Anti-Acetylcholinesterase and Antioxidant Assets of the Major Components (Salicin, Amentoflavone, and Chlorogenic Acid) and the Extracts of Viburnum opulus and Viburnum lantana and Their Total Phenol and Flavonoid Contents

Ilkay Erdogan-Orhan,Mehmet Levent Altun,Betül Sever-Yilmaz,Gülçin Saltan 한국식품영양과학회 2011 Journal of medicinal food Vol.14 No.4

Some Viburnum species are used for preparation of the traditional drink called gilaburu in Anatolia. In the current study, our goal was to evaluate acetylcholinesterase (AChE) inhibitory and antioxidant activities of the ethyl acetate, methanol, and water extracts prepared from the branches, leaves, and fruits of Viburnum opulus and Viburnum lantana along with salicin, amentoflavone, and chlorogenic acid, three major compounds abundantly found in these species. AChE enzyme inhibition was tested in vitro using an enzyme-linked immunosorbent assay microplate reader at 50, 100, and 200 μL/mL concentrations. Antioxidant activity was examined by ferrous ion chelating capacity, ferric reducing antioxidant power, and β-carotene bleaching assay at 500, 1,000, and 2,000 μg/mL. Total phenol and flavonoid contents of the extracts were also established by Folin-Ciocalteau and AlCl_3 reagents, respectively. Our data revealed that the leaf methanol extract of V. opulus displayed a significantly high inhibitory effect against AChE (57.63 ± 1.23%, 87.41 ± 0.99%, and 93.19 ± 0.87% at 50, 100, and 200 μg/mL, respectively). The extracts of V. lantana exerted higher antioxidant activity.

Terpenoids from Two Sponge Species of the Aegean Sea

Ilkay Erdogan,Junichi Tanaka,Tatsuo Higa,Bilge Sener 한국생약학회 1999 Natural Product Sciences Vol.5 No.4

The ethanolic extracts of two shallow water sponge species collected from the Aegean Sea afforded thirteen terpenoids in total, two of which were determined to be new. The structure elucidation of the terpenoids was carried out by spectroscopic techniques and comparison with related authentic compounds. The terpenoids have also been assayed for antibacterial activity. This is the first report about the metabolites isolated from the marine sponges of the Aegean Sea in Turkey.

Radical Quenching Activity, Ferric-Reducing Antioxidant Power, and Ferrous Ion-Chelating Capacity of 16 Ballota Species and Their Total Phenol and Flavonoid Contents

Ilkay Erdogan-Orhan,Betül Sever-Yılmaz,M. Levent Altun,Gülçin Saltan 한국식품영양과학회 2010 Journal of medicinal food Vol.13 No.6

The ethyl acetate, methanol, and water extracts of 16 Ballota species (Family Lamiaceae)—Ballota acetabulosa, Ballota antalyanse, Ballota cristata, Ballota glandulosissima, Ballota inaequidens, Ballota larendana, Ballota latibracteolata, Ballota macrodonta, Ballota nigra ssp. anatolica, B. nigra ssp. foetida, B. nigra ssp. nigra, B. nigra ssp. uncinata, Ballota pseudodictamnus ssp. lycia, Ballota rotundifolia, Ballota saxatilis ssp. brachyodonta, and B. saxatilis subsp. saxatilis—were screened for their 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical quenching, ferric-reducing antioxidant power, and ferrous ion-chelating capacity at 1mg/mL. Hispanolone, a major diterpene found in the Ballota genus, was also tested in the same manner. Total phenol and flavonoid contents of the extracts were determined by Folin-Ciocalteau and AlCl3 reagents, respectively. The extracts showed insignificant quenching activity against DPPH radical, but they had moderate antioxidant activity (0.597±0.03 to 1.342±0.01) in the ferric-reducing test compared to chlorogenic acid (the reference compound) (3.618±0.01). All of the extracts (ranging from 65.1±0.64% to 96.3±0.09%) and hispanolone (97.31±0.30%) exerted a remarkable ferrous ion-chelating effect. The highest total phenol (gallic acid equivalent) and flavonoid (quercetin equivalent) contents were found in the ethyl acetate extract of B. glandulosissima (393.7±3.03 and 140.6±1.97mg/g of extract, respectively). Therefore, Ballota species could be a good source of natural preservatives in foodstuffs.

Characterizations and properties of oligoazomethines (including CH3 and NO2 groups) char composites

Ilkay Ozaytekin 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.4

In this research, the oligomers were synthesized by the polycondensation of diamins (1,4-diamino-2-nitrobenzene and 2,5-diaminotoluene sulfate) with dialdehydes (terephtaldehyde 4,40-diformylbiphenyl,bis(4-formylphenyl) ether and p-phenylene diacrolein). In this study, the oligoazomethines (OAMs)were studied using IR and UV–visible spectra and X-ray diffraction. The initial degradation temperatures (IDT) determined from TGA of OAMs were in the range of 225–2708C indicating their good thermal stability. The conductivity measurements of OAMs were carried out with an electrometer using fourpoint probe technique. The highest conductivity increase among all the oligoazomethine/char composites was observed for the OAMs composites formed with 30% char ratio.

