Chemistry / Kimya
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Article Citation - WoS: 37Citation - Scopus: 41Determination of Olive Oil Adulteration With Vegetable Oils by Near Infrared Spectroscopy Coupled With Multivariate Calibration(SAGE Publications, 2010) Öztürk, Betül; Yalçın, Ayşegül; Özdemir, DurmuşThere has been growing public awareness about the health benefits of olive oil throughout the world in recent years, resulting in a significant increase in its consumption as part of the daily diet This demand has attracted fraudulent attempts to market olive oil which has been adulterated with cheaper oils. This study focuses on the near infrared (NIR) spectroscopic determination of adulteration of olive oil by vegetable oils using multivariate calibration. The binary, ternary and quaternary mixtures of olive, soybean, cotton, corn, canola and sunflower oils were prepared using a random design. The absorbance spectra of these synthetic samples were measured by a near infrared (NIR) spectrometer. A genetic algorithm-based variable selection algorithm, coupled with an inverse least squares multivariate calibration method (GILS) was used to build calibration models for possible adulterants and olive oil in the adulterated mixtures The correlation coefficients of actual versus predicted concentrations resulting from multivariate calibration models for the different oils were between 0 90 and 0.99 The results demonstrated that NIR spectroscopy in conjunction with the GILS method makes it possible to determine the adulteration of olive oils regardless of adulterant vegetable oils over a wide range of concentrations.Article Citation - WoS: 5Citation - Scopus: 5Synthesis and Structures of 1,3,2,4,5-Diazatriborolidines(Elsevier, 2019) Fırıncı, Erkan; Sevinçek, Resul; Bursalı, Banu; Özgener, Hüseyin; Burgaz, Osman; Şen, Ceren; Şahin, YükselThe derivatives of diazatriborolidine are a class of 5-membered heterocyclic compounds containing a ring with two nitrogen atoms and three boron atoms. The 1,3,2,4,5-diazatriborolidine derivatives were synthesized from 1,2-bis(N-lithium-arylamino) diborane(4) and dichloro-dimethylaminoborane with high yield. The structures of these new derivatives were determined using nuclear magnetic resonance (NMR) spectroscopy. The molecular structures of 3a, 3b, 3d, 4b and 4c were determined using single-crystal X-ray diffraction. Their structural features were discussed and compared with similar diazatriborolidines. In addition, the enthalpy of formation of B and N atoms containing five membered heterocycles were calculated theoretically for the first time. Also, an easy and efficient synthesis route has been reported for preparation of 1,3,2,4,5-diazatriborolidine derivatives.Article Citation - WoS: 4Citation - Scopus: 5Mini-Review: "ball-Type Phthalocyanines": Similarities and Differences From Mono Phthalocyanines(Bentham Science Publishers, 2019) Göl, Emre Yusuf; Karabudak, EnginBall-type phthalocyanines are recently synthesized binuclear derivatives of the widely known phthalocyanine molecule. In the ball-type Pc molecule, two cofacially arranged Pc rings have four bridged substituents on the peripheral positions of benzenes. Due to their cofacially arranged phthalocyanine rings and, strong intramolecular and intermolecular interactions, ball-type phthalocyanines have different properties than their parent molecule and these structures have many potential application areas. This review describes three different synthesis methods of ball-type phthalocyanines; synthesis in the solvent, synthesis in solid, and synthesis under microwave irradiation. The synthesis that occurs in the shortest time with the highest yield is the synthesis in the solid phase. General differences between a ball-type phthalocyanine and a monophthalocyanine, such as differences in electronic spectra and effects of cofacial arrangement and central metal atoms, are also discussed. The shape of the Q-bands indicates the differences in electronic spectra. In ball-type Pcs, the Q-bands are broad and have poor resolution. Some potential applications, such as gas sensors, NLO devices, potential usage in photodynamic therapy and artificial photosynthesis of ball-type phthalocyanines are also mentioned. Ball-type Pcs can be used as a sensor for gases such as; CO2, CO, SO2, VOC. A novel water-soluble ball-type Pc may have potential application in PDT. Finally, we consider future prospects of these molecules.Editorial Citation - WoS: 8Citation - Scopus: 9Kras(g12c) Inhibitors on the Horizon(Future Science, 2019) Çağır, Ali; Azmi, Asfar S.RAS proteins (the four isoforms KRAS4A, KRAS4B, NRAS and HRAS encoded by three genes KRAS, NRAS and HRAS) act as molecular switches that when activated drive several key cellular processes such as cell growth, proliferation and survival [1]. In normal cells, RAS activity is under tight control by the precise activation (binding to GTP) and inactivation (GTP hydrolysis to GDP) [1]. As with other critical proteins, it is not at all surprising to note that the gene encoding the RAS protein isoforms is found mutated or altered in a significant proportion of tumors [2]. Mutant RAS loses its