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1.
Summary Analytical HPLC methods using derivatized cellulose chiral stationary phases have been developed for separation of the enantiomers
of 25 racemic 4-aryl-7,7-dimethyl- or 1,77-trimethyl-1,2,3,4,5,6,7,8-octahydroquinazoline-2,5-diones, condensed derivatives
of dihydropyrimidines. The enantiomers of the compounds were resolved by normal-phase chromatography on silica-based cellulose
tris(3,5-dimethylphenylcarbamate) (Chiralcel OD) and amylose tris(3,5-dimethylphenylcarbamate) (Chiralpak AD) columns with
mobile phases consisting of mixtures ofn-hexane and an alcohol (2-propanol, ethanol, or methanol) in different proportions. The mobile phase and the chiral stationary
phase were varied to achieve the best resolution. The effect of the concentration of alcohol in the mobile phase was studied.
The resolution obtained on the two columns was complementary. 相似文献
2.
Enantioseparations in non-aqueous capillary electrochromatography using polysaccharide type chiral stationary phases 总被引:1,自引:0,他引:1
Enantioseparations of chiral compounds with different structures were studied in non-aqueous capillary electrochromatography (NAQ CEC). Three different polysaccharide derivatives, cellulose tris(3,5-dimethylphenylcarbamate) (Chiralcel OD), amylose tris(3,5-dimethylphenylcarbamate) (Chiralpak AD) and cellulose tris(4-methylbenzoate) (Chiralcel OJ) were used as chiral stationary phases (CSPs). Methanolic or ethanolic ammonium acetate solutions served as a mobile phase. The effect of the type of the CSP, the loading of the chiral selector on wide-pore aminopropyl derivatized silica gel and operational parameters such as apparent pH, applied voltage, etc. on the EOF and chromatographic characteristics (alpha, N, Rs) were studied. NAQ CEC represents a valuable alternative and an extension to chiral separations by HPLC with common-size columns as well as to capillary LC and CEC in aqueous buffers. 相似文献
3.
Lipka-Belloli E Len C Mackenzie G Ronco G Bonte JP Vaccher C 《Journal of chromatography. A》2002,943(1):91-100
This paper describes the separation of the four sets of stereoisomers of nucleoside analogs, new potential antiviral agents by direct analytical HPLC methods using derivatized cellulose and amylose chiral stationary phases. The resolution was made using normal-phase methodology with a mobile phase consisting of n-hexane-alcohol (ethanol or 2-propanol) in various percentages, and a silica-based cellulose tris-3,5-dimethylphenylcarbamate (Chiralcel OD-H), or tris-methylbenzoate (Chiralcel OJ) and a silica-based amylose tris-3,5-dimethylphenylcarbamate (Chiralpak AD) or tris-(S)-1-phenylethylcarbamate (Chiralpak AS). The effects of structural features on the extent of discrimination between the stereoisomers were examined through the retention, the selectivity and the resolution factors as well as the elution order. Baseline separation (Rs>1.5) was easily obtained in many cases. The resolution results were complementary between the different columns. 相似文献
4.
High-performance liquid chromatographic methods were developed for separation of the enantiomers of mirtazapine and its four process-related substances. The direct separations were achieved on chiral stationary phases containing amylose tris(3,5-dimethylphenylcarbamate) (Chiralpak AD-H), cellulose tris(3,5-dimethylphenylcarbamate) (Chiralcel OD-H) and cellulose tris(4-methylbenzoate) (Chiralcel OJ-H ). The experimental data were utilized to discuss the effects of the mobile phase composition, the nature of the alcoholic modifier and the specific structural features of the analytes on retention and separation. The elution sequence was determined under the optimized separation conditions. 相似文献
5.
