手性固定相Chirex3001对安息香和联萘酚及其类似物的分子识别

利用分子力学方法,建立了苯基甘氨酸型手性固定相Chirex3001的简化模型,并探讨了手性固定相Chirex3001与安息香和联萘酚及其类似物的识别机制.模拟结果表明,固定相主体与手性客体分子识别作用的推动力主要来自于它们之间的π-π堆积、氢键和范德华等作用.主体与(S)-构型的客体1～3结合能力强于(R)-构型的客体,而对于客体4～6,则是与(R)-构型的结合强于(S)-构型,这与高效液相色谱拆分实验结果相符.客体1～3对映体在Chirex3001柱上的分离因子分别为1.02,1.04和1.11,(R)-构型先被洗脱;客体4～6对映体的分离因子分别为1.23,1.26和1.09,(S)-构型先被洗脱

Molecular recognition of benzoin and bi-beta-naphthol analogues by Chirex 3001-based chiral stationary phase

The simplified model of (R)-phenylglycine based chiral stationary phase (Chirex 3001) was built to investigate the process of chiral recognition of benzoin and bi-beta-naphthol and their analogues by molecular mechanics methods. The results showed that the driving force of chiral recognition came from the pi-pi stacking, hydrogen bond and van der Waals interactions between the host and the guest molecule. The host preferred to bind with S-enantiomers of benzoin and its analogues 1 similar to 3, and preferred to bind with R-enantiomers of bi-beta-naphthol and its analogues 4 similar to 6. This was consistent with the HPLC experimental results. The separation factors were 1.02, 1.04 and 1.11 respectively for compounds 1 similar to 3 when n-hexane/1,2-dichloroethane/ethanol (V : V : V=83.5 : 15 : 1.5) was used as mobile phase, and the R-enantiomers were eluted first. The separation factors were 1.23, 1.26 and 1.11 respectively when n-hexane/chloroform/ethanol (V : V : V=78.5 : 20 : 1.5) was used as mobile phase, and the S-enantiomers were eluted first

Fast detection of kanamycin in milk by protamine-aptamer-gold nanotechnology

基于聚阳离子鱼精蛋白与带负电的核酸适配体以及金纳米粒子之间的静电作用,发展了一种生物纳米检测技术,用于卡那霉素的检测;优化了缓冲溶液中阳离子、鱼精蛋白以及核酸适配体浓度,结果表明在20 mmol/L Na+、1 mmol/L Mg2+、2 mg/L鱼精蛋白、100 nmol/L核酸适配体条件下,卡那霉素在55 000 nmol/L范围内与金纳米粒子的吸光度比值呈现良好的线性关系,相关系数（R2）为0.992 8,方法的检出限为0.53 nmol/L。在此实验条件下,检测了牛奶中卡那霉素的含量,回收率为96%98%,相对标准偏差为1.5%3.2%。该方法选择性高,灵敏度好,线性范围广,显示出其应用于食品中卡那霉素检测的优势。&nbsp

Enantioseparation of amino acid derivatives with a cellulose-based chiral stationary phase

Five structurally related amino acid derivatives were enantioseparated by HPLC with a commercially available chiral stationary phase, Chiralcel OD-H. The chromatographic experiments were performed in the normal phase mode. n-Hexane/polar alcohol was used as mobile phase. Excellent baseline enantioseparations could be obtained for all these solutes. The effects of the concentration of polar alcohol and the column temperature on the retentions and enantioseparations were studied in detail. From the van't Hoff plots the corresponding apparent thermodynamic parameters were derived. Mechanism aspects of chiral recognition were discussed based on the relationship between the thermodynamic parameters and the structures of the solutes. It was found that the substituent of the phenyl group on the residual group of the amino acid derivatives was close relevant to thermodynamic origin of enantioseparation. Much better enthalpy-entropy compensation effect was obtained by plotting the differential, rather than the original, thermodynamic parameters