Chemistry / Kimya
Permanent URI for this collectionhttps://hdl.handle.net/11147/4072
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Article Citation - WoS: 17Citation - Scopus: 15Antiproliferative and Apoptotic Effects of Olive Leaf Extract Microcapsules on Mcf-7 and A549 Cancer Cells(American Chemical Society, 2023) Bal, Yıldız; Sürmeli, Yusuf; Şanlı Mohamed, GülşahAlginate microcapsules are a talented means for the delivery of broad curative biomacromolecules. In this study, we immobilized olive leaf extract (OLE) by calcium alginate (CA) and chitosan-coated CA (CCA) and characterized the OLE-loaded CA and CCA. The cytotoxic effect, the cell cycle arrest, and the apoptotic effect of OLE and its microcapsules were investigated against breast adenocarcinoma (MCF-7) and lung carcinoma (A549). As a result, the loading capacity of OLE-CA and OLE-CCA was found to be 80 and 99%, respectively, in optimal conditions. Also, OLE-CA and OLE-CCA were characterized by unique FTIR peaks and morphological display relative to the empty CCA microcapsules. The cytotoxicity analysis showed that the IC50 values of OLE-CA and OLE-CCA were determined to be 312 and 0.94 μg mL-1 against A549, respectively, whereas these were found to be 865.4 and 425.5 μg mL-1 for MCF-7 cells. On the other hand, the OLE microcapsules did not possess in any concentration of cytotoxic influence on the BEAS 2B healthy cell line. Also, the exposure of OLE-CCA to MCF-7 and A549 resulted in the arrest of more MCF-7 and A549 cells at the G0/G1 phase compared to the OLE. A549 and MCF-7 cells were predominantly found in the late apoptosis phase and necrosis phase, respectively. Optical microscopy images confirmed that OLE microcapsules were more effective against MCF-7 and A549 than free OLE. The present work suggested that the OLE microcapsules might be administered as nutrition supplements for cancer therapy. © 2023 The Authors. Published by American Chemical Society.Article Citation - WoS: 2Citation - Scopus: 2Gas Phase Fragmentation Behavior of Proline in Macrocyclic B7 Ions(American Chemical Society, 2023) Taşoğlu, Çağdaş; Arslanoğlu, Alper; Yalçın, TalatThefragmentation characteristics of b (7) ionsproduced from proline-containing heptapeptides have been studiedin detail. The study has utilized the following C-terminally amidatedmodel peptides: PA(6), APA(5), A(2)PA(4), A(3)PA(3), A(4)PA(2), A(5)PA, A(6)P, PYAGFLV, PAGFLVY, PGFLVYA, PFLVYAG,PLVYAGF, PVYAGFL, YPAGFLV, YAPGFLV, YAGPFLV, YAGFPLV, YAGFLPV, YAGFLVP,PYAFLVG, PVLFYAG, A(2)PXA(3), and A(2)XPA(3) (where X = C, D, F, G, L, V, and Y, respectively). The resultshave shown that b (7) ions undergo head-to-tailcyclization and form a macrocyclic structure. Under the collision-induceddissociation (CID) condition, it generates nondirect sequence ionsregardless of the position of the proline and the neighboring aminoacid residues. This study highlights the unusual and unique fragmentationbehavior of proline-containing heptapeptides. Following the head-to-tailcyclization, the ring opens up and places the proline residue in theN-terminal position while forming a regular oxazolone form of b (2) ions for all peptide series. Then, the fragmentationreaction pathway is followed by the elimination of proline with itsC-terminal neighbor residue as an oxazolone (e.g., PXoxa) for all proline-containing peptide series.Article Citation - WoS: 2Citation - Scopus: 6Immobilization of Olive Leaf Extract With Chitosan Nanoparticles as an Adjunct To Enhance Cytotoxicity(American Chemical Society, 2023) Özdamar, Burcu; Sürmeli, Yusuf; Şanlı Mohamed, GülşahWe immobilized the olive leaf extract (OLE) with chitosannanoparticles(CNPs) by optimizing the effect of various immobilization conditions,and OLE-loaded CNPs (OLE-CNPs) were then elaborately characterizedphysicochemically by scanning electron microscopy (SEM), Fourier transforminfrared (FT-IR) spectroscopy, dynamic light scattering (DLS), andatomic force microscopy (AFM). Under optimal conditions, CNPs wereable to accommodate the OLE with a loading capacity of 97.5%. Theresulting