ability to hydrolyze GTP and remains in a permanently activated state (bound to GTP) leading to uncontrolled growth.Correction Erratum To: Tannery Wastewater Sediments Produced by Clinoptiolite/Polyacrylamide-aided Flocculation as a Clay Additive in Brick Making(Australian Ceramic Society, 2017) Israil, L. I.; Köseoğlu, Kemal; Cengizler, H.; Polat, Hürriyet[No abstract available]Conference Object Semi-Synthetic Studies on Astragaloside Vii and Immunomodulatory Activities of the Derivatives(Georg Thieme Verlag, 2019) Yakuboğulları, Nilgün; Sağ, Duygu; Çağır, Ali; Bedir, ErdalAdjuvants have been used in vaccine sector since 1920s to increase the immunogenicity of antigens, reduce the dosage and minimize frequency of immunizations [1]. The use of saponins as adjuvant in the prophylactic/therapeutic human and veterinary vaccines, and investigation of their immunomodulatory activities have gained importance in recent years [2],[3]. Astragaloside VII (AST VII), a triterpenoid saponin isolated from Astragalus species, stimulates Th1 mediated immune response, antigen-specific antibody response and splenocyte proliferation.Article Citation - WoS: 21Citation - Scopus: 22Redox-Responsive Release of Active Payloads From Depolymerized Nanoparticles(Royal Society of Chemistry, 2017) Lv, Li-Ping; Jiang, Shuai; İnan, Alper; Landfester, Katharina; Crespy, DanielThe difference in the reactivity of two monomers, aniline (ANI) and 2,5-dimercapto-1,3,4-thiadiazole (DMcT), was employed to design nanoparticles with completely different nanostructures. The monomers were simultaneously polymerized by tandem oxidative polymerization occurring in the miniemulsion droplets. DMcT is also a corrosion inhibitor and its polymer can be depolymerized by reduction, which avoids the unwanted release of the payload DMcT when the capsules are not activated. The redox-responsive release profile of DMcT from the composite particles is controlled by the morphology of the particles and it was investigated for monolithic, multi-hollow, and yolk-shell structures. These PANI/PDMcT composite particles may find potential application in Li-S batteries or in the self-healing systems for corrosion protection.Article Citation - WoS: 3Citation - Scopus: 4Evaluation of Multifunctional Hybrid Analogs for Stilbenes, Chalcones and Flavanones(Bentham Science Publishers, 2017) Çağır, Ali; Odacı, Burcu; Varol, Mehmet; Akçok, İsmail; Okur, Özgür; Koparal, Ayşe T.Aims: In this study, discovery of novel anticancer agents acting by more than one mechanism was aimed. Method: For this purpose, eleven previously synthesized simple-stilbene, chalcone, flavanone derivatives and 31 novel stilbene-fused chalcones and stilbene-fused flavanones were tested for their aromatase inhibition, anti-angiogenic and anti-proliferative properties in cancer (PC3, MCF-7) and healthy (HUVEC) cell lines. MTT cell viability assay was used to evaluate the anti-proliferative activities of the compounds. CYP19/MFC high-throughput screening kit (BD Biosciences, Oxford, UK) was used to search the aromatase inhibition properties and matrigel tube formation assay was applied to determine the anti-angiogenic activities. Results: Results indicate that the simple-chalcone and flavanone derivatives were more cytotoxic than the simple-stilbenes in the both cancer cell lines. In contrast, the simple-stilbene structures were much more effective at aromatase inhibition. The cytotoxicity profiles of stilbene-fused chalcones in cancer cells imply that these molecules mostly mimic the simple chalcone structures. On the other hand, flavanones lose their cytotoxic activities after becoming fused with stilbenes. Additionally, aromatase inhibition assays showed that stilbene-fused chalcones again do mimic the simple-chalcones but not simple-stilbenes and anti-angiogenic profiles of the tested molecules seem to be not related with stilbene fragments. Furthermore, stilbene-fused flavanones may mimic both simple-flavanones and simple-stilbenes depending upon the type and position of the substituent in their respective terminal aromatic rings.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.Article Citation - WoS: 8Citation - Scopus: 10Trypsin-Immobilized Silica: a Novel Adsorbent for V(iv) and V(v) Removal From Water(Water Environment Federation, 2018) Erdem Yayayürük, Aslı; Shahwan, Talal; Şanlı Mohamed, Gülşah; Eroğlu, Ahmet EminIn the present study, trypsin-immobilized silica was employed for the removal of V(IV) and V(V) ions from water. The synthesized sorbent was first characterized and then investigated for the removal of V(IV) and V(V) under various experimental conditions. The adsorption performance of the sorbent was tested as a function of pli, sorbent amount, initial vanadium concentration, contact time, and temperature. The sorption process was then investigated, both from a kinetic perspective and also in terms of isotherm models. The Langmuir adsorption isotherm was the best model to describe the sorption process. Sorption thermodynamics were spontaneous and exothermic. The proposed method was successfully applied to real samples for the removal of V(IV)and V(V) with sufficient accuracy and precision.