两种 CSP,洗脱均以极性有机模式进行。对映体比率(er)值始终高于99%。此外,通过分子对接方法对( S , S )-Whelk-O1 CSP 的手性识别机制进行了评估,该方法与色谱参数一致。呫吨酮或二苯甲酮衍生物的中心芳香骨架中手性部分的性质和数量被证明对于对映体识别
Potentiometric Titrations of Five Synthetic Tetraacids as Models for Indigenous C<sub>80</sub> Tetraacids
作者:Ola Sundman、Erland L. Nordgård、Brian Grimes、Johan Sjöblom
DOI:10.1021/la902326y
日期:2010.2.2
The acid/base properties, critical micelle concentrations (cmcs), and pH-dependent solubility of five synthetic tetraacids have been studied at several ionic strengths (20-600 mM NaCl) and in the pH range of 1.5-11 using high precision potentiometric titrations, tensiometer measurements, and UV spectroscopy, respectively. The Molecular weight of the tetraacids ranged between 478 and 983 g/mol. The potentiometric titration data was evaluated in terms of thermodynamic equilibrium models, developed in the light of relevant solubility data, Langmuir monolayer compressions and cmc of the different tetraacids. The results indicate that for two of the tetraacids, called BP5 and BP7, two chemical forms fully dominate the speciation of the monomers; the insoluble fully protonated form, and the soluble fully deprotonated form. The partly protonated species. only play a very minor role in the speciation of these tetraacids. For the other tetraacids the results are more complicated; for the smallest tetraacid, called BPI, all species seem to play important roles, and for the most hydrophobic, BP10, the formation of micelles and aggregates severely complicates the evaluation of the speciation. For the tetraaacid BP3 one of the partly deprotonated forms seems to be important, thus confirming the structure to properties relationship. In spite of the complicated micelle formation chemistry, and although not actually measured, the acid/base properties for the monomers of BP10 were interpreted by means of Surface charge densities of the micellar aggregates. The modeling indicates an increase of the aggregation number of the micelle upon acidification, a result of formation of mixed micelles incorporating the fully protonated and deprotonated species. An intrinsic pK(a) of 5.4. for BP5 was used to model the monomer pK(a) of BP10, and corresponded well with a monolayer acidity constant pK(a)(s) of 5.5 obtained from surface collapse pressures of Langmuir monolayers as a function of pH.