OLE-CNPs had a spherical morphology, and their average diameterwas approximately 100 nm. The cytotoxic influence, cell cycle distribution,and apoptosis stage of OLE and OLE-CNPs were analyzed on lung carcinoma(A549) and breast adenocarcinoma (MCF-7) cell lines. In an in vitrocytotoxic assay, IC50 values of OLE-CNPs were determinedto be 540 & mu;g/mL for A549 and 810 & mu;g/mL for MCF-7. Thetreatment of both A549 and MCF-7 with OLE-CNPs caused the highestcell arrest in G0/G1 in a dose-independent manner. OLE-CNPs affectedcell cycle distribution in a manner different from free OLE treatmentin both cancer cells. A549 and MCF-7 cells were predominantly foundin the late apoptosis and necrosis phases, respectively, upon treatmentof 1000 & mu;M OLE-CNPs. Our results suggest that CNPs enhance theutility of OLEs as nutraceuticals in cancer and that OLE-CNPs canbe utilized as an adjunct to cancer therapy.Article Citation - WoS: 41Citation - Scopus: 44Ultralong-Life Quinone-Based Porous Organic Polymer Cathode for High-Performance Aqueous Zinc-Ion Batteries(American Chemical Society, 2023) Büyükçakır, Onur; Yüksel, Recep; Begar, Ferit; Erdoğmuş, Mustafa; Arsakay, Madi; Lee, Sun Hwa; Kim, Sang OukWe synthesized and studied a redox-active quinone-basedporousorganic polymer (rPOP) and found ultralong cycle life: it is a promisingorganic cathode for aqueous zinc-ion batteries (ZIBs). It has highphysicochemical stability and enhanced intrinsic conductivity fromits fused-aromatic conjugated skeleton. rPOP's high porosityallows for efficient Zn2+ infiltration through the poresduring charging-discharging cycles and contributes to the efficientutilization of redox-active quinone units. It delivers a specificcapacity of 120 mAh g(-1) at a current density of0.1 A g(-1) with a flat and long discharge plateau,which is critically important to provide a stable voltage output.It provides ultralong cycle life at a current density of 1.0 A g(-1) for 1000 and at 2.0 A g(-1) for 30 000cycles, with initial capacity retention of 95 and 66%, respectively.The co-insertion (Zn2+ and H+) charge storagemechanism was investigated using various electrochemical measurementsand ex/in situ structural characterization techniques, and is explainedherein. These findings contribute to a better understanding of thestructure-property relationship for rPOP and open a new avenuefor new organic cathode materials for high-performance next-generationaqueous batteries.Article Citation - WoS: 4Citation - Scopus: 5Development of Ab3-Type Novel Phthalocyanine and Porphyrin Photosensitizers Conjugated With Triphenylphosphonium for Higher Photodynamic Efficacy(American Chemical Society, 2022) Albakour, Mohamad; Önal, Emel; Tüncel, Özge; Erdoğan, İpek; Gümüşgöz Çelik, Gizem; Küçük, Tuǧba; Akgül, Bünyamin; Gürek, Ayşe Gül; Özçelik, SerdarThere are a number of lipophilic cations that can be chosen; the triphenylphosphonium (TPP) ion is particularly unique for mitochondrion targeting, mainly due to its simplicity in structure and ease to be linked to the target molecules. In this work, mitochondrion-targeted AB3-type novel phthalocyanine and porphyrin photosensitizers (PSs) were synthesized and their photophysical photochemical properties were defined. Fluorescence quantum yields (φF) are 0.009, 0.14, 0.13, and 0.13, and the singlet-oxygen quantum yields (φΔ) are 0.27, 0.75, 0.57, and 0.58 for LuPcPox(OAc), AB3TPP-Pc, AB3TPP-Por-C4, and AB3TPP-Por-C6, respectively. To evaluate the photodynamic efficacy of the TPP-conjugated PS cell viabilities of A549 and BEAS-2B lung cells were comparatively measured and IC-50 values were determined. AB3TPP-Por-C4, AB3TPP-Por-C6, and AB3TPP-Pc compounds compared to the reference molecules ZnPc and H2TPP were found to be highly cytotoxic (sub-micromolar concentration) under the light. LuPcPox(OAc) is the most effective molecule regarding cell killing (the activity). The cell killing of the TPP-conjugated porphyrin derivatives exhibits a similar response compared to LuPcPox(OAc) when the light absorbing factor of the PS is normalized at 660 nm: