Lalehan Akyüz | Aksaray University (original) (raw)

Papers by Lalehan Akyüz

Research paper thumbnail of Production and characterization of chitosan based edible films from Berberis crataegina's fruit extract and seed oil

Innovative Food Science & Emerging Technologies, 2018

Production and characterization of chitosan based edible films from Berberis crataegina's fruit e... more Production and characterization of chitosan based edible films from Berberis crataegina's fruit extract and seed oil

Research paper thumbnail of Synthesis and characterization of a new 2D-imine-linked covalent organic framework

International Journal of Chemistry and Technology

Research paper thumbnail of The effect of polyurethane and carnauba wax on the mechanical and physicochemical properties of acrylonitrile butadiene nitrile rubber coating working gloves

Journal of Elastomers & Plastics

Research paper thumbnail of Characterization of Chitosan-Based Films with Different Aniseed Oil Content

Cumhuriyet Science Journal

Research paper thumbnail of Encapsulation of Flurbiprofen by Chitosan Using a Spray-Drying Method with In Vitro Drug Releasing and Molecular Docking

The Turkish Journal of Pharmaceutical Sciences, 2017

Bu çalışma, herhangi bir çapraz-bağlama ajanı kullanmadan püskürterek kurutma tekniği ile ilaç sa... more Bu çalışma, herhangi bir çapraz-bağlama ajanı kullanmadan püskürterek kurutma tekniği ile ilaç salınımı için, kitosan-flurbiprofen mikro ve nano küreleri hazırlamayı amaçlamaktadır. Ayrıca moleküler modelleme kullanarak kitosan ve flurbiprofen arasındaki bağlanma geometrisini açıklamayı amaçlamaktadır. Gereç ve Yöntemler: Bu çalışmada, püskürterek kurutma tekniği kullanarak flurbiprofenin kitosan ile enkapsülasyonu yapıldı. Kullanılan kitosan, flurbiprofen ve elde edilen kürecikler fourier dönüşümlü kızılötesi spektroskopisi (FT-IR), termogravimetrik analiz (TGA), X-ray difraktometre ve taramalı elektron mikroskopisi (SEM) ile karakterize edildi. Mikro-nano küreciklerdeki ilaç miktarının belirlenmesi için ilaç tutunma verimi çalışıldı. İn vitro salınım çalışmaları pH 7.4 te simüle edilmiş biyolojik sıvı içerisinde gerçekleştirildi. Flurbiprofenin enkapsülasyon prosesi, kitosanın muhtemel bağlanma bölgelerini açıklamak için doking çalışmaları ile birleştirildi. Bulgular: FT-IR sonuçları kitosan ve flurbiprofen arasında H-bağ sisteminin oluştuğunu göstermektedir. Küresel şekilde CS-FP kürecikler SEM ile açıklandı. TGA analizi sonuçları flurbiprofen ve kitosanın termal kararlılıklarının enkapsülasyon sonrası azaldığını göstermektedir. Kürecikler simüle edilmiş biyolojik sıvıda in vitro olarak salınım çalışmaları için kullanılmıştır. Tüm bu analizler enkapsülasyonun %73.28 etki ile başarılı bir şekilde gerçekleştirildiğini göstermektedir. Moleküler modelleme çalışmaları bağlanma enerjisi-3.90 kcal/mol olarak kitosan OH grubu ile ilacın hidroksil (OH) grubu arasında H-bağ sisteminin oluşması ile CS-FP kararlı kompleks yapısının oluştuğunu göstermektedir. Bilgisayar hesaplamaları sonuçları FT-IR dan elde ettiğimiz spektroskopik sonuçları desteklemektedir. Sonuç: Bu çalışma püskürterek kurutma yöntemi ile çapraz-bağ ajanı kullanmadan mikro ve nano küreciklerin hazırlanabileceğini göstermiştir. İlaç salınım çalışması sonuçları, enkapsüle olmuş flurbiprofenin salınımının 48 saat içinde tamamlandığını göstermiştir. Doking analizi sonuçları kitosan ile yeni ilaç taşıyıcı sistemlerin tasarlanması için önerilebilir. Anahtar kelimeler: Biyobozunur, ilaç salınımı, moleküler modelleme, karakterizasyon Objectives: This study aimed to prepare chitosan-flurbiprofen micro-nano spheres as environmentally friendly for drug releasing by spray-drying method without any cross-linking agent. It was also aimed to reveal the favorable binding geometries of chitosan and flurbiprofen using molecular modeling. Materials and Methods: In this study, flurbiprofen was encapsulated with chitosan using spray-drying technique. The used chitosan, flurbiprofen and obtained spheres were characterized via fourier transmission infrared spectrometer (FT-IR), thermogravimetric analysis (TGA), X-ray diffractometer and scanning electron microscopy (SEM). Drug entrapment efficiency was carried out for determination of the drug amount in the micro-nano spheres. In vitro release studies of CS-FP spheres were also examined in the simulated biological fluid at pH 7.4. Encapsulation process of flurbiprofen was combined with the docking studies to investigate the possible binding sites of the chitosan. Results: FT-IR results confirmed that H-bonding system was formed between chitosan and drug. CS-FP spheres with spherical shape were observed by SEM. TGA analysis results showed that thermal stabilities of flurbiprofen and chitosan were decreased after the encapsulation process. The spheres were used for in vitro releasing studies in simulated biological fluids. All these analysis results clearly showed that encapsulation was successfully carried out with 73.28% efficiency. Molecular modeling studies showed that CS-FP stable complexes was formed through a hydrogen bonding system between OH group of the drug molecule and chitosan hydroxyl (OH) group with a binding energy of-3.90 kcal/mol. Our computational results supported to spectroscopic results obtained by FTIR. Conclusion: This study proved that micro-nano spheres can be prepared without using cross-linking agent by spray-drying method. The results of the drug releasing studies showed that release of encapsulated flurbiprofen was completed within 48h. The results of docking analysis can be suggested for the design of new drug carrier systems with chitosan.

