Chemistry / Kimya
Permanent URI for this collectionhttps://hdl.handle.net/11147/4072
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Article Citation - WoS: 1Citation - Scopus: 1Investigation of Cytotoxic Properties of Some Isoindole-Related Compounds Bearing Silyl and Azide Groups With in Vitro and in Silico Studies(Taylor & Francis, 2023) Tan, Ayşe; Köse, Aytekin; Mete, Derya; Şanlı Mohamed, Gülşah; Kışhalı, Nurhan H.; Kara, YunusThis study aims to evaluate the synthesis of isoindole-1,3-dione analogues and their cytotoxic potential. A549 and HeLa cells exposed to 250-100-50-25 mu M doses of each derivative were incubated for 24, 48, and 72 h. The cytotoxicity of the isoindole-1,3-dione derivatives was analyzed using the cell growth inhibition assay and the cell membrane damage test. (3aR,5R,6R,7aS)-5-Azido-2-benzyl-6-hydroxyhexahydro-1H-isoindole-1,3(2H)-dione (1d), (3aR,5R,6R,7aS)-5-azido-6-((tert-butyldiphenylsilyl)oxy)-2-ethylhexahydro-1H-isoindole-1,3(2H)-dione (2a), and (3aR,5R,6R,7aS)-5-azido-6-((tert-butyldiphenylsilyl)oxy)-2-methylhexahydro-1H-isoindole-1,3(2H)-dione (2b) compounds inhibited the growth of the A549 and HeLa cells caused membrane damage and exhibited a dose-dependent cytotoxic effect on lung and cervical carcinoma cells. The effect of tert-butyldiphenylsilyl (TBDPS) groups on cytotoxicity was observed in compounds 2a and 2b, but not in the other compounds. Considering the effect of groups attached to the nitrogen atom, the best activity was exhibited in 2b molecule to which the methyl group is attached. Additionally, the interactions of compounds (3aR,5R,6R,7aS)-5-azido-6-hydroxy-2-methylhexahydro-1H-isoindole-1,3(2H)-dione (1b), 1d, 2a and 2b with mammalian rapamycin target, human ribosomal S6 kinase 1 and human epidermal growth factor receptor were investigated by molecular docking studies, . According to the docking results, 2a and 2b compounds containing a TBDPS group have stronger binding energies than 1b and 1d compounds against all target receptors.Conference Object Citation - WoS: 3Citation - Scopus: 3Halloysite Nanotube Loaded Polyamide Nanocomposites: Structural, Morphological, Mechanical, Thermal and Processing Behaviors(American Institute of Physics, 2023) Akar, Alinda Öykü; Yıldız, Ümit Hakan; Tayfun, ÜmitIn this study, the polyamide 6 (PA) matrix was reinforced with the purified, fine ground and amino-silane treated halloysite nanotubes (HNT) at different concentrations. The preparation of composites was carried out using a lab-scale twin-screw micro-compounder with loading ratios at 0.5, 1, 3, and 20% by weight, and the test samples were prepared by the injection-molding process. According to mechanical test results, additions of HNT to the PA matrix caused slight improvements in tensile strength and Youngs' modulus parameters. The optimum concentrations for all of the additives used were estimated by comparison of mechanical test data. The addition of aminosilane-modified HNT resulted in a higher impact performance at high loading levels up to 3% concentrations. Further addition of HNT caused a reduction in the mechanical parameters of composites. Thermal studies revealed that the glass transition temperature of PA shifted to higher values after HNT mineral inclusions. Thermo-mechanical results showed that storage moduli of PA exhibited improvement with an increase in HNT content. The distributions of HNT clay into the PA phase were visualized with SEM images. Based on these observations, a high level of dispersion homogeneity was achieved for lower filling ratios. According to melt-flow and force