Goossens JF Foulon C Villard AL Puy JY Lefebvre I Perigaud C Vaccher C Bonte JP 《Biomedical chromatography : BMC》2005,19(6):415-425
Analytical HPLC methods using derivatized cellulose and amylose chiral stationary phases used in normal and reversed-phase modes were developed for the diastereoisomeric separation of mononucleotide prodrugs (pronucleotides) of 3'-azido-2',3'-dideoxythymidine (AZT). The resolutions were performed with two silica-based celluloses using normal and reversed-phase methodologies: Tris-3,5-dimethylphenylcarbamate (Chiralcel OD-H and Chiracel OD-RH) and Tris-methylbenzoate (Chiralcel OJ and OJ-R). Two amyloses phases, Tris-3,5-dimethylphenylcarbamate (Chiralpak AD) and Tris-(S)-1-phenylethylcarbamate (Chiralpak AS), were used in normal-phase mode. Additionally, we developed separation using two stationary phases with immobilized cyclodextrins in reversed-phase and polar-organic modes. The mobile phase and the chiral stationary phase were varied to achieve the best resolution. Different types and concentration of aliphatic alcohols, acetonitrile or water in the mobile phase were also tested for the different separation modes. An optimal baseline separation (Rs > 1.5) was readily obtained with all silica-based celluloses and amyloses using a normal-phase methodology. The different columns gave complementary results in term of resolution. Limits of detection and quantification were 0.12-0.20 and 0.40-0.67 microm, respectively. This analytical method was applied in a preliminary study for the pronucleotide 2 quantification in cellular extract. 相似文献
6.
7.
选用不同的醇改性剂,在自制的直链淀粉-三(3,5-二甲基苯基氨基甲酸酯)(ADMPC)手性固定相上,对2种吲哚环衍生物对映体进行了手性拆分研究,并考察了样品的保留时间和立体选择性. 相似文献
8.
Armodafinil is a unique psychostimulant recently approved by the US Food and Drug Administration for the treatment of narcolepsy. The chromatographic resolution of its chiral intermediates including related substances in the total synthesis of armodafinil was studied on polysaccharide-based stationary phases, viz. cellulose tris-(3,5-dimethylphenylcarbamate) (Chiralcel OD-H) and amylose tris-(3,5-dimethylphenylcarbamate) (Chiralpak AD-H) by HPLC. The effects of 1-propanol, 2-propanol, ethanol, and trifluoroacetic acid added to the mobile phase and of column temperature on resolution were studied. A good separation was achieved on cellulose-based Chiralcel OD-H column compared to amylose-based Chiralpak AD-H. The effects of structural features of the solutes and solvents on discrimination between the enantiomers were examined. Baseline separation with R(s) >1.38 was obtained using a mobile phase containing n-hexane-ethanol-TFA (75:25:0.15 v/v/v). Detection was carried out at 225 nm with photodiode array detector while identification of enantiomers was accomplished by a polarimetric detector connected in series. The method was found to be suitable not only for process development of armodafinil but also for determination of the enantiomeric purity of bulk drugs and pharmaceuticals. 相似文献
9.
Lipka-Belloli E Glaçon V Mackenzie G Ewing D Len C Vaccher C Bonte JP 《Journal of chromatography. A》2002,972(2):211-219
We reported a method of determination of enantiomeric purity of the new potential antiviral agents by direct analytical HPLC. Those agents are nucleoside analogs, having one chiral center. They are synthesized as a single enantiomer (R or S) by an asymmetric pathway. The chiral stationary phases chosen are silica-based cellulose tris-3,5-dimethylphenylcarbamate (Chiralcel OD-H), or tris-methylbenzoate (Chiralcel OJ). Resolution was achieved using normal-phase chromatography with a mobile phase consisting of n-hexane-alcohol (ethanol or 2-propanol) in various percentages. Furthermore the effects of structural features on retention, selectivity and resolution, as well as on the elution order were thoroughly studied. Differences in the lipophilicity of the compounds were also examined. 相似文献
10.
Belloli E Foulon C Yous S Vaccher MP Bonte JP Vaccher C 《Journal of chromatography. A》2001,907(1-2):101-113
Analytical HPLC methods using derivatized cellulose chiral stationary phases were developed for the direct separation of the stereoisomers of disubstituted tetralin derivatives with two chiral centers, new agonist and antagonist ligands for melatonin receptors. The separations were made using normal-phase methodology with a mobile phase consisting of n-hexane-alcohol (methanol, ethanol, 1-propanol or 2-propanol) in various proportions, and a silica-based cellulose tris-3,5-dimethylphenylcarbamate (Chiralcel OD-H), or tris-methylbenzoate (Chiralcel OJ). The effects of concentration of various aliphatic alcohols in the mobile phase were studied. A better separation was achieved on cellulose carbamate phase compared with the cellulose ester phase. The effects of structural features of the solutes on the discrimination between the stereoisomers were examined. Baseline separation (Rs>1.5) was easily obtained in many cases. 相似文献
11.