Immobilization of Candida rugosa Lipase on Magnetic Biosilica Particles: Hydrolysis and Transesterification Studies

Ilkay Acıkgoz-Erkaya,Gulay Bayramoglu,Aydin Akbulut,Mehmet Yakup Arica 한국생물공학회 2021 Biotechnology and Bioprocess Engineering Vol.26 No.5

Biodiesel is a renewable fuel used mainly in diesel engines. At the present time, biodiesel is largely produced by acid or alkali transesterification reactions. A hot spring water algae isolate "Kamptonema formosum" was cultivated at three different temperatures, and the algae oil was extracted using chloroform and methanol (v/v, 1/1 ratio) as the solvent. The maximum amount of algal biomass (1.86 g/L) was obtained at 25°C, and the extracted oil was found to be 48.7% of the total dry biomass. Diatomic earth particles (Biosilica) were magnetized via thermal coprecipitation reaction, and then it was grafted with polydopamine (MBioSi@PDA). The lipase was covalently immobilized on the surface of the MBioSi@PDA via Schiff’s base reaction. The immobilization conditions were optimized and 3.0 mg/mL as the initial lipase concentration in the immobilization medium was found to be the most favorable. At this lipase concentration, the amount of the immobilized lipase on the MBioSi@PDA particles and immobilization yield were found to be 81.9 mg/g and 67.9%, respectively. The MBioSi@PDA@lipase particles were used for conversion of K. formosum oil into biodiesel, and the conversion yield was found as 91.2% under optimum conditions. The fatty acid methyl ester (FAME) compositions of the alga oil were identified using a gas chromatography-mass spectrometry (GC-MS). K. formosum oil mainly composed of the required fatty acids (i.e., 16 and 18 carbon long-saturated and unsaturated fatty acids) for biodiesel synthesis, and these were advantageous for synthesis of biodiesel from the algal oil.

Acute Lymphoblastic Leukemia Presented as Multiple Breast Masses

Ilkay Koray Bayrak,Turkay Yalin,Zafer Ozmen,Tolga Aksoz,Roula Doughanji 대한영상의학회 2009 Korean Journal of Radiology Vol.10 No.5

Breast metastases in cases leukemia are very rare and occur primarily in patients with acute myeloid leukemia. We report the involvement of breast metastases in a 30-year-old woman with acute T cell lymphoblastic leukemia. The patient’s mammograms revealed an extremely dense pattern with ill-defined, denser mass-like lesions in both breasts. A bilateral breast ultrasonographic evaluation revealed lobular-shaped and partly ill-defined hypoechoic masses with a multi-septated nodular (mottled) appearance.

A Comparison of Low-Dose and Normal-Dose Gadobutrol in MR Renography and Renal Angiography

Ilkay Koray Bayrak,Zafer Ozmen,Mehmet Selim Nural,Murat Danaci,Baris Diren 대한영상의학회 2008 Korean Journal of Radiology Vol.9 No.3

Objective: It has been advocated that a reduced injection volume with highly concentrated (1 M) contrast material can produce a sharper bolus peak and an increased intravascular first-pass gadolinium concentration when compared with the use of a lower concentration (0.5 M). A higher concentration would also cause a reduction in dose. The purpose of our study was to test the use of a low dose (0.05 mmol/kg) of gadobutrol in magnetic resonance renography and angiography and compare the findings with a dose of 0.1 mmol/kg. Materials and Methods: One-hundred-thirty-four patients referred for magnetic resonance angiography for suspected renovascular disease participated in the study. Contrast enhanced MR renography and angiography were performed after administration of a bolus of 0.1 mmol/kg or 0.05 mmol/kg gadobutrol in randomized patients. The relative signal intensity-time curves of the aorta, peripheral cortex and parenchyma, were obtained. Two radiologists evaluated the angiographic images and evaluated the quality of angiography. Results: The signal intensity with a low dose of gadobutrol was significantly lower in early phases, in the peripheral cortex (for 36, 54, 72 and 90 seconds), the parenchyma (for 36, 54, 72 seconds) and the aorta (for 18, 36, 54, 72 seconds). The decreases in the early phase obtained with a low dose of gadobutrol caused blunter time intensity curves. The difference in the quality scores of the readers for the angiographic images for the use of the two different doses was not statistically significant (p > 0.05). Conclusion: A lower dose of gadobutrol can be used for MR renal angiography, but for MR renography the normal dose should be used. Objective: It has been advocated that a reduced injection volume with highly concentrated (1 M) contrast material can produce a sharper bolus peak and an increased intravascular first-pass gadolinium concentration when compared with the use of a lower concentration (0.5 M). A higher concentration would also cause a reduction in dose. The purpose of our study was to test the use of a low dose (0.05 mmol/kg) of gadobutrol in magnetic resonance renography and angiography and compare the findings with a dose of 0.1 mmol/kg. Materials and Methods: One-hundred-thirty-four patients referred for magnetic resonance angiography for suspected renovascular disease participated in the study. Contrast enhanced MR renography and angiography were performed after administration of a bolus of 0.1 mmol/kg or 0.05 mmol/kg gadobutrol in randomized patients. The relative signal intensity-time curves of the aorta, peripheral cortex and parenchyma, were obtained. Two radiologists evaluated the angiographic images and evaluated the quality of angiography. Results: The signal intensity with a low dose of gadobutrol was significantly lower in early phases, in the peripheral cortex (for 36, 54, 72 and 90 seconds), the parenchyma (for 36, 54, 72 seconds) and the aorta (for 18, 36, 54, 72 seconds). The decreases in the early phase obtained with a low dose of gadobutrol caused blunter time intensity curves. The difference in the quality scores of the readers for the angiographic images for the use of the two different doses was not statistically significant (p > 0.05). Conclusion: A lower dose of gadobutrol can be used for MR renal angiography, but for MR renography the normal dose should be used.

