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以替考拉宁为手性选择剂制备了大环抗生素类手性固定相替考拉宁键合手性固定相(T-CSP),建立了T-CSP反相液相色谱直接拆分泮托拉唑钠对映体的方法。考察了流动相中有机改性剂的种类和比例、柱温以及流动相流速对拆分泮托拉唑钠对映体的影响。研究发现,用甲醇作有机改性剂比乙腈更有利于对映体的分离;在研究的温度范围内,随着柱温的升高,对映体的保留时间缩短,同时分离因子和分离度降低;在一定范围内降低流速有利于对映体的分离。采用T-CSP色谱柱(150 mm×4.6 mm i.d.,5 μm),以甲醇-水(体积比为35∶65)为流动相,在流速0.6 mL/min、检测波长290 nm、柱温20 ℃的条件下,泮托拉唑钠对映体获得了近于基线的分离,所建立的方法具有简便快速及重复性好等优点。 相似文献
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采用高效液相色谱法,以9-蒽醛为衍生试剂,在5种多糖衍生物的手性固定相(CSPs)上对几种α-氨基酸甲酯对映体进行了手性分离。色谱条件如下: 流动相为含3%~10%(v/v)异丙醇的正己烷溶液,流速为1.0 mL/min,检测波长为254 nm。结果表明,α-氨基酸甲酯-9-蒽醛亚胺衍生物在Chiralcel OD柱或Chiralcel OD-H柱上的手性分离结果优于其他CSPs,而且在Chiralcel OD柱或Chiralcel OD-H柱上全部得到了基线拆分(α=1.24~5.47, Rs=2.56~13.90), L-对映体在这两种色谱柱上的保留强于D-对映体。同时还考察了几种脂肪胺在5种多糖衍生物手性固定相上的对映体拆分效果,结果表明脂肪胺的9-蒽醛亚胺衍生物在Chiralcel OD柱或Chiralcel OD-H柱上的分离效果良好。该法可用于其他α-氨基酸酯和胺类化合物对映体的分析。 相似文献
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用大环抗生素替考拉宁手性固定相(TE CSP)分别与3,5-二甲基苯基异氰酸酯和苯基异氰酸酯反应得到了两种新型的高效液相色谱手性固定相----3,5-二甲基苯基异氰酸酯替考拉宁手性固定相(DMP-TE CSP)和苯基异氰酸酯替考拉宁手性固定相(Ph-TE CSP)。用十八个手性化合物在反相及极性流动相模式对这两种CSP的对映体分离能力进行了评价和比较。在反相流动相中,十二个化合物(包括八个氨基酸和四个非氨基酸化合物----对羟基苯甘氨酸,拉米夫定,醇酸和去甲羟安定)的对映体在这两种手性固定相上都获得了分离,大部分的溶质在DMP-TE上获得了更强的保留和稍好的手性分离效果。在极性流动相中,六个氨基醇类化合物在DMP-TE上获得了更强的保留,但它们在两种CSP上的选择因子几乎没有区别。对自制的替考拉宁衍生物手性固定相进行评价和比较,将有助于大环糖肽类抗生素手性固定相手性识别机理的研究。 相似文献
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由替考拉宁手性固定相(TE CSP)制备出了一种新型的高效液相色谱手性固定相: 间甲基苯基异氰酸酯替考拉宁手性固定相(TI-TE CSP). 在反相流动相中用7种氨基酸和3种非氨基酸化合物对这两种手性固定相的手性分离能力进行了评价和比较. 考察了有机添加剂的种类和浓度, 缓冲液的pH值等条件对10个手性化合物在两种CSP上手性分离的影响, 计算得出了溶质在两种CSP上的手性选择性自由能差值, 同时初步探讨了这些溶质在两种CSP上的手性识别机理. 实验数据表明, 氨基酸在TE上保留更强, 但在TI-TE上得到了更好的手性分离效果. 结果显示, 经间甲基苯基异氰酸酯衍生化后的替考拉宁CSP在反相流动相中的分离能力有所提高. 相似文献
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提出了洛美沙星对映体的高效液相色谱拆分方法。选用Chiralcel OJ手性柱,正己烷-异丁醇(90+10)的混合溶液为流动相,流量为0.6mL·min~(-1),柱温为30℃,检测波长为287nm。通过溶质计量置换保留模型和热力学理论对Chiralcel OJ手性柱拆分机理进行了探讨。结果表明:保留时间较短的洛美沙星对映体的lgI值和Z值均小于保留时间较长的对映体。在试验的温度范围内,用1nα对1/T作图,得到Van't Hoff曲线呈线性关系,焓变和熵变之差为负值,说明手性拆分过程为焓控过程。 相似文献
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采用高效液相色谱法,在自制的纤维素-三(3,5-二甲基苯基氨基甲酸酯)(ATEO-OD)、纤维素-三(4-甲基苯基氨基甲酸酯)(ATEO-OG)和纤维素-三(4-甲基苯基甲酸酯)(ATEO-OJ)3种手性柱上对16种不同结构的手性化合物进行了拆分和比较.试验结果表明:16个手性样品在这3种手性固定相上分别获得了不同程度的拆分,A TEO-OD对所分析样品具有更好的手性识别能力,ATEO-OG和ATEO-OJ的手性识别能力相当. 相似文献
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(S)-or (R)-2-Amino-4-phenylbutyric acid and (S)-or (R)-2-hydroxy-4-phenylbutyric acid and their ethyl esters are key chiral intermediates for the preparation of angiotensin converting enzyme inhibitors (ACEI) and other chiral drugs. Their practically asymmetric synthetic methods in large scale from four-carbon chiral pool, commercially available L-aspartic acid and L-malic acid, will be presented (as scheme). (S)-2-Amino-4-phenylbutyric acid and its ethyl ester hydrochloride were prepared from the easily available L-aspartic acid via activation by forming anhydride hydrochloride, Friedel-Crafts reaction with benzene, hydrogenolysis and esterification with ethanol in the presence of thionyl chloride in overall yield of 80% and 73.6% respectively with 99% ee. We first used amino acid anhydride hydrochloride as the acylating agent in Friedel-Crafts reaction without racemization. [1] 相似文献
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This note explains the relationship (as well as the absence of a relationship) between chiral space groups and chiral molecules (which have absolute configurations).For a chiral molecule,which must crystallize in a chiral space group,the outcome of the absolute configuration determination must be linked to some other properties of the chiral crystal such as its optical activity for the observation to the relevant. 相似文献