Research paper thumbnail of Synthesis, spectroscopic (FT-IR/NMR) characterization, X-ray structure and DFT studies on (E)-2-(1-phenylethylidene) hydrazinecarboximidamide nitrate hemimethanol

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2013

The title molecular salt, (E)-2-(1-phenylethylidene) hydrazinecarboximidamide nitrate hemimethano... more The title molecular salt, (E)-2-(1-phenylethylidene) hydrazinecarboximidamide nitrate hemimethanol C9H13N4(+)·NO3(-)·0.5CH4O, was synthesized and characterized by elemental analysis, FT-IR and NMT spectroscopies, and single-crystal X-ray diffraction technique. Quantum chemical calculations were performed to study the molecular and spectroscopic properties of the title compound, and the results were compared with the experimental findings. The calculated results show that the optimized geometry can well reproduce the crystal structure parameters, and the theoretical vibrational frequencies and GIAO (1)H and (13)CNMR chemical shifts show good agreement with experimental values. The dipole moment, linear polarizability and first hyperpolarizability values were also computed. The linear polarizabilities and first hyper polarizabilities of the studied molecule indicate that the compound is a good candidate of nonlinear optical materials. On the basis of the thermodynamic properties of the title compound at different temperatures have been calculated, revealing the correlations between standard heat capacities (C) standard entropies (S), and standard enthalpy changes (H) and temperatures.

Research paper thumbnail of Production and characterization of chitosan based edible films from Berberis crataegina's fruit extract and seed oil

Innovative Food Science & Emerging Technologies, 2018

Production and characterization of chitosan based edible films from Berberis crataegina's fruit e... more Production and characterization of chitosan based edible films from Berberis crataegina's fruit extract and seed oil

Research paper thumbnail of Synthesis and characterization of a new 2D-imine-linked covalent organic framework

International Journal of Chemistry and Technology

Research paper thumbnail of The effect of polyurethane and carnauba wax on the mechanical and physicochemical properties of acrylonitrile butadiene nitrile rubber coating working gloves

Journal of Elastomers & Plastics

Research paper thumbnail of Characterization of Chitosan-Based Films with Different Aniseed Oil Content

Cumhuriyet Science Journal

Research paper thumbnail of Encapsulation of Flurbiprofen by Chitosan Using a Spray-Drying Method with In Vitro Drug Releasing and Molecular Docking