measurements, composites filled with 20% of HNT displayed a remarkable increase in exerted force during melt-blending. © 2023 Author(s).Article Development of Chemometrics Method Based on Infrared Spectroscopy for the Determination of Cement Composition and Process Optimization [article](ACG Publications, 2022) Özdemir, Durmuş; Gümüş, Mehmet Gökhan; Tepeli, DilekIn combination with a multivariate calibration method, FTIR-ATR spectroscopy was presented as a rapid method for the determination of some major oxides (CaO, SiO2, Al2O3, Fe2O3) and minor oxides (MgO, SO4, Na2O, and K2O) in diverse materials (raw material, raw meal, additives, clinker, and types of cement) in cement manufacturing. The FTIR spectroscopy based multivariate models were generated by taking X-ray fluorescence (XRF) as a reference method. Among a number of spectral preprocessing methods, extended multiplicative scatter correction (EMSC) yielded the best PLS models. The standard error of prediction (SEP) for the optimal FTIR based PLS models ranged from 0.10 to 2.07 (w/w%), and the regression coefficient (R2) ranged from 0.95 to 0.99 for PLS predicted vs XRF reference plots. Statistical evaluation of the both methods was carried out by paired t-test at the 95% confidence level and the results showed that the FTIR-ATR combined with PLS model results are consistent with the XRF reference measurements for all the oxides studied. Compared to the XRF method, which can take anywhere from a few minutes to an hour for each measurement, the proposed method is faster, cheaper, and safer. The presented technology also allows rapid monitoring of a cement factory production line.Article Citation - WoS: 11Türkiye’de Kutanöz Leyşmanyazis Etkeni Leishmania Tropica’da Antimon Direnç Mekanizmasının Belirlenme(Ankara Mikrobiyoloji Derneği, 2020) Özbilgin, Ahmet; Zeyrek, Fadile Yıldız; Güray, Melda Zeynep; Çulha, Gülnaz; Akyar, Işın; Harman, Mehmet; Gündüz, CumhurDünya Sağlık Örgütü, yaklaşık bir milyar insanın endemik bölgelerde risk altında olduğunu, son beş yıl içinde bir milyon kutanöz leyşmanyazis (KL) olgusunun ve yılda yaklaşık 300.000 viseral leyşmanyazis (VL) olgusunun olduğunu bildirmektedir. Her yıl yaklaşık 20.000 kişinin VL’ye bağlı öldüğü bilinmektedir. Türkiye’de Leishmania tropica’nın ve Leishmania infantum’un neden olduğu KL’de yılda 2500 civarında olgu bildirilmektedir. Başta Akdeniz ve Ege Bölgesi illerinde olmak üzere diğer birçok ilde son yıllarda ortaya çıkan olgu ve odaklarda önemli oranda artış görülmesi önümüzdeki yıllarda enfeksiyon hızının yükseleceğini göstermektedir. Ülkemizdeki KL’nin ana etkeni L.tropica olup tedavide meglumin antimonat kullanılmaktadır. Bu çalışmada, antimona dirençli ve dirençli olmayan L.tropica izolatlarının gen ve protein ekspresyonları karşılaştırılarak L.tropica’ya özgü antimon direnç genlerinin saptanması amaçlanmıştır. Ülkemizin Ege, Akdeniz ve Güneydoğu bölgelerinden antimonat direnci bulunmayan 3 KL hastasından elde edilmiş L.tropica izolatlarında, laboratuvar ortamında meglumin antimonata karşı 3 dirençli izolat geliştirilmiştir. Bu izolatların mikroarray yöntemi ile gen ekspresyon değişimleri, 2 boyutlu jel elektroforezi ile protein profilleri ve MALDI-TOF/TOF MS ile ilgili proteinleri tanımlanarak birbirleriyle karşılaştırma yapılmıştır. Antimon tedavisine yanıt vermemiş 10 KL hastasından elde edilmiş L.tropica izolatlarına antimon bileşiklerine yönelik direnç testleri uygulanmış ve direnç gelişiminden sorumlu genlerin ekspresyonlarını saptamak amacıyla kantitatif gerçek zamanlı polimeraz zincir reaksiyonu uygulanmıştır. Ayrıca, protein