Summary The separation of enantiomers of substituted cyclohexanecarboxamides, benzamides and chemical precursors of Rho-kinase inhibitors
was achieved using derivatized polysaccharide-based chiral stationary phases. Separations were by normal phase HPLC with a
mobile phase ofn-hexane-alcohol (methanol, ethanol or 2-propanol) in various proportions, and a silica-based cellulose tris-3,5-dimethylphenylcarbamate
(Chiralcel OD-H), tris-methylbenzoate (Chiralcel OJ), a silica-based amylose tris-(S)-1-phenylethylcarbamate (Chiralpak AS), or tris-3,5-dimethylphenylcarbamate (Chiralpak AD). The effects of cencentration
of various aliphatic alcohols in the mobile phase were investigated. The effect of structural features on the discrimination
between the enantiomers was examined. The isolation of milligram amounts of enantiomers of two derivatives was performed on
an analytical column by multiple repetitive injections under overload conditions. 相似文献
12.
Ghanem A 《Journal of separation science》2007,30(7):1019-1028
Chiralpak IB, a new chiral stationary phase (CSP) containing cellulose tris(3,5-dimethylphenylcarabamate) immobilized onto silica gel, is investigated for the direct enantioselective separation of a set of racemic N-alkylated barbiturates and analogs of thalidomide alkylated in position 3 of the piperidin-2,6-dione ring using different nonstandard solvents such as dichloromethane (DCM), ethyl acetate, THF, methyl tert-butyl ether as an eluent and diluent, respectively, in HPLC. The separation, resolution, and elution order of the investigated compounds were compared on both immobilized and coated cellulose tris(3,5-dimethylphenylcarbamate) CSPs (Chiralpak IB and Chiralcel OD, respectively) using a mixture of n-hexane/2-propanol (90:10 v/v) as mobile phase with different flow-rates and fixed UV detection at 254 nm. The effect of the immobilization of the cellulose tris-(3,5-dimethylphenylcarbamate) CSP on silica (Chiralpak IB) on the chiral recognition ability was noted as the coated phase (Chiralcel OD) possesses a higher resolving power in some cases than the immobilized one (Chiralpak IB). However, a few racemates, which were not or poorly resolved on the immobilized Chiralpak IB or the coated Chiralcel OD when using standard solvents were most efficiently resolved on the immobilized Chiralpak IB upon using nonstandard solvents. Furthermore, the immobilized phase withstands the nonstandard (prohibited) HPLC solvents mentioned previously when used as eluents or as a dissolving agent for the analyte itself. An example of inversion or apparent inversion of elution order on Chiralpak IB is reported. The direct analysis of a spiked plasma sample extracted using DCM on Chiralpak IB is also shown. 相似文献
13.
14.
Several pairs of enantiomers of pharmaceutical intermediates were separated by HPLC directly on cellulose and amylose tris(3,5-dimethylphenylcarbamate) derivatives (Chiralcel OD and Chiralpak AD) using hexane as mobile phase with 2-propanol or ethanol as modifier. The separation and elution order of the enantiomers on the two columns using different alcohol modifiers were compared. Reversal of the elution order of some enantiomeric pairs associated with increased retention of many of these solutes upon changing the mobile phase modifier from 2-propanol to ethanol was observed. The effect of structural variation of two pairs of enantiomers on their k' and separation factor alpha was noted. Chiralcel OD and Chiralpak AD columns provided different retention, separation and elution order of some of the enantiomeric pairs. 相似文献
15.
纤维素-三(3,5-二甲基苯基氨基甲酸酯)涂敷手性固定相的制备、表征及评价 总被引:3,自引:0,他引:3
以纤维素和 3,5 二甲基苯基异氰酸酯为原料合成了纤维素 三 (3,5 二甲基苯基氨基甲酸酯 ) ,并采用两种不同的方法将其涂敷于小粒径 (平均粒径 5 μm ,平均孔径 13nm ,比表面积 110m2 / g)的氨基丙烷化硅胶 (APS)上 ,制得了在纤维素 三 (苯基氨基甲酸酯 )类衍生物涂敷的硅基手性固定相中具有较佳手性识别能力的固定相。通过元素分析、扫描电子显微镜对两种手性固定相进行了表征 ,用高效液相色谱法对两种固定相的手性拆分能力进行了评价和比较。 相似文献
16.
