Browsing by Author "Durucasu I."

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    Effects of grilling on luteolin (3′,4′,5,7-tetrahydroxyflavone) content in sweet green bell pepper (Capsicum annuum)
    (Asian Network for Scientific Information, 2007) Durucasu I.; Tokuşoǧlu Ö.
    The content of luteloin in green bell pepper (Capsicum annuum) produced in Turkey were determined by RP-HPLC with DAD detection. The luteloin (3′,4′,5,7-Tetrahydroxyflavone) content of green pepper samples were 46.00±0.76 mg kg-1 f.w. (average). The alterations of luteloin concentrations with heating process (grilling, közleme) and the loss of luteloin amount were also determined. Luteolin contents of grilled peppers were found as 29.96±0.96 mg kg-1 f.w. The method was objective and reproducible for accurate detection of luteloin in green pepper and other pepper varieties. © 2007 Asian Network for Scientific Information.
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    New thiophene-based azo ligands containing azo methine group in the main chain for the determination of copper(II) ions
    (2007) Dinçalp H.; Toker F.; Durucasu I.; Avcibaşi N.; Icli S.
    New kind of azo chromophores containing thiophene moiety and salicyaldimine-based ligand as side chains have been synthesized by a sequential process for optical sensing of Cu2+ metal ions in organic solution. Compounds have been characterized by IR and UV-vis spectrophotometer, 1H NMR, 13C NMR, MS, TGA and CV instruments. Spectral characteristics of the synthesized compounds have been investigated in five organic solvents of different polarity. Polarizibility effects of the solvents on the spectral characteristics and the dipole moments in the excited state are estimated. The fluorescence quantum yields of the synthesized compounds have been calculated to be in the range of 0.0035-0.0095 in solvents of different polarity. The fluorescence emission quenching experiments between the synthesized compounds and electron donor (pyrene, anthracene), electron acceptor (Co2+) compounds give the bimolecular quenching rate constants of 1011 and 1014 M-1 s-1, respectively. The free energies of photo-electron transfer process (ΔGET) between the azo dyes and the quenchers have been found to be about -19 kcal/mol. Cyclic voltammetry studies indicate that synthesized azo ligands undergo two- or three-reversible reduction potentials (versus ferrocene) and give LUMO energy value of -3.07 eV which is lower than that of TiO2 conduction band and has a band gap value of ∼2.5 eV. These results may point that synthesized azo dyes could be used as hole conducting materials in solid DSSC (Dye Sensitized Solar Cell) devices. Thermal decomposition behavior of the azo dyes gives more information about the structure of the studied materials. The photoisomerization behavior of the synthesized compounds has been investigated in ethyl acetate under Xe lamp irradiation in the fluorescence spectrophotometer for 1 h. Photoisomerization rate constants of cis-trans orientation (kc-t) have been found to be about 10-5 s-1. The complexation process of synthesized thienylidene azo dyes gives subtle changes in their absorption spectra. © 2006 Elsevier Ltd. All rights reserved.
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    Fatty acid and conjugated linoleic acid profiles of infant formulas through direct transesterification of acyl lipids
    (Codon Publications, 2007) Tokuşoǧlu Ö.; Durucasu I.; Akalin A.S.; Serin E.; Akşit S.
    Fatty acid (FA) values, including C8:0, C10:0, C12:0, C13:0, C14:0, C16:0, C18:0, C18:l t, C18:l c, C18:2, C18:2 CLA, C20:0, C18:3 and C22:0, in sixteen infant formulas were determined through direct transesterification of acyl lipids with sodium methoxide by capillary gas chromatography. Total FA values ranged from 250.25-256.06 mg/g sample and the conjugated linoleic acid (CLA) (cis-9, trans-11 octadecadienoic acid) values were 1.41-2.02 mg/g sample (p<0.01) in the infant formulas. The total saturated fatty acid, monounsaturated fatty acid and polyunsaturated fatty acid values were also obtained. The C18:3 (linolenic acid (n-3)) values were 0.63-0.88 mg/g sample, whereas the C18:2 (linoleic acid (n-6)) values ranged from 35.64-35.82 mg/g sample. FA standard mix including CLA had linear calibration curves through the origin (R2 = 0.9999). The precision of the analytical method was (using C13:0, methyl tridecanoate, as internal standard) within the 95% confidence limits and the mean recoveries determined for individual fatty acids in infant formulas varied from 99.8 to 100%.