profilleri karşılaştırılarak antimon direnci olan ve olmayan izolatlardaki protein ekspresyon düzeylerindeki farklılıklar belirlenmiş ve farklılık saptanan proteinlerin tanımlanması gerçekleştirilmiştir. Bu çalışmalar sonucunda, L.tropica izolatlarının antimon bileşiklerine karşı direnç geliştirilen izolatlarında, direnç geliştirmesinde enolaz, “Elongation factor-2 (EF-2)”, “Heat shock protein 70 (HSP 70)”, tripanotyon redüktaz, protein kinaz C ve metalo-peptidaz proteinlerinin rol oynadığı saptanmış ve hastalardan alınan doğal dirençli izolatlarda da benzer ekspresyon değişimi gösterilmiştir. Sonuç olarak, ülkemizdeki L.tropica izolatlarının deneysel olarak çok kısa sürede meglumin antimonata (Glucantime®) karşı direnç kazandığı saptanmıştır. Ülkemizde yaşayan ve yurt dışından ülkemize giriş yapan KL hastalarının yetersiz ve eksik tedavi görmesi durumunda, dirençli suşların ve olgu sayısının hızla artabileceği ve dirençli leyşmanyazis odaklarının oluşabileceği öngörülmektedir.Article Citation - WoS: 2Türkiye’de Kutanöz Leyşmanyazis Hastalarından Elde Edilen Leishmania İzolatlarındaki Farklılıklar ve Bunların Fare Modeline Klinik Yansıması(Ankara Microbiology Society, 2020) Özbilgin, Ahmet; Çulha, Gülnaz; Güray, Melda Zeynep; Zeyrek, Fadile Yıldız; Akyar, Işın; Toz, Seray; Gündüz, CumhurAlthough asexual reproduction has been attributed to Leishmania species, genetic exchange has recently been demonstrated, which helped emerging of hybrid isolates. Situated on the crossroads between three continents, Leishmania hybrids may be present in Turkey. In Turkey, visceral leishmaniasis caused by Leishmania infantum is less common, while cutaneous leishmaniasis (CL) caused by Leishmania tropica and L.infantum could reach 2500 reported cases a year. Our aim was to investigate genetic variability of local Leishmania species and presence of hybrid Leishmania strains in Turkey. Twenty CL patients from Sanliurfa and Hatay, where only L.tropica and both L.tropica and L.infantum cause CL, respectively, were registered equally. All isolates were assessed with real-time polymerase chain reaction (Rt-PCR), isoenzyme analysis, gene sequencing, two-dimensional gel electrophoresis (2D-PAGE) and MALDI-TOF/TOF-MS followed by in vivo analyses on mouse model. Identification of differentially expressed proteins was performed. These proteins were confirmed by sequence analysis. All isolates from Sanliurfa were found to be L.tropica which caused cutaneous infection in mice. However, one of 10 isolates from Hatay was found as Leishmania major which caused cutaneous infection. Five isolates were found as L.tropica with Rt-PCR and gene sequencing, one of which had one different protein from the reference L.tropica strain and caused cutaneous infection. Four of the five isolates had five different proteins compared to reference strain and caused both cutaneous and visceral infections. Remaining four isolates showed double melting curves in Rt-PCR, which were concordant with L.tropica and L.infantum. Their sequencing and isoenzyme analyses indicated them as L.infantum. They had six different proteins compared to reference L.infantum strain and caused cutaneous and visceral infections. It is concluded that the isolates with different proteins were hybrid Leishmania species. In the present study, outcomes of the proteomics, genomics, clinical manifestations and tissue tropism on animal models were evaluated together for the first time. In addition to L. tropica and L.infantum, L.major was identified as a causative agent for CL and hybrids of Linfantum/tropica were also shown to be present.