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Öğe The effect of vitamin c in the formulation of pectin/thiolated alginate buccal adhesive patches: in vitro and ex vivo evaluation(Elsevier Ltd., 2022) Özkahraman, Bengi; Torkay, Gülşah; Özbaş, Zehra; Bal Öztürk, AyçaThe present study outlines the prospect of a pectin (Pec)/modified alginate (Alg) buccal patch as drug delivery device in the localized treatment of oral cavity diseases. Firstly, Alg was modified with acrylic acid, and thiolated with cystein to enhance its mucoadhesive properties. Then modified Alg was characterized with Fourier transform infrared (FTIR) and proton nuclear magnetic resonance (1HNMR) spectroscopy. As a proof of concept, Pec/modified Alg buccal patches were formed via the conventional solvent casting technique. Then the patches were characterized by FTIR and differential scanning calorimetry/thermal gravimetric analysis (DSC/TGA). Vitamin C (Vit C) was used for in vitro drug release assay, and the release amount was 2.10 mg/g polymer in simulated salivary pH 6.8. Ex vivo mucoadhesion assays of Vit C loaded Pec/modified Alg patch did not have a negative effect on the mucoadhesion feature of the material. The cytotoxicity study indicated that Pec/modified Alg buccal patches did not exhibit apparent cytotoxicity against NIH/3T3 cell lines. Notably, it was found that Vit C in the patch formulation has an accelerating effect on wound healing. According to all results, Vit C loaded Pec/modified Alg buccal patch might be a promising candidate for localized buccal drug release systems.Öğe A new approach for the reuse of scrap carbon fiber in high-added value continuous fiber reinforced composite structures(Elsevier Ltd, 2022) Koçoğlu, Hürol; Kodal, Mehmet; Altan, M. Cengiz; Özçelik, Babür; Özkoç, GüralpThis study proposes an innovative processing approach for high-added value hybrid fiber-reinforced composite structures by reusing scrap carbon fiber (CF). Thermoplastic prepregs were produced via wet-laid method using chopped polyamide 6.6 fibers as matrix and short scrap CFs as the reinforcing phase. These prepregs were then hot stacked with woven glass fabrics, forming a novel hybrid lightweight composite laminate. Silane treatment was used to improve the adhesion of glass fabric to the novel wet-laid scrap CF/PA6.6 prepregs. Tensile, flexural, dynamic-mechanical, and morphological properties of the composites were examined to characterize the effectiveness of the hybridization of short scrap CFs and glass fabric. The results showed that short scrap CF in the laminates increased the tensile strength up to 30 % and flexural strength up to 60 %. Moreover, silane surface modification of the glass fabric yielded a 140 % improvement in the flexural strength of scrap CF/PA6.6 prepreg-glass fabric hybrid laminates.Öğe Hybrid materials based on pyrene-substituted metallo phthalocyanines as sensing layers for ammonia detection: effect of the number of pyrene substituents(Elsevier B.V., 2023) Ivanova, Victoria; Klyamer, Darya; Krasnov, Pavel; Kaya, Esra Nur; Kulu, İrem; Tuncel Kostakoğlu, Sinem; Durmuş, Mahmut; Basova, TamaraIn this work, the effect of the number of pyrene substituents in zinc(II) phthalocyanine molecules on the sensor properties of their hybrid materials with single-walled carbon nanotubes (SWCNT) is studied. For this purpose, hybrid materials of SWCNTs modified with five different trioxyethylenethio substituted zinc(II) phthalocyanines containing 0, 1, 2, and 4 methoxypyrene substituents in the phthalocyanine ring were prepared and characterized by Raman spectroscopy, scanning electron microscopy and inductively coupled plasma atomic emission spectrometry. The chemiresistive sensor response of the prepared hybrids toward low concentrations of ammonia (1–100 ppm) was studied to reveal the effect of the number of pyrene substituents in the phthalocyanine ring on the sensor performance of the hybrid materials. It was demonstrated that the hybrids with zinc(II) phthalocyanine bearing four methoxypyrene substituents exhibited the maximal sensor response to ammonia with the limit of detection of 0.4 ppm. The sensitivity of the hybrid materials to ammonia was shown to be much higher than to CO2, H2, H2S, CH4, ethanol, acetone, and dichloromethane vapors, however, an oxidizing gas such as NO2 was an interfering compound in the determination of ammonia. 1 ppm NO2 show the same absolute value of the response than 10 ppm NH3. The quantum-chemical calculations were performed to explain this effect as well as the dependence of the binding energy of substituted zinc(II) phthalocyanines with carbon nanotubes on the number of pyrene substituents.