Chiral resolution Dotaz Zobrazit nápovědu
Acta Universitatis upsaliensis. Comprehensive summaries of Uppsala dissertations from the Faculty of Pharmacy. 150, ISSN 0282-7484
31 s. ; 24 cm
o-Phthaldialdehyde was used in combination with a series of six thiosugars for the pre-column chiral derivatization of selected primary amino acids. The diastereomers were resolved on a conventional reversed-phase column and with fluorescence detection. A surprisingly effective resolution of 1-isoindolyl-(1-thioglycosides) derived from 1-thio-beta-L-fucose was observed.
In this short communication we report optimized procedures for the chiral separation of non-charged [6]helicene (1) and cationic derivative 1-butyl-3-(2-methyl[6]helicenyl)-imidazolium bromide (2) using high-performance liquid chromatography (HPLC) and supercritical fluid chromatography (SFC) methods. The possibility of using capillary electrophoresis (CE) was also tested. The satisfactory results were obtained with SFC, where the highly selective resolution of four enantiopure 1 and 2 helicenes was achieved in a single run within 5min. The semi-preparative procedure for the isolation of P and M enantiomers of compound 2, including circular dichroism data, is reported here for the first time. The results could be used in further separations and analytical applications targeting carbohelicenes vs. positively charged helicene derivatives.
V práci sa prezentujú výsledky získané pri použití dvoch chirálnych stacionárnych fáz (CSF), založených na báze glykopeptidového antibiotika – teikoplanín aglykon (CHIROBIOTIK TAG) a metylovaný teikoplanín aglykon – m-TAG. Študovalo sa 21 racemických zmesí 1-metyl-2-piperidínoetylesterov 2-, 3- a 4- alkoxyfenylkarbámovej kyseliny. Skúmali sa interakcie medzi separovanými látkami a CSF, vplyv separácie študovaných enantiomérov na hodnotu rozlišovacieho faktora (Rij) pri dodržaní rovnakých chromatografických podmienok metódou vysokoúčinnej kvapalinovej chromatografie (HPLC). Na základe dosiahnutých výsledkov možno konštatovať, že pre dané typy racemátov je výhodnejšia CSF – CHIROBIOTIK TAG, ktorá neobsahuje sacharidovú časť, čím sa znižuje pravdepodobnosť nepolárnych interakcií, ktoré majú negatívny vplyv na hodnotu Rij.
This paper presents the results obtained with the use of two chiral stationary phases (CSP), based on a glycopeptide antibiotic agent – teicoplanin aglycone (CHIROBIOTIC TAG) and methylated teicoplanin aglycon m-TAG. Twenty-one racemic mixtures of 1-methyl-2-piperidinoethylesters of 2-, 3- a 4- alkoxyphenylcarbamic acid were examined. The investigation included interaction between separated substances and CSP, and the effect of separation of the enantiomers under study on the value of the resolution factor (Rij) under identical chromatographic conditions with the use of the method of high-performance liquid chromatography (HPLC). On the basis of obtained results, it is possible to report that CSP-CHIROBIOTIC TAG is more advantageous for these racemates, because it does not contain a saccharide part, with decrease the possibility of non-polar interactions which exert a negative effect on the Rij value.
Enantiomers of helical N-heteroaromatic dications, helquats, were separated by CE. An acidic 22/35 mM sodium/phosphate background electrolyte, pH 2.4, with addition of randomly sulfated α-, β- and γ- cyclodextrins allowed enantioresolution of a series of helquats, which comprised 5, 6 and 7 fused rings participating in the helical backbone. In general, at least one of the chiral selectors was found to provide baseline separation for 22 out of 24 helquats and partial separation for the remaining two. Individually, the sulfated γ-cyclodextrin turned out to separate 79% of the helquats, followed by the β- and α-congeners with 54 and 42% of the resolved compounds, respectively. Migration order of enantiomers was inspected for selected helquats and a relation of molecular size of the analytes to a cavity of the cyclodextrin selectors is discussed.
A rapid HPLC method for the analytical resolution of cinacalcet enantiomers was developed. Four chiral columns (two amylose and two cellulose type) were evaluated in RP systems. Excellent enantioseparation with a resolution of more than 6 was achieved on Chiralpak AY (amylose 5-chloro-2-methylphenylcarbamate chiral stationary phase) using 10 mM triethylamine (pH 8.0)-acetonitrile (40 + 60, v/v) mobile phase. Validation of the HPLC method, including linearity, LOD, LOQ, precision, accuracy, and selectivity, was performed according to the International Conference on Harmonization guidelines. The method was successfully applied for the determination of (S)-cinacalcet in enantiopure active pharmaceutical ingredient (R)-cinacalcet.
- MeSH
- algoritmy MeSH
- alkoholy MeSH
- indikátory a reagencie MeSH
- koncentrace vodíkových iontů MeSH
- limita detekce MeSH
- naftaleny chemie MeSH
- polysacharidy chemie MeSH
- pufry MeSH
- referenční standardy MeSH
- reprodukovatelnost výsledků MeSH
- rozpouštědla MeSH
- stereoizomerie MeSH
- teplota MeSH
- vysokoúčinná kapalinová chromatografie MeSH
- Publikační typ
- časopisecké články MeSH
