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    Öğe
    Chemical Characterization, Antibacterial, Antioxidant, and Cytotoxic Activity of Some Essential Oils Against Strains Causing Acne
    (Soc Cosmetic Chemists, 2023) Altun, Mehzat; Yildirim, Nuray; Yapici, Binnur M.
    The potential of essential oils (EOs) as alternatives to antibiotics for the treatment of acne vulgaris is an area of growing interest due to increasing antibacterial resistance. This study aimed to determine antimicrobial efficacy, chemical profile, and the antioxidant and cytotoxic potential of EOs. Antimicrobial activity was assessed using disc diffusion and minimum inhibitory concentration (MIC) assays against Staphylococcus epidermidis ATCC 12228 and Cutibacterium acnes ATCC 6919. The phytochemical content of oils was determined by gas chromatography/mass spectrometry. The 2,2-diphenyl-1-picrylhydrazyl and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide methods were used to detect antioxidant properties and cell viability, respectively. Limonene, p-cymene, linalool, 1.8-cineole, & beta;-santalol, cinnamaldehyde, carvacrol, and eucalyptol were the major components of lemon, tea tree, lavender, laurel, sandalwood, cinnamon, oregano, and eucalyptus EOs, respectively. The MIC/minimum bactericidal concentration values were between 0.03125% and 32% (v/v). Binary combinations of cinnamon/lavender and cinnamon/sandalwood exhibited synergism against both bacteria. The Cinnamomum verum showed the greatest antioxidant activity (IC50: 35.08 & mu;g/ml). The cytotoxic activity of EOs at concentrations between 2% and 0.0625% was evaluated against a mouse fibroblast (NIH 3T3) cell line. In vitro test results revealed that antibacterial effective EOs may be used in development of topical acne therapy after in vivo and clinical trials are carried out.
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    Öğe
    DFT calculation, biological activity, anion sensing studies and crystal structure of (E)-4-chloro-2-[(pyridin-2-ylimino)-methyl]phenol
    (Serbian Chemical Soc, 2018) Yildirim, Nuray; Demir, Neslihan; Alpaslan, Gokhan; Boyacioglu, Bahadir; Yıldız, Mustafa; Unver, Huseyin
    (E)-4-Chloro-2-[(pyridin-2-ylimino)methyl]phenol was synthesized in the reaction of 2-aminopyridine with 5-chlorosalicylaldehyde. The structure of compound was investigated by FTIR, UV-Vis, 1H-NMR, C-13-NMR and X-ray data. In addition, characterization of the compound was realized using theoretical quantum mechanical calculations and experimental spectroscopic methods. The molecular structure of the compound was confirmed using X-ray single-crystal data, NMR, FTIR and UV-Vis, which were in good agreement with the structure predicted by the theoretical calculations using the density functional theory (DFT). Moreover, the antimicrobial activity of the compound was investigated against some bacteria and yeast cultures by the broth microdilution test. UV-Vis spectroscopy studies of the interactions between the Schiff base and calf thymus DNA (CT-DNA) showed that the compound interacts with CT-DNA via electrostatic binding. The colorimetric response of the compound receptors was investigated before and after the addition of an equivalent amount of each anion to evaluate anion recognition properties.
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    Öğe
    Experimental, DFT Calculation, Biological Activity, Anion Sensing Application Studies and Crystal Structure of (E)-4-[(pyridin-3-ylimino)methyl]benzene-1,3-diol
    (Springer/Plenum Publishers, 2018) Unver, Huseyin; Boyacioglu, Bahadir; Zeyrek, Celal Tugrul; Yolal, Devrim; Yıldız, Mustafa; Yildirim, Nuray; Demir, Neslihan
    Crystallographic and spectroscopic studies of (E)-4-[(pyridin-3-ylimino)methyl]benzene-1,3-diol have been performed. Optimized molecular structure, conformational analysis, theoretical vibrational band assignments, nonlinear optical effects, UV-Vis, properties have also been investigated by using density functional theory with the functional B3LYP using the 6-311++G(d,p) basis set. The antimicrobial activities of the compound were investigated for its minimum inhibitory concentration. The colorimetric response of the Schiff base receptors was investigated before and after the addition of an equivalent amount of each anion to evaluate anion recognition properties. A new Schiff base was prepared and characterized. Experimental and theoretical studies on a new Schiff base have been reported. The tautomeric stability of the compound was investigated by experimental and theoretical (DFT). The nonlinear optical (NLO) effects of the compound was predicted using DFT. The antimicrobial activity and anion-sensor properties of the compound were examined. [GRAPHICS] .
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    Öğe
    Synthesis, biological activity, DNA binding and anion sensors, molecular structure and quantum chemical studies of a novel bidentate Schiff base derived from 3,5-bis(triflouromethyl)aniline and salicylaldehyde
    (Elsevier, 2015) Yıldız, Mustafa; Karpuz, Ozge; Zeyrek, Celal Tugrul; Boyacioglu, Bahadir; Dal, Hakan; Demir, Neslihan; Yildirim, Nuray
    Synthesis, biological activity, spectroscopic and crystallographic characterization and density functional theory (DFT) studies of the Schiff base 3,5-bis(triflouromethyl)aniline and salicylaldehyde are reported. It crystallizes as a monoclinic space group P2(1)/c with a = 7.7814(3)angstrom, b = 26.8674(9)angstrom, c = 7A520(2) angstrom, V = 1379.98(8), Z = 4, D-c = 1.6038 g cm(-3), and mu = 0.156 mm(-1). The molecular structure obtained from X-ray single-crystal analysis of the investigated compound in the ground state was compared using Hartree-Fock (HF) and density functional theory (DFT) with the functionals B3LYP and B1B95 using the 6-311++G(d,p) basis set. The antimicrobial activities of the compound were investigated for its minimum inhibitory concentration (MIC). The interaction of the Schiff base with calf thymus DNA was investigated using UV-visible spectra. The colorimetric response of the Schiff base receptors in DMSO was investigated before and after the addition of an equivalent amount of each anion to evaluate the anion recognition properties. (C) 2015 Elsevier B.V. All rights reserved.
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    Öğe
    Synthesis, characterization, biological activity and theoretical studies of a 2-amino-6-methoxybenzothiazole-based fluorescent Schiff base
    (Elsevier, 2019) Alpaslan, Gokhan; Boyacioglu, Bahadir; Demir, Neslihan; Tumer, Yasemin; Yapar, Gonul; Yildirim, Nuray; Yıldız, Mustafa
    A new Schiff base, (E)-3,5-dimethoxy-2-((6-methoxybenzo[d]thiazol-2-ylimino)methyl)- phenol, was prepared from the reaction of 2-amino-6-methoxybenzothiazole and 2-hydroxy-4,6-dimethoxybenzaldehyde and characterized with elemental analysis, FTIR, UV-VIS, NMR and single crystal X-ray diffraction techniques. Frontier molecular orbitals, molecular electrostatic potential, and chemical reactivity descriptors of the synthesized compound were studied using molecular modeling methods. The antibacterial and antifungal activities of the Schiff base were studied for its minimum inhibitory concentration. The compound showed a higher effect on yeast than against bacteria. The interactions of the compound with DNA were studied with the ultraviolet-visible (UV-VIS) spectra and gel electrophoresis method. The experimental results indicated that the 2-amino-6-methoxybenzothiazole-based Schiff base could bind to DNA via an intercalative mode and showed that it cleaved DNA without the need for external agents. Additionally, the Schiff base showed colorimetric sensor properties for fluoride and cyanide anions in dimethyl sulfoxide.