Öğe In vitro cytotoxic effects, in silico studies, some metabolic enzymes inhibition, and vibrational spectral analysis of novel ?-amino alcohol compounds(Elsevier B.V., 2023) Taş, Ayça; Tüzün, Burak; Khalilov, Ali N.; Taslimi, Parham; Ağbektaş, Tuğba; Çakmak Keklikçioğlu, NeşeIn this study, an efficient single-step method for the preparation of ?-amino alcohols (1–3) in aqueous media was applied. The aim was to investigate the cytotoxic activity of Compounds 1, 2 and 3 in neuroblastoma SH-SY5Y cell line and mouse fibroblast L-929 cell lines. Cytotoxic activities of compounds 1, 2 and 3 in this cell lines were also determined by MTT method. Cells were incubated with different concentrations of Compound 3 showed the highest cytotoxic activity in SHY5Y cells at an IC50 dose of 13.01±0.87 µM at 72 h compared to other compounds. Compound 3 was determined to have lower cytotoxic activity in L-929 cells. The chemical activities of the molecules against the B3LYP, HF, M062X level 3–21 g, 6–31 g, and SDD basis set with the Gaussian package program and biologically against the adenosine A(2A) receptor (PDB ID: 3PWH and 5NM4) proteins for neuroblastoma tumors cell with the Maestro Molecular modeling platform by Schrödinger were compared. Both experimental and theoretical NMR, UV–vis, and IR spectra of the studied molecules were compared. ADME/T analysis was performed to examine the drug properties of the molecules. Finally, these assayed for their activities against metabolic enzymes acetylcholinesterase and ?-glucosidase. The most potent compounds against AChE were order compounds 3, 2 and 1 with Ki values of 35.88±6.61, 43.75±8.28, and 45.34±3.50 µM against AChE, respectively. The results indicated that all the synthesized compounds exhibited excellent inhibitory activities against mentioned enzymes as compared with standard inhibitors. These inhibitors may be candidates for drug design.Öğe Sulfonamide-phosphonate hybrids as new carbonic anhydrase inhibitors: In vitro enzymatic inhibition, molecular modeling, and ADMET prediction(Elsevier B.V., 2023) Zareei, Samira; Mohammadi-Khanaposhtani, Maryam; Adib, Mehdi; Mahdavi, Mohammad; Taslimi, ParhamIn the presented work, we report the synthesis of a new series of sulfonamide-phosphonate hybrids 4a-m. These newly synthesized compounds were assessed for their inhibitory effects toward two human carbonic anhydrase isoforms I and II (hCA I and II). These examined isoforms were as well inhibited by the most of prepared sulfonamide-phosphonates in comparison to standard inhibitor acetazolamide. Obtained data exhibited that compounds 4b-m with Ki values in the range of 8.11–48.08 nM were more potent than standard drug acetazolamide with Ki value of 64.52 Nm against hCA I. Moreover, all the synthesized compounds (Ki values = 7.08–64.24 nM), with the exception of compound 4b, were more potent than acetazolamide (Ki value = 75.36) against hCA II. In particular, sulfonamide-phosphonates 4l and 4j, respectively, with substituents 5?chloro-2-nitro and 2,3-dichloro emerged as the most potent hCA inhibitors. Thereafter, the molecular docking of compounds 4l and 4j at hCA I and II active sites was performed and the obtained results revealed that these compounds interacted whit the important amino acids of the active site. Finally, the predicted parameters of Lipinski's rule of five, ADME, and toxicity analysis showed that compounds 4l and 4j had good drug-likeness and acceptable physicochemical properties. Therefore, the hybridization of the sulfonamide and phosphonate moieties could be promising strategy for achieve to potent lead compounds for inhibition of hCA.Öğe Cytotoxicity effects and biochemical investigation of novel tetrakis-phthalocyanines bearing 2-thiocytosine moieties with molecular docking studies(Elsevier, 2022) Günsel, Armağan; Yıldırım, Aslı; Taslimi, Parham; Erden, Yavuz; Taşkın-Tok, TuğbaIn this study, the novel 3-(4-aminopyrimidin-2-ylthio) phthalonitrile (1) as starting material was synthesized and its molecular structure was verified by the experiment of single crystal X-ray diffraction, and it was first brought to the literature. Then, its non-peripherally tetra-substituted phthalocyanines (2,3) and the methylated derivatives (2a,3a) containing cytosine derivative were synthesized herein for the first time. All the compounds used were characterized with various spectroscopic methods such as UV–Vis, FT-IR, 1H NMR, 13C NMR and MALDI-TOF MS by obtaining highly satisfactory results. The acetylcholinesterase inhibitor compounds recorded as important therapeutic drugs for the therapy of Alzheimer's disease. So, these novel phthalocyanines effectively inhibited acetylcholinesterase enzyme, with Ki values in the range of 31.75 ± 5.72 to 107.15 ± 12.67 µM. For this enzyme, IC50 values were obtained in the range of 3.41 ± 0.78 to 10.08 ± 2.65 µM. For ?