TPP-conjugated porphyrins absorb less light (lower extinction coefficient) but produce more radical species (higher singlet-oxygen quantum yield) and therefore effectively kill the cells. The singlet oxygen-producing capacity of AB3TPP-Pc is almost 3 times higher compared to LuPcPox(OAc) and 50% more efficient with respect to ZnPc, suggesting that TPP-conjugated phthalocyanine may serve as a good photosensitizer for photodynamic therapy (PDT). The high singlet oxygen generation capacity of these novel TPP-conjugated porphyrin and phthalocyanine PS suggests that they might be useful for PDT requiring lower photosensitizer concentration and reduced energy deposited through less light exposure.Article Citation - WoS: 17Citation - Scopus: 19Strong Coupling of Carbon Quantum Dots in Liquid Crystals(American Chemical Society, 2022) Sarısözen, Sema; Polat, Nahit; Mert Balcı, Fadime; Güvenç, Çetin Meriç; Kocabaş, Çoşkun; Yağlıoğlu, Halime Gül; Balcı, SinanCarbon quantum dots (CDs) have recently received a tremendous amount of interest owing to their attractive optical properties. However, CDs have broad absorption and emission spectra limiting their application ranges. We herein, for the first time, show synthesis of water-soluble red emissive CDs with a very narrow line width (∼75 meV) spectral absorbance and hence demonstrate strong coupling of CDs and plasmon polaritons in liquid crystalline mesophases. The excited state dynamics of CDs has been studied by ultrafast transient absorption spectroscopy, and CDs display very stable and strong photoluminescence emission with a quantum yield of 35.4% and a lifetime of ∼2 ns. More importantly, we compare J-aggregate dyes with CDs in terms of their absorption line width, photostability, and ability to do strong coupling, and we conclude that highly fluorescent CDs have a bright future in the mixed light-matter states for emerging applications in future quantum technologies.Article Citation - WoS: 15Citation - Scopus: 14Target-Driven Design of a Coumarinyl Chalcone Scaffold Based Novel Ef2 Kinase Inhibitor Suppresses Breast Cancer Growth in Vivo(American Chemical Society, 2021) Önder, Ferah Cömert; Kahraman, Nermin; Atıcı, Esen Bellur; Çağır, Ali; Kandemir, Hakan; Tatar, Gizem; Taşkın Tok, TuğbaEukaryotic elongation factor 2 kinase (eEF-2K) is an unusual alpha kinase involved in protein synthesis through phosphorylation of elongation factor 2 (EF2). eEF-2K is highly overexpressed in breast cancer, and its activity is associated with significantly shortened patient survival and proven to be a potential molecular target in breast cancer. The crystal structure of eEF-2K remains unknown, and there is no potent, safe, and effective inhibitor available for clinical applications. We designed and synthesized several generations of potential inhibitors. The effect of the inhibitors at the binding pocket of eEF-2K was analyzed after developing a 3D target model by using a domain of another a-kinase called myosin heavy-chain kinase A (MHCKA) that closely resembles eEF-2K. In silico studies showed that compounds with a coumarin-chalcone core have high predicted binding affinities for eEF-2K. Using in vitro studies in highly aggressive and invasive (MDA-MB-436, MDA-MB-231, and BT20) and noninvazive (MCF-7) breast cancer cells, we identified a lead compound that was highly effective in inhibiting eEF-2K activity at submicromolar concentrations and at inhibiting cell proliferation by induction of apoptosis with no toxicity in normal breast epithelial cells. In vivo systemic administration of the lead compound encapsulated in single lipid-based liposomal nanoparticles twice a week significantly suppressed growth of MDA-MB-231 tumors in orthotopic breast cancer models in nude mice with no observed toxicity. In conclusion, our study provides a highly potent and in vivo effective novel small-molecule eEF-2K inhibitor that may be used as a molecularly targeted therapy breast cancer or other eEF-2K-dependent tumors.Article Citation - WoS: 6Citation - Scopus: 8Enhanced Spontaneous Emission Rate in a Low-Q