The Turkish Journal of Pharmaceutical Sciences, 2017

Bu çalışma, herhangi bir çapraz-bağlama ajanı kullanmadan püskürterek kurutma tekniği ile ilaç sa... more Bu çalışma, herhangi bir çapraz-bağlama ajanı kullanmadan püskürterek kurutma tekniği ile ilaç salınımı için, kitosan-flurbiprofen mikro ve nano küreleri hazırlamayı amaçlamaktadır. Ayrıca moleküler modelleme kullanarak kitosan ve flurbiprofen arasındaki bağlanma geometrisini açıklamayı amaçlamaktadır. Gereç ve Yöntemler: Bu çalışmada, püskürterek kurutma tekniği kullanarak flurbiprofenin kitosan ile enkapsülasyonu yapıldı. Kullanılan kitosan, flurbiprofen ve elde edilen kürecikler fourier dönüşümlü kızılötesi spektroskopisi (FT-IR), termogravimetrik analiz (TGA), X-ray difraktometre ve taramalı elektron mikroskopisi (SEM) ile karakterize edildi. Mikro-nano küreciklerdeki ilaç miktarının belirlenmesi için ilaç tutunma verimi çalışıldı. İn vitro salınım çalışmaları pH 7.4 te simüle edilmiş biyolojik sıvı içerisinde gerçekleştirildi. Flurbiprofenin enkapsülasyon prosesi, kitosanın muhtemel bağlanma bölgelerini açıklamak için doking çalışmaları ile birleştirildi. Bulgular: FT-IR sonuçları kitosan ve flurbiprofen arasında H-bağ sisteminin oluştuğunu göstermektedir. Küresel şekilde CS-FP kürecikler SEM ile açıklandı. TGA analizi sonuçları flurbiprofen ve kitosanın termal kararlılıklarının enkapsülasyon sonrası azaldığını göstermektedir. Kürecikler simüle edilmiş biyolojik sıvıda in vitro olarak salınım çalışmaları için kullanılmıştır. Tüm bu analizler enkapsülasyonun %73.28 etki ile başarılı bir şekilde gerçekleştirildiğini göstermektedir. Moleküler modelleme çalışmaları bağlanma enerjisi-3.90 kcal/mol olarak kitosan OH grubu ile ilacın hidroksil (OH) grubu arasında H-bağ sisteminin oluşması ile CS-FP kararlı kompleks yapısının oluştuğunu göstermektedir. Bilgisayar hesaplamaları sonuçları FT-IR dan elde ettiğimiz spektroskopik sonuçları desteklemektedir. Sonuç: Bu çalışma püskürterek kurutma yöntemi ile çapraz-bağ ajanı kullanmadan mikro ve nano küreciklerin hazırlanabileceğini göstermiştir. İlaç salınım çalışması sonuçları, enkapsüle olmuş flurbiprofenin salınımının 48 saat içinde tamamlandığını göstermiştir. Doking analizi sonuçları kitosan ile yeni ilaç taşıyıcı sistemlerin tasarlanması için önerilebilir. Anahtar kelimeler: Biyobozunur, ilaç salınımı, moleküler modelleme, karakterizasyon Objectives: This study aimed to prepare chitosan-flurbiprofen micro-nano spheres as environmentally friendly for drug releasing by spray-drying method without any cross-linking agent. It was also aimed to reveal the favorable binding geometries of chitosan and flurbiprofen using molecular modeling. Materials and Methods: In this study, flurbiprofen was encapsulated with chitosan using spray-drying technique. The used chitosan, flurbiprofen and obtained spheres were characterized via fourier transmission infrared spectrometer (FT-IR), thermogravimetric analysis (TGA), X-ray diffractometer and scanning electron microscopy (SEM). Drug entrapment efficiency was carried out for determination of the drug amount in the micro-nano spheres. In vitro release studies of CS-FP spheres were also examined in the simulated biological fluid at pH 7.4. Encapsulation process of flurbiprofen was combined with the docking studies to investigate the possible binding sites of the chitosan. Results: FT-IR results confirmed that H-bonding system was formed between chitosan and drug. CS-FP spheres with spherical shape were observed by SEM. TGA analysis results showed that thermal stabilities of flurbiprofen and chitosan were decreased after the encapsulation process. The spheres were used for in vitro releasing studies in simulated biological fluids. All these analysis results clearly showed that encapsulation was successfully carried out with 73.28% efficiency. Molecular modeling studies showed that CS-FP stable complexes was formed through a hydrogen bonding system between OH group of the drug molecule and chitosan hydroxyl (OH) group with a binding energy of-3.90 kcal/mol. Our computational results supported to spectroscopic results obtained by FTIR. Conclusion: This study proved that micro-nano spheres can be prepared without using cross-linking agent by spray-drying method. The results of the drug releasing studies showed that release of encapsulated flurbiprofen was completed within 48h. The results of docking analysis can be suggested for the design of new drug carrier systems with chitosan.

Research paper thumbnail of Synthesis, spectroscopic (FT-IR/NMR) characterization, X-ray structure and DFT studies on (E)-2-(1-phenylethylidene) hydrazinecarboximidamide nitrate hemimethanol

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2013

The title molecular salt, (E)-2-(1-phenylethylidene) hydrazinecarboximidamide nitrate hemimethano... more The title molecular salt, (E)-2-(1-phenylethylidene) hydrazinecarboximidamide nitrate hemimethanol C9H13N4(+)·NO3(-)·0.5CH4O, was synthesized and characterized by elemental analysis, FT-IR and NMT spectroscopies, and single-crystal X-ray diffraction technique. Quantum chemical calculations were performed to study the molecular and spectroscopic properties of the title compound, and the results were compared with the experimental findings. The calculated results show that the optimized geometry can well reproduce the crystal structure parameters, and the theoretical vibrational frequencies and GIAO (1)H and (13)CNMR chemical shifts show good agreement with experimental values. The dipole moment, linear polarizability and first hyperpolarizability values were also computed. The linear polarizabilities and first hyper polarizabilities of the studied molecule indicate that the compound is a good candidate of nonlinear optical materials. On the basis of the thermodynamic properties of the title compound at different temperatures have been calculated, revealing the correlations between standard heat capacities (C) standard entropies (S), and standard enthalpy changes (H) and temperatures.