首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
青霉胺对映体的毛细管电泳手性分离及应用研究   总被引:7,自引:1,他引:6  
何敏  赵书林  陈洁 《分析化学》2006,34(5):655-658
建立了一种青霉胺对映体的毛细管电泳手性分离方法。采用2,4-二硝基氯苯作为青霉胺的衍生试剂,以磺化-β-环糊精(S-β-CD)作为手性选择剂,50mmol/LpH9.5的硼砂缓冲溶液作为电泳缓冲液,在14min内实现了青霉胺对映体的毛细管电泳手性拆分,分离度达3.7。本文还考察了在大量D-青霉胺存在下,测定微量L-青霉胺的可能性。当D-青霉胺中,L-青霉胺的含量在0.3%~2.0%范围内时,其浓度与吸光度之间呈现良好的线性关系(r=0.9995),对D-青霉胺药片进行光学纯度分析,获得了满意的结果。  相似文献   

2.
以L-多巴为测定目标, 以天然芳香氨基酸为替代样品, 建立了以非样品α-羟基酸为手性配体, 以铜和镍等二价金属为中心离子的手性配体交换毛细管电泳新方法. 当弱配位的α-羟基酸与中心离子的摩尔比大于6∶1时, 所建立的方法即可实现对D,L-氨基酸和D,L-多巴的基线分离, 可用于口服多巴药片含量的测定, 检测出质量分数为0.5%的异构体杂质, 其定量的线性范围是0.025~2.5 mmol/L, 回收率为96.3%. 据此方法测得某商品药片的实际含量(质量分数)为标称值的(97.33±0.70)%.  相似文献   

3.
欧婉露  李玉娟  石冬冬  屈锋 《色谱》2015,(2):152-157
藤黄酸(gambogic acid,GA)等环氧杂蒽酮类化合物的水溶性差,可通过非水毛细管电泳(non-aqueous capillary electrophoresis,NACE)分析。本文系统地考察了添加20%~60%(v/v)的甲醇或乙腈的运行电解质溶液对藤黄提取液中藤黄酸分离的影响。比较了不同的运行电解质溶液、运行电解质溶液浓度、pH、添加剂β-环糊精的浓度、分离温度及分离电压的影响,建立了测定藤黄药材中藤黄酸含量的非水毛细管电泳方法。在40%乙腈、10mmol/Lβ-环糊精、20 mmol/L四硼酸钠(pH 9.86)为运行电解质溶液、分离电压为10 kV、分离温度为30℃、检测波长为280 nm的条件下进行测定。结果表明,藤黄酸在2~2 000 mg/L范围内线性关系良好,相关系数为0.999 6,检出限(S/N=3)为2 mg/L。将本方法应用于越南、泰国、缅甸、印度4个产地的藤黄药材中藤黄酸的含量测定,测得含量为1.67~472.40 mg/g(相对标准偏差(RSD)为1.12%~2.60%),其中越南产藤黄中藤黄酸含量低,其他产地藤黄中藤黄酸的含量高。实际藤黄样品中藤黄酸的加标回收率为95.2%~105.6%。非水毛细管电泳方法简单、快速、重现性好,可用于藤黄药材中藤黄酸的含量测定。  相似文献   

4.
建立了毛细管区带电泳手性拆分α-萘基缩水甘油醚对映体的方法.考察了不同手性拆分试剂对手性选择性的影响,实验结果表明,20 mmol/L H3PO4-三乙醇胺(pH 2.5)、2%(w/V)HS-β-CD、毛细管温度20 ℃、运行电压-18 kV为最佳分离条件,在该分离条件下α-萘基缩水甘油醚对映体实现基线分离.方法简便、准确,可用于α-萘基缩水甘油醚的手性拆分和对映体过量值(ee,%)测定.  相似文献   

5.
毛细管电泳/非接触式电导法分离检测氧氟沙星对映体   总被引:3,自引:1,他引:2  
采用毛细管电泳-电容耦合非接触式电导(CE-C4D),以20 mmol/L HAc + 6 mmol/L NaAc+12 mg/L羟丙基甲基纤维素(HPMC)+35 mmol/L羟丙基-β-环糊精(HP-β-CD)为电泳运行液,在熔融石英毛细管柱(45 cm×50 μm i.d.,有效长度 40 cm)中,正高压分离,手性药物氧氟沙星对映体获得良好的基线分离,线性检测范围为0.8~40 mg/L,检出限为0.3 mg/L.考察了电泳运行液组成、二元手性选择剂(HP-β-CD和HPMC)的浓度、进样方式和样品基质等对灵敏度和分离度的影响.本方法应用于市售外消旋和左旋氧氟沙星片剂中对映体的分离测定.  相似文献   

