Chiral separation of ketoconazole and itraconazole anti-fungal drugs using experimental and computational approaches

Drugs with multiple chiral centers were observed as very effective for treating various diseases. However, the enantiomeric resolution of multiple chiral center racemates is not much developed compared to racemates having a single asymmetric center. This work aimed to develop a chiral separation met...

Full description

Saved in:

Bibliographic Details
Main Author:	Arsad, Siti Rosilah
Format:	Thesis
Language:	English
Published:	2019
Subjects:	QD Chemistry
Online Access:	http://eprints.utm.my/id/eprint/101945/1/SitiRosilahPhDFS2019.pdf
Tags:	Add Tag No Tags, Be the first to tag this record!

id	my-utm-ep.101945
record_format	uketd_dc
spelling	my-utm-ep.1019452023-07-25T09:43:40Z Chiral separation of ketoconazole and itraconazole anti-fungal drugs using experimental and computational approaches 2019 Arsad, Siti Rosilah QD Chemistry Drugs with multiple chiral centers were observed as very effective for treating various diseases. However, the enantiomeric resolution of multiple chiral center racemates is not much developed compared to racemates having a single asymmetric center. This work aimed to develop a chiral separation method for antifungal drugs using electrokinetic chromatography (EKC) and to elucidate mechanism of enantioseparation using a computer-aided molecular modelling study. Two azole antifungal drugs were selected namely ketoconazole and itraconazole, which consists of two and three chiral centers, respectively. The separation for ketoconazole was achieved using heptakis (2,3,6-tri-O-methyl)-ß-cyclodextrin (TM-ß-CD), a commonly used chiral selector, as it is relatively inexpensive and has a low UV absorbance in addition to an anionic surfactant, sodium dodecyl sulfate. The optimum conditions for chiral separation of ketoconazole was achieved using 10 mM phosphate buffer at pH 2.50 containing 20 mM TM-ß-CD, 5 mM SDS, and 1.0% (v/v) methanol with an applied voltage of 25 kV at 25°C with a 5-s hydrodynamic injection time at 50 mbar. The four ketoconazole stereoisomers were successfully resolved within 17 min (total analysis time was 28 min including capillary conditioning). The migration time precision of this method was examined to give a repeatability and reproducibility with RSDs = 5.80% (n = 3) and RSDs = 8.88% (n = 9), respectively. A computational study, using quantum mechanics calculations with AutoDock and semi-empirical PM3 calculations, were used to predict the enantiodiscrimination of ketoconazole enantiomers. A Density Functional Theory (DFT) single-point calculation at the level of B3LYP/6-311G (d,p) was performed for the PM3-optimized complexes to obtain more accurate binding energy and also electronic structures of the complexes. Molecular docking and DFT were simulated to predict the enantioresolution of itraconazole with two types of cyclodextrins (CDs), TM-ß-CD and (2-hydroxylpropyl)-?-cyclodextrin (HP-?-CD). The difference in energies of the inclusion complexes between the enantiomers and CD is a measure of chiral discrimination, which results in the separation of the enantiomers in the experimental studies. The dual-CD and triple-CD methods were developed for chiral separation of itraconazole using EKC. Highly sulfated ß-cyclodextrin (S-ß-CD), (2-hydroxylpropyl)-ß-cyclodextrin (HP-ß-CD), TM-ß-CD and HP-?-CD were screened as possible chiral selectors for enantioseparation of itraconazole. The enantioseparation of itraconazole was achieved using 10 mM phosphate buffer solution at pH 3.62 containing a mixture of 10 mM of each HP-ß-CD, TM-ß-CD and HP-?-CD and an applied voltage of 25 kV at 25°C. Both computational and experimental investigations complement each other prior to chiral recognition mechanism. Combination of molecular modelling and capillary electrophoresis appears as a new emerging method for chiral analysis of pharmaceutical drugs. 2019 Thesis http://eprints.utm.my/id/eprint/101945/ http://eprints.utm.my/id/eprint/101945/1/SitiRosilahPhDFS2019.pdf application/pdf en public http://dms.library.utm.my:8080/vital/access/manager/Repository/vital:145993 phd doctoral Universiti Teknologi Malaysia Faculty of Science
institution	Universiti Teknologi Malaysia
collection	UTM Institutional Repository
language	English
topic	QD Chemistry