-glycosidase enzyme, the most effective Ki values of (3) and (3a) were found as 3.41 ± 0.78 and 5.32 ± 1.34 µM, respectively. We used 50 µL substrates for the acetylcholine esterase and ?-glycosidase enzymes and 20 µL enzymes. For AChE, we used distilled water and buffer 800 µL and 100 µL, respectively. Also, we pipetted 500 µL and 300 µL for ?-glycosidase and examined the activities. Indeed, the most potent phthalocyanines against both enzymes were recorded for the purpose to investigate interaction modes of these compounds in the active site of the target enzyme. After treatment of compounds, viability was reduced by approximately 25% in cancer cell lines. The cytotoxicity potential of these phthalocyanines against human breast, colon, and prostate cancers demonstrated that these compounds had normal cytotoxic effects. © 2022 Elsevier B.V.Öğe A novel practical approach for monitoring the crosslink density of an ethylene propylene diene monomer compound: Complementary scanning acoustic microscopy and FIB-SEM-EDS analyses(SAGE, 2022) Yazıcı, Nazlı; Opar, Ekin; Kodal, Mehmet; Tanören, Bükem; Sezen, Meltem; Özkoç, GüralpTuning of the crosslink density (CLD) in the rubber compounds is very crucial for optimizing the physical and mechanical properties of the ultimate rubber products. Conventionally, CLD can be measured via rheological methods such as moving die rheometer (MDR), via mechanical tests such as temperature scanning stress relaxation analysis (TSSR), or via direct swelling experiments using Flory–Rehner approach. In the current study, two novel techniques, focused ion beam - scanning electron microscopy (FIB-SEM) processing, with simultaneous energy dispersive X-ray spectrometry (EDS) mapping analysis and scanning acoustic microscopy (SAM) were combined and correlated to conventional methods on a model recipe of ethylene propylene diene monomer (EPDM) compound having different sulphur contents. Depending on the applied technique, the increase in the crosslink density with sulphur content was found to be 1.7 fold for the Flory–Rehner approach and 1.2 fold for both TSSR and MDR. It is directly monitored from the FIB-SEM-EDS analysis that the sulphur distribution and agglomeration behavior increased in line with ZnO content, which is an indirect indication of the rise in crosslink density. The impedance maps of the crosslinked samples obtained through SAM analysis revealed that the impedance of the samples increased with the increasing sulphur content, which can be attributed to higher level of crosslink density. A quantified correlation was obtained between SAM images and the crosslink density of the samples. It was shown that SAM is a promising tool for practical and non-destructive analysis for determining the formation of crosslink density of the rubbers. © The Author(s) 2022.Öğe Effects of ov-poss nanoparticles on the vulcanization kinetics of natural rubber compounds(INST ZA KOVINSKE MATERIALE I IN TEHNOLOGIE, 2021) Uçtepe, Ebru; Yazıcı, Nazlı; Kodal, Mehmet; Karaağaç, Bağdagül; Özkoç, GüralpPolyhedral oligomeric silsesquioxanes (POSSs) are new-generation additives, which can provide improved properties of polymer matrices due to physical and/or chemical interactions between the polymer molecules and their reactive sites. In the case of rubber-based polymeric systems, POSSs are also able to accompany a vulcanization reaction. This study aimed to investigate the effect of octavinyl functionalized POSS (OV-POSS) on the sulphur vulcanization of a model natural rubber (NR) based compound. The reaction kinetics was studied using various kinetic approaches based on moving die rheometry and differential scanning calorimetry. Rheometric data was evaluated using a common non-linear cure kinetic model, called the Isayev and Deng Model. The Kissinger, Flynn-Wall-Ozawa and Crane Models were used to evaluate the thermal data for curing reactions. All the models were found to be able to analyze the vulcanization kinetics of OV-POSS containing NR-based rubber compounds as well as the effect of the OV-POSS incorporation.