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    Apolar constituents of some biologically active dianthus species from Western Anatolia
    (Springer New York, 2009) Durucasu I.; Mutlu K.; Sik L.; Yasa I.; Arda N.; Kirmizigul S.
    The apolar constituents of four Dianthus (Caryophyllaceae) species were determined by GC-MS. Palmitic, linoleic, and oleic acids were detected as dominant components in all species. D. elegans d'Urv. var. elegans had the highest antioxidant activity. All four species also showed considerable antimicrobial activity against S. epidermidis and C. albicans. © 2009 Springer Science+Business Media, Inc.
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    Optical and photovoltaic properties of salicylaldimine-based azo ligands
    (2010) Dinçalp H.; Yavuz S.; Hakli O.; Zafer C.; Özsoy C.; Durucasu I.; Içli S.
    A series of azo dyes containing salicylaldimine-based ligands as side chains were prepared and characterized. Absorption and emission data in five solvents of different polarities were studied. Photoirradiation studies under an oxygen atmosphere in water showed that the Schiff base side chains enhanced the photo-oxidative stability of the azo chromophore. The electrochemical properties of the dyes were investigated by a cyclic voltammetry. The synthesized salicylaldimine-based azo dyes gave two irreversible oxidation potentials. Complexation behavior of synthesized compounds with titanium (IV) ions was illustrated by the change in their absorption spectra. These ligands are appropriate sensitizers for anchoring to the TiO2 surface chemically in dye-sensitized solar cell (DSSC) productions. Electron injection capacities to TiO2 and photovoltaic performance of the synthesized salicylaldimine-based azo dyes were tested with DSSC. © 2009 Elsevier B.V. All rights reserved.
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    A new analytical method for the determination of phenolic compounds and their antioxidant activities in different wheat grass varieties; [Farkli{dotless} buǧday çimi çeşitlerinin antioksidan aktiviteleri ve fenolik bileşiklerin tayini İçin yeni bir analitik Metod]
    (Cevkor Vakfi, 2014) Akcan Kardas T.; Durucasu I.
    In this work, the phenolic content and antioxidant capacity of wheat grass, Turkish Amber Durum wheat was studied. For this purpose Turkish Amber Durum wheat was germinated at three different times (15, 30 and 40 days). All the wheat samples sprouted in the same organic conditions and then dried with air and without sunlight and placed into an incubator at 50°C overnight. The dried and milled amber wheat grass was extracted with ethyl acetate and compared for their antioxidant capacities against the 2, 2-diphenyl-1- picrylhydrazyl (DPPH.) radical, and at the same time the total phenolic content (TPC) was determined. Phenolic compounds in the extracts were examined by high performance liquid chromatography (HPLC). In this study, by using a new method, nine standards were separately detected within 50 min by using the HPLC system, as previously reported by other authors. The major phenolics, identified in the wheat grass that consisted of ferulic acid, gallic acid, caffeic acid, pcoumaric acid, ellagic acid, benzoic acid, p-hydroxybenzoic acid, syringic acid, quercetin and bha (butylated hydroxyanisole). The highest antioxidant and antiradical activities were detected in Turkish Amber wheat that sprouted in 15 days. This study demonstrates that the importance of wheat grass is due to its high antioxidant activity. Consumption of wheat grass has positive effects on human health such as reduced risk of coronary heart diseases, certain type of cancers and stroke. Due to the high antioxidant effect of wheat grass the aim is to use it as a food preservative. When wheat grass will be used as a natural food preservative, carcinogenic effects of synthetic food preservatives for body would be preserved.