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XIAO Min LIU Xiao-juan HU Kai WU Li-min LI Yi LI Bao-zong YANG Yong-gang 《高等学校化学研究》2012,28(4):637-641
Chiral organic-inorganic hybrid silicas can be prepared via the self-assemblies of chiral surfactants and gelators as templates. However, the relationship between the chirality of the hybrid silica and the structure of the surfactant/gelator has not been systemically studied. Herein, a series of chiral low-molecular-weight amphiphiles(LMWAs) derived from L-valine was synthesized. Their alkyl chains were n-butadecyl, n-hexadecyl and n-octadecyl, respectively. They can form viscous liquids in pure water, and physical gels in tetrahydrofuran, cyclohexanone, acetonitrile, acetone, chlorobenzene and nitrobenzene. Chiral 1,4-phenylene-silicas were prepared viathe self-assemblies of these LMWAs as templates. With increasing the alkyl chain length, the 1,4-phenylene-silicas changed from short mesoporous nanorods to long nanotubes. The circular dichroism spectra of the 1,4-phenylene-silicas indicated that the long nanotubes exhibit the strongest chirality. 相似文献
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以手性冠醚为胶束毛细管电泳手性分离选择剂,对吉米沙星对映体药物的在线富集分离进行了研究.考察了阳离子表面活性剂十二烷基三甲基溴化铵浓度、运行缓冲溶液中有机添加剂含量和进样方式对对映体的富集和分离度的影响.使用未涂层毛细管柱(37 cm×51 μm,有效柱长30 cm),45 mmol/L Bis-Tris缓冲液+10 mmol/L十二烷基三甲基溴化铵(DTAB)+1 mmol/L手性冠醚+11%乙腈为运行缓冲溶液(pH=4.0),在紫外检测波长280 nm、运行电压-10 kV、电动进样条件下,对吉米沙星对映体进行在线推扫(sweeping)富集分离,在基线分离的前提下,富集倍数可达600~700倍.吉米沙星浓度为0.3 μmol/L时,两对映体峰高的相对标准偏差<4.0%(n=7).本方法为毛细管电泳在痕量对映体药物分析等方面的应用提供了新方法. 相似文献
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Yanqing Fan Jing He Lin Liu Guoqin Liu Shengzhu Guo Zhe Lian Xiaonan Li Weijie Guo Xuebo Chen Ying Wang Hua Jiang 《Angewandte Chemie (International ed. in English)》2023,62(28):e202304623
We report the synthesis and chiroptical properties of novel chiral carbon nanorings S p-/Rp-[12]PCPP containing a planar chiral [2.2]PCP unit, and demonstrate that S p-/Rp-[12]PCPP can not only host crown ether 18-Crown-6 to form ring-in-ring complexes with a binding constant 3.35×103 M−1, but also accommodate the complexes of 18-Crown-6 and S/R-protonated amines to form homochiral S @Sp -/ R @Rp - and heterochiral S @Rp -/ R @Sp - ternary complexes, displaying significantly larger binding constants of up to 3.31×105 M−1 depending on the chiral guests. Importantly, homochiral S @Sp -/ R @Rp - ternary complexes exhibit an enhanced CD signal, while the heterochiral S @Rp -/ R @Sp - ones have a constant CD signal compared with the chiral carbon nanorings, respectively, which suggests that homochiral S @Sp -/ R @Rp - ternary complexes display a highly narcissistic chiral self-recognition for S/R-protonated chiral amines, respectively. Finally, the chiral ternary complexes can be further applied to determine the ee values of chiral guests. The findings highlight a new application of carbon nanorings in supramolecular sensors, beyond the common recognition of π-conjugated molecules. 相似文献
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Dr. Pernille H. Poulsen Dr. Yang Li Dr. Vibeke H. Lauridsen Danny K. B. Jørgensen Dr. Teresa A. Palazzo Dr. Marta Meazza Prof. Dr. Karl Anker Jørgensen 《Angewandte Chemie (International ed. in English)》2018,57(33):10661-10665
A novel reaction that provides chiral allenes by amino catalytic activation of either aldehydes or α,β‐unsaturated aldehydes for reaction with alkynyl‐substituted enones is presented. The reaction forms a variety of trisubstituted allenes in high yields and with excellent stereoselectivities. The utility of the reaction concept is demonstrated by the synthesis of chiral furan derivatives in high yields and stereoselectivities. 相似文献