6.
以高磺化-β-环糊精为毛细管电泳手性选择剂,建立了有效分离7种手性芳香仲醇对映体的方法.在20 mmol/L H3PO4-三乙醇胺为背景电解质(pH 2.5),6%(m/V) 高磺化-β-环糊精为手性选择剂(S-β-CD),柱温20 ℃,操作电压-15 kV,检测波长214 nm等优化条件下,所有芳香仲醇对映体均实现基线分离.以本方法测定了7种芳香酮不对称氢转移反应产物7种手性芳香仲醇的百分对映体过量值(% ee),其测定结果与高效液相色谱、气相色谱测定结果完全一致.本方法可以用于手性芳香仲醇光学纯度的测定.  相似文献   

7.
胶束电动毛细管电泳法测定β-内酰胺类抗生素   总被引:4,自引:0,他引:4  
采用胶束电动毛细管电泳(MEKC)法测定多种β-内酰胺类抗生素及舒巴坦的含量。电泳运行缓冲液为20 mmol/L硼砂缓冲液(pH9.5),十二烷基硫酸钠(SDS)38 mmol/L。8种药物在15m in内达到基线分离。选择苯巴比妥作为内标,各组分浓度在50~600 mg/L范围内呈良好线性关系,相关系数为0.9932~0.9993;检出限4.8~26 mg/L;进样精密度RSD 3.0%~5.6%;对头孢哌酮-舒巴坦制剂进行含量测定,回收率为100%~106%,含量测定结果与HPLC方法所得结果没有显著性差异。  相似文献   

8.
史雪岩  梁沛  宋敦伦  高希武  傅若农 《分析化学》2004,32(11):1421-1425
以聚合-β-环糊精作为毛细管区带电泳手性选择剂,成功分离了2-苯氧丙酸(PPA)、顺式-功夫菊酸(cis-PA)、1-苯基-2-(对甲苯基)乙胺(PTE)和1-苯基-2-(对甲氧基苯基)乙胺(PME)4种光学活性农药中间体的对映体。考察了不同手性选择剂及其浓度、背景电解质的pH等操作条件对分离的影响。结果表明,在12kV操作电压下、30mmol/Ltris-HCl背景电解质中,用14g/L聚合-β-CD作为手性选择剂,PPA和cis-PA对映体在pH6.0时,PIE和PME对映体分别在pH2.5和pH3.0时可以被较好分离。在优化的分离条件下,用聚合-β-CD作毛细管区带电泳手性选择剂分离PIE对映体的分离度为1.513,成功测定了两种旋光性PIE的对映体过量值。  相似文献   

9.
 首次使用大环内酯类抗生素红霉素作为毛细管电泳手性选择剂,采用未涂层石英毛细管分离了两种联苯双酯类保肝药物。实验考察了背景电解质中磷酸盐缓冲液的pH值及浓度、分离电压及温度、红霉素浓度、有机添加剂甲醇含量对手性分离的影响。实验结果表明,磷酸盐浓度为50 mmol/L(pH 5.0)、分离电压为-20 kV、红霉素浓度为30 mmol/L、甲醇的体积分数为50%是最佳分离条件。同时证明红霉素可以作为手性选择剂用于毛细管电泳手性分离中。  相似文献   

10.
基于非手性离子液体的毛细管电泳法拆分3种手性药物   总被引:1,自引:1,他引:0  
夏陈  陈志涛  夏之宁 《色谱》2008,26(6):677-681
建立了以非手性离子液体1-正丁基-3-甲基咪唑氯([BMIM]Cl)为手性分离的添加剂、β-环糊精作为手性选择剂的毛细管区带电泳(CZE)分离扑尔敏、氯霉素前体和氧氟沙星3种对映体的方法,并与未添加[BMIM]Cl的CZE分离情况进行了对比研究。发现[BMIM]Cl对手性药物的拆分有协同作用,不仅能够增加对映体的分离度,还能有效地抑制毛细管内壁对样品分子的吸附作用,改善峰形。采用离子液体辅助手性选择剂(尤其是环糊精)的CZE改进方法,为其他毛细管电泳难以分离的手性药物的分离分析提供了新的方法。  相似文献   

11.
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.  相似文献   

12.
KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.  相似文献   

13.
The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.  相似文献   

14.
Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.  相似文献   

15.
A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.  相似文献   

16.
The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp3)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp2)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp2)?H and aliphatic 1,5- and 1,6-C(sp3)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp3)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp2)?H insertion.  相似文献   

17.
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.  相似文献   

18.
An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.  相似文献   

19.
20.
N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号