Cirilli R Ferretti R Gallinella B La Torre F La Regina G Silvestri R 《Journal of separation science》2005,28(7):627-634
The enantiomeric separation of a series of imidazole analogues of Fluoxetine and Miconazole endowed with potent antifungal activity was performed using cellulose tris(4-methylbenzoate) (Chiralcel OJ) and cellulose tris(3,5-dimethylphenylcarbamate) (Chiralcel OD) as chiral stationary phases. Binary mixtures of n-hexane and alcohol as well as pure alcohols (ethanol or 2-propanol) were used as eluents. The enantiomer elution order was monitored by chiroptical detectors based on on-line optical rotation and circular dichroism measurements. For some of the compounds studied very high enantioseparation factor values (alpha > 7) on Chiralcel OJ CSP were observed. In order to study the chiroptical characteristics of the two most biologically active compounds, chromatographic resolutions were carried out on a semipreparative scale. Assignment of the absolute configuration was empirically established by comparing the CD spectra of the separated enantiomers with those obtained from the enantiomers of Miconazole. 相似文献
17.
18.
The separation of thalidomide (TD) and its hydroxylated metabolites including their simultaneous enantioseparation was studied using three different polysaccharide-type chiral stationary phases (CSPs) in combination with polar organic mobile phases. Three different techniques, high-performance liquid chromatography in common-size columns, capillary LC and nonaqueous capillary electrochromatography were compared in terms of separation. As this study illustrates, polar organic mobile phases represent a valuable extension for less polar and polar aqueous-organic mobile phases in combination with polysaccharide CSPs. Chiralpak AD consisting of 25% of amylose-tris(3,5-dimethylphenylcarbamate) coated on wide-pore aminopropylsilanized silica gel exhibited higher resolving ability compared to the similar cellulose derivative (Chiralcel OD) as well as to cellulose-tris(4-methylbenzoate) (Chiralcel OJ) CSPs for this particular set of chiral analytes. Baseline separation and simultaneous enantioseparation of all three compounds could be achieved under optimized separation conditions. 相似文献
19.
J.F. Goossens C. Foulon C. Bailly D.C.H. Bigg J.P. Bonte C. Vaccher 《Chromatographia》2004,59(5-6):305-313
Analytical HPLC methods using derivatized cellulose and amylose chiral stationary phases were developed for the separation of the enantiomers of homocamptothecin (hCPT) derivatives which constitute a promising series of potent anticancer agents targeting DNA topoisomerase I. The resolutions were performed using a normal phase methodology with two silica-based celluloses tris-3,5-dimethylphenylcarbamate (Chiralcel OD-H) and tris-methylbenzoate (Chiralcel OJ) or two amyloses tris-3,5-dimethylphenylcarbamate (Chiralpak AD) and tris-(S)-1-phenylethylcarbamate (Chiralpak AS). The mobile phase and the chiral stationary phase were varied to achieve the best resolution. Different types and concentration of aliphatic alcohols in the mobile phase were also tested along with the temperature dependence. An optimal baseline separation (Rs > 1.5) was readily obtained in most cases. The different columns gave complementary results in term of resolution. The limits of detection and quantification were between 0.08–0.40 M and 0.24–1.80 M, respectively and the enantiomeric purity was superior to 99.9%. 相似文献
20.
Analytical HPLC methods using derivatized cellulose chiral stationary phases were developed for the direct enantioseparation of substituted [1-(imidazo-1-yl)-1-phenylmethyl)]-benzothiazolinone and benzoxazolinone derivatives with one chiral center. Those analogues of fadrozole constitute new potent nonsteroidal inhibitors of aromatase (P450 arom). The separations were made using normal phase methodology with a mobile phase consisting of n-hexane-alcohol (ethanol, 1-propanol, or 2-propanol) in various proportions, and a silica-based cellulose tris-3,5-dimethylphenylcarbamate (Chiralcel OD-H), or tris-methylbenzoate (Chiralcel OJ). The effects of concentration of various aliphatic alcohols in the mobile phase were studied. A better separation was achieved on cellulose carbamate phase compared with the cellulose ester phase. The effects of structural features of the solutes along with the temperature of the column on the discrimination between the enantiomers were examined. Baseline separation (Rs > 1.5) was easily obtained in many cases. 相似文献