Öğe A review on polyhedral oligomeric silsesquioxanes as a new multipurpose nanohybrid additive for poly(lactic acid) and poly(lactic acid) hybrid composites(WILEY, 2022) Ullah, Muhammad Saeed; Yazıcı, Nazlı; Wis, Abdulmounem Alchekh; Özkoç, Güralp; Kodal, MehmetAbstract The production of petroleum-based polymers in huge amounts is perilous for our ecosystem and oil reserves. The use of biodegradable polymers instead of synthetic polymers for various commodity, engineering, and biomedical applications remains the overriding concern of the researchers in last decades. Although poly(lactic acid) (PLA) is considered to be the most befitting substitute for conventional petroleum-based products because of its superlative mechanical properties, material & processing cost, and non-toxicity, they have some consequential limitations for various applications because of their slow rate of crystallization, low thermal stability, high brittleness, and low toughness. To overwhelm these deficiencies during the last two decades, researchers have developed various techniques to tailor the properties of PLA, that is, blending with other polymers or using additives such as nanofillers. Among all the nanofillers, for example, carbon nanotubes and organoclays, polyhedral oligomeric silsesquioxanes (POSS) was found the most promising nanofiller because of its organic and inorganic nanostructure and fine dispersion into PLA matrix. This article reviews all the investigations relevant to POSS incorporation into PLA or blends of PLA with other polymers to compare the mechanical, morphological, and physical properties of the ameliorated composites and the neat PLA.Öğe 1,3-dipolar cycloaddition reactions of the compound obtaining from cyclopentadiene-PTAD and biological activities of adducts formed selectively(Wiley, 2021) Yavari, Mirali Akbar; Taslimi, Parham; Bayrak, Çetin; Taşkın-Tok, Tuğba; Menzek, AbdullahAfter known adduct (4) was synthesized by cycloaddition reaction of cyclopentadiene with 4-phenyl-1,2,4-triazoline-3,5-dione, seven new isoxazoline derivatives were synthesized from reactions of 4 with corresponding oximes prepared from benzaldehyde derivatives in the existence of the aqueous NaOCl in CH2Cl2 at 0 degrees C-RT via nitrile oxides. Four new pyrazoline derivatives were also synthesized from reactions of 4 with corresponding prepared reagents via nitrile imines. Selectively, each of all isoxazole and pyrazoline derivatives was synthesized by 1,3-dipolar cycloaddition reactions of compound 4 with the corresponding reagents. Based on the results of their biological activity analyses, K-i values for acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and alpha-glucosidase (alpha-Gly) enzymes were obtained in this range 32.15 +/- 5.73-107.44 +/- 19.52 22.57 +/- 4.30-186.07 +/- 23.51, and 69.08 +/- 8.54-528.07 +/- 38.46 nM, respectively. Besides that, these compounds were subjected to molecular docking to describe the interaction against AChE, BChE, and alpha-Gly enzymes in which important interactions were visualized and evaluated with residues of the binding region in each target enzyme.Öğe Biology-oriented drug synthesis and evaluation of secnidazole esters as novel enzyme inhibitors(Wiley, 2021) Ansari, Muhammad A.; Saad, Syed M.; Khan, Khalid M.; Salar, Uzma; Taslimi, Parham; Taskin-Tok, Tuğba; Saleem, Faiza; Jahangir, SajidThe identification of novel compounds that can inhibit physiologically and metabolically important drug targets or enzymes has prime importance in medicinal chemistry. With this aim, a range of secnidazole esters 1–30 were synthesized under the heading of biology-oriented drug synthesis by the 1,1?-carbonyldiimidazole-mediated coupling reaction between secnidazole and varyingly benzoic acid derivatives. All compounds were screened for inhibitory activity against human carbonic anhydrase (hCA) I and II, acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and ?-glucosidase. The results indicate that all the synthesized compounds showed potent inhibitory activities against all targets, as compared to the standard inhibitors, revealed by IC50 values. Ki values of the secnidazole derivatives 1–30 for hCA I, hCA II, AChE, BChE, and ?-glucosidase enzymes were obtained in the ranges of 47.37–190.74, 44.38–198.21, 12.14–68.37, 8.04–61.53, and 7.78–45.91?nM, respectively. To assess the enzyme–ligand interactions, the optimized most active compounds 2, 3, 8, 9, 14, 17, and 23 were subjected to molecular docking studies with modeled AChE, BChE, hCA I, hCA II, and ?-glucosidase enzymes, where several important and key interactions were monitored with amino acid residues of each target enzyme.