spellingShingle	QD Chemistry Arsad, Siti Rosilah Chiral separation of ketoconazole and itraconazole anti-fungal drugs using experimental and computational approaches
description	Drugs with multiple chiral centers were observed as very effective for treating various diseases. However, the enantiomeric resolution of multiple chiral center racemates is not much developed compared to racemates having a single asymmetric center. This work aimed to develop a chiral separation method for antifungal drugs using electrokinetic chromatography (EKC) and to elucidate mechanism of enantioseparation using a computer-aided molecular modelling study. Two azole antifungal drugs were selected namely ketoconazole and itraconazole, which consists of two and three chiral centers, respectively. The separation for ketoconazole was achieved using heptakis (2,3,6-tri-O-methyl)-ß-cyclodextrin (TM-ß-CD), a commonly used chiral selector, as it is relatively inexpensive and has a low UV absorbance in addition to an anionic surfactant, sodium dodecyl sulfate. The optimum conditions for chiral separation of ketoconazole was achieved using 10 mM phosphate buffer at pH 2.50 containing 20 mM TM-ß-CD, 5 mM SDS, and 1.0% (v/v) methanol with an applied voltage of 25 kV at 25°C with a 5-s hydrodynamic injection time at 50 mbar. The four ketoconazole stereoisomers were successfully resolved within 17 min (total analysis time was 28 min including capillary conditioning). The migration time precision of this method was examined to give a repeatability and reproducibility with RSDs = 5.80% (n = 3) and RSDs = 8.88% (n = 9), respectively. A computational study, using quantum mechanics calculations with AutoDock and semi-empirical PM3 calculations, were used to predict the enantiodiscrimination of ketoconazole enantiomers. A Density Functional Theory (DFT) single-point calculation at the level of B3LYP/6-311G (d,p) was performed for the PM3-optimized complexes to obtain more accurate binding energy and also electronic structures of the complexes. Molecular docking and DFT were simulated to predict the enantioresolution of itraconazole with two types of cyclodextrins (CDs), TM-ß-CD and (2-hydroxylpropyl)-?-cyclodextrin (HP-?-CD). The difference in energies of the inclusion complexes between the enantiomers and CD is a measure of chiral discrimination, which results in the separation of the enantiomers in the experimental studies. The dual-CD and triple-CD methods were developed for chiral separation of itraconazole using EKC. Highly sulfated ß-cyclodextrin (S-ß-CD), (2-hydroxylpropyl)-ß-cyclodextrin (HP-ß-CD), TM-ß-CD and HP-?-CD were screened as possible chiral selectors for enantioseparation of itraconazole. The enantioseparation of itraconazole was achieved using 10 mM phosphate buffer solution at pH 3.62 containing a mixture of 10 mM of each HP-ß-CD, TM-ß-CD and HP-?-CD and an applied voltage of 25 kV at 25°C. Both computational and experimental investigations complement each other prior to chiral recognition mechanism. Combination of molecular modelling and capillary electrophoresis appears as a new emerging method for chiral analysis of pharmaceutical drugs.
format	Thesis
qualification_name	Doctor of Philosophy (PhD.)
qualification_level	Doctorate
author	Arsad, Siti Rosilah
author_facet	Arsad, Siti Rosilah
author_sort	Arsad, Siti Rosilah
title	Chiral separation of ketoconazole and itraconazole anti-fungal drugs using experimental and computational approaches
title_short	Chiral separation of ketoconazole and itraconazole anti-fungal drugs using experimental and computational approaches
title_full	Chiral separation of ketoconazole and itraconazole anti-fungal drugs using experimental and computational approaches
title_fullStr	Chiral separation of ketoconazole and itraconazole anti-fungal drugs using experimental and computational approaches
title_full_unstemmed	Chiral separation of ketoconazole and itraconazole anti-fungal drugs using experimental and computational approaches
title_sort	chiral separation of ketoconazole and itraconazole anti-fungal drugs using experimental and computational approaches
granting_institution	Universiti Teknologi Malaysia
granting_department	Faculty of Science
publishDate	2019
url	http://eprints.utm.my/id/eprint/101945/1/SitiRosilahPhDFS2019.pdf
_version_	1776100809457532928

Chiral separation of ketoconazole and itraconazole anti-fungal drugs using experimental and computational approaches

Similar Items