The influence of the initial stresses on Lamb wave dispersion in pre-stressed PZT/Metal/PZT sandwich plates

Ilkay Kurt,Surkay D. Akbarov,Semih Sezer 국제구조공학회 2016 Structural Engineering and Mechanics, An Int'l Jou Vol.58 No.2

Within the scope of the plane-strain state, by utilizing the three-dimensional linearized theory of elastic waves in initially stressed piezoelectric and elastic materials, Lamb wave propagation and the influence of the initial stresses on this propagation in a sandwich plate with pre-stressed piezoelectric face and pre-stressed metal elastic core layers are investigated. Dispersion equations are derived for the extensional and flexural Lamb waves and, as a result of numerical solution to these equations, the corresponding dispersion curves for the first (fundamental) and second modes are constructed. Concrete numerical results are obtained for the cases where the face layers’ materials are PZT-2 or PZT-6B, but the material of the middle layer is Steel (St) or Aluminum (Al). Sandwich plates PZT-2/St/PZT-2, PZT- 2/Al/PZT-2, PZT-6B/St/PZT-6B and PZT-6B/Al/PZT-6B are examined and the influence of the problem parameters such as piezoelectric and dielectric constants, layer thickness ratios and third order elastic constants of the St and Al on the effects of the initial stresses on the wave propagation velocity is studied.

Effect of fiber orientation on interfacial fracture toughness for adhesively bonded composite plates

Ilkay Ertugrul Bican,Mete Onur Kaman,Serkan Erdem 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.2

In this study, interfacial fracture toughness was investigated experimentally and numerically in laminated composite plates with different fiber reinforcement angles bonded with adhesive. The composite plates are four-layered and the layer sequence is [0º/θ] s . DCB test was applied to composite plates reinforced with epoxy resin matrix and unidirectional carbon fiber. The experimental sample model for the DCB test was made using the ANSYS finite element package program. In the numerical study, four layered composites were prepared in three dimensions. Under critical displacement value; mode I fracture toughness at the crack tip was calculated using VCC (virtual crack closure) technique. Numerical values consistent with experimental results have presented in graphical forms. At 60 o and 75 o the greatest fracture toughness was obtained. In addition, numerical results have shown that fiber orientation prevents the uniform distribution of stress on the interface crack tip and causes stress accumulation, especially at the edge of the plate.

Production and characterization of a new targeted pH-responsive sporopollenin system for controlled drug release

Kubra Yilmaz,Ilkay Hilal Gubbuk,Esra Maltas Cagil 한국고분자학회 2024 Macromolecular Research Vol.32 No.1

A new pH stimuli drug carrier platform was fabricated based on amine modified sporopollenin for targeted and controlled drug delivery. For this purpose, human serum albumin (HSA) was immobilized on 3-aminopropyltrimethoxysilane functionalized sporopollenin (Sp-APTS). Then, irinotecan (IR) was loaded to the albumin modified sporopollenin at various pH levels (2.2, 4.0, 6.0, 7.4, and 9.0). The release studies of irinotecan from drug loaded sporopollenin systems were carried out by using buffers at various pH levels such as 2.2, 4.0, 6,0, 7.4, and 9.0. The loading and release amount of IR were determined by using fluorescence spectroscopy. the results showed that the maximum loading pH was pH 4.0 with 23.44 μg. we evaluate the results in terms of the controlled release, the systems are more controllable towards basic region after pH 4.0 depends on time and pH level. Characterization of the systems was run by using thermal gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) analysis. One of the biodegradable biopolymers, polysaccharide based controlled drug delivery system makes the pharmaceutical formulation more bioavailable in cancer therapy.