Hybrid Photonic-Plasmonic Nanoresonator(American Chemical Society, 2019) Gökbulut, Belkıs; İnanç, Arda; Topçu, Gökhan; Ünlütürk, Seçil Sevim; Özçelik, Serdar; Demir, Mustafa Muammer; İnci, Mehmet NaciIn this paper, CdTe quantum dots (QDs)-doped single electrospun polymer nanofibers are partially coated with gold nanoparticles to form distinct hybrid photonic-plasmonic nanoresonators to investigate the critical role of the cavity-confined hybrid mode on the modification of the spontaneous emission dynamics of the fluorescent emitters in low-Q photonic cavities. A total enhancement factor of 11.2 is measured via a time-resolved experimental technique, which shows that there is an increase of about three times in the spontaneous emission rate for the QDs-doped gold nanoparticle-decorated nanofibers as they are compared with those uncoated ones. The physical mechanism affecting the spontaneous emission rate of the encapsulated QDs in such a hybrid photonic-plasmonic nanoresonator is explained to be due to regeneration of the mode field in the nanofiber cavity upon the interaction of the dipoles with the surface plasmons of distinctive gold nanoparticles that surround the outer surface of the nanofiber.Article Citation - WoS: 13Citation - Scopus: 13Single Chain Cationic Polymer Dot as a Fluorescent Probe for Cell Imaging and Selective Determination of Hepatocellular Carcinoma Cells(American Chemical Society, 2019) Özenler, Sezer; Yücel, Müge; Tüncel, Özge; Kaya, Hakan; Özçelik, Serdar; Yıldız, Ümit HakanThis letter describes formation of single chain cationic polymer dots (Pdots) made of poly[1,4-dimethy1-1-(34(2,4,5-trimethylthiophen-3-yl)oxy)propyl)piperazin-1-ium bromide] conjugated polyelectrolyte (CPE). The single chain Pdot formation relies on a simple process which is a rapid nanophase separation between CPE solution of ethylene glycol and water. Pdots show narrow monodisperse size distribution with a 3.6 nm in diameter exhibiting high brightness and excellent colloidal and optical stability. It has been demonstrated that photoluminescent Pdots provide selective nuclear translocation to hepatocellular carcinoma cells as compared to healthy liver cells. The Pdot labeling effectively discriminates cancer cells in the coculture media. Pdots hold great promise as a luminescent probe to diagnose cancer cells in histology and may guide surgeons during operations to precisely separate out cancerous tissue due to augmented fluorescence brightness.Article Citation - WoS: 21Citation - Scopus: 23Mass Spectrometry of Intact Proteins Reveals +98 U Chemical Artifacts Following Precipitation in Acetone(American Chemical Society, 2017) Güray, Melda Zeynep; Zheng, Shi; Doucette, Alan A.Protein precipitation in acetone is frequently employed ahead of mass spectrometry for sample preconcentration and purification. Unfortunately, acetone is not chemically inert; mass artifacts have previously been observed on glycine-containing peptides when exposed to acetone under acidic conditions. We herein report a distinct chemical modification occurring at the level of intact proteins when incubated in acetone. This artifact manifests as one or more satellite peaks in the MS spectrum of intact protein, spaced 98 u above the mass of the unmodified protein. Other artifacts (+84, +112 u) also appear upon incubation of proteins or peptides in acetone. The reaction is pH-sensitive, being suppressed when proteins are exposed to acetone under acidic conditions. The +98 u artifact is speculated to originate through an intermediate product of aldol condensation of acetone to form diacetone alcohol and mesityl oxide. A +98 u product could originate from nucleophilic attack on mesityl oxide or through condensation with diacetone alcohol. Given the extent of modification possible upon exposure of proteins to acetone, particularly following overnight solvent exposure or incubation at room temperature, an awareness of the variables influencing this novel modification is valued by proteomics researchers who employ acetone precipitation for protein purification.