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  • Küçük Resim
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    The Antibacterial Activity of Essential Oil of Oregano (Origanum Vulgare L.)
    (WFL PUBL, 2010) Özkalp, Birol; Sevgi, Fatih; Özcan, Mustafa; Özcan, Mehmet Musa
    Antibacterial activities of the essential oil of oregano (Origanum vulgare L.) and ampicillin on Escherichia coli RSKK 340, Klebsiella pneumoniae RSKK 06017, Pseudomonas aeruginosa RSKK 06021, Salmonella enteritidis RSKK 96046, Streptococcus pyogones RSKK 413/214, Bacillus cereus RSKK 1122, Staphylococcus aureus RSKK 96090 and methicilline-resistant Staphylococcus aureus (MRSA) were determined. The minimum inhibitory concentration (MIC) for oregano oil against various bacteria varied: while M.luteus (16 mu g/ml) and B.cereus (32 mu g/ml) were susceptible to oregano oil, the others exhibited partly resistance. Except MRSA S. aureus (250 mu g/ml), ampicillin had more effect on K. pneumoniae (128 mu g/ml) and C. albicans (128 mu g/ml) than oregano oil, but very low concentrations of the essential oil were sufficient to prevent microbial growth. Of the bacteria tested, Micrococcus luteus and Bacillus cereus proved to be most susceptible to oregano oil. Oregano oil possessed strong antimicrobial activity compared with the antibiotic. Gram-positive bacteria were more sensitive to the antimicrobial agent in spice than Gram-negative ones.
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    Determination of 1h and 13c nuclear magnetic resonance chemical shift values of glyoxime molecule with experimental and theoretical methods
    (2019) Taşdemir, Halil Uğur; Sevgi, Fatih; Türkkan, Ercan
    In this study, the conformational analysis was performed by the semi-empiricalPM3 method to determine the molecular structure of the glyoxime molecule. Each ofconformer was optimized using the Density Functionals Theory (DFT) with DFT /B3LYP / 6-311G (d, p) method basis set combination. As a result of theoptimization, the most stable structure was determined according to the energy order.The chemical shift values of 1H and 13C, which were Nuclear Magnetic Resonance(NMR) parameters of this stable structure, were calculated in liquid phase and gas phaseusing DFT method and six different basis sets. Furthermore, the effect of intermolecularhydrogen bonding on 1H chemical shift values was investigated by dimer molecularmodeling at the level of B3LYP / 6-31G (d, p) in the DFT method. Also, the 1H and13C chemical shift values of the glyoxime molecule were determined experimentally.Structural analyzes of the glyoxime molecule were made by comparing the calculatedNMR parameters with the experimental NMR parameters.
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    Fe (III), Co(II), Ni(II), Cu(II) and Zn(II) complexes of schiff bases based-on glycine and phenylalanine: Synthesis, magnetic/thermal properties and antimicrobial activity
    (ELSEVIER SCIENCE BV, 2018) Sevgi, Fatih; Bagkesici, Ugur; Kursunlu, Ahmed Nuri; Guler, Ersin
    Zinc (II), copper (II), nickel (II), cobalt (II) and iron (III) complexes of Schiff bases (L-G, L-P) derived from 2-hydroxynaphthaldehyde with glycine and phenylalanine were reported and characterized by H-1 NMR, C-13 NMR, elemental analyses, melting point, FT-IR, magnetic susceptibility and thermal analyses (TGA). TGA data show that iron and cobalt include to the coordinated water and metal:ligand ratio is 1:2 while the complex stoichiometry for Ni (II), Cu (II) and Zn (II) complexes is 1:1. As expected, Ni (II) and Zn (II) complexes are diamagnetic; Cu (II), Co (II) and Fe (III) complexes are paramagnetic character due to a strong ligand of L-G and L-P. The L-G, L-P and their metal complexes were screened for their antimicrobial activities against five Gram-positive (Staphylococcus aureus, Methicillin resistant Staphylococcus aureus (MRSA), Bacillus cereus, Streptococcus mutans and Enterococcus faecalis) and three Gram-negative (Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa) and one fungi (Candida albicans) by using broth microdilution techniques. The activity data show that ligands and their metal complexes exhibited moderate to good activity against Gram-positive bacteria and fungi. (C) 2017 Elsevier B.V. All rights reserved.
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    İndollerin bazı dioksim türevlerinin sentezi, mikrodalga ile furazanlara dönüştürülmesi ve antimikrobiyal etkilerinin incelenmesi
    (Selçuk Üniversitesi Fen Bilimleri Enstitüsü, 2010-09-30) Sevgi, Fatih; Bedük, A. Dinçer
    İndollerle ilgili heterohalkalı yapılar birçok doğal maddenin yapısında bulunmakta ve ilginç biyolojik aktiviteler göstermektedir. Son yıllarda deniz canlılarından çok sayıda bis-indol alkaloitleri izole edilerek antitümör, antimikrobiyal, antiviral etkileri incelenmiş ve biyolojik özellikleri ortaya çıkarılmıştır. Bu çalışmada indollerle ilişkili olarak potansiyel biyoaktif özellikte 30 yeni bileşik sentezlenerek yapıları; 1H-NMR, 13C-NMR, FT-IR, LC-MS ve elementel analiz teknikleriyle aydınlatılmış ve biyolojik özellikleri, antibakteriyel etki çalışmalarıyla ortaya konmuştur. Çalışmanın ilk aşamasında 15 indol türevi dioksim sentezlenmiştir. Dioksimler ilk defa bu tez kapsamında uygulanan oldukça kolay bir metot ile elde edilmiştir. Bu metotta, indoller elektronca zengin 3 numaralı karbon atomundan kloroglioksimler ile etkileşerek, C-C bağlı ?-dioksimler elde edilmektedir. Bu metot ile 1-metil indol, 2-metil indol ve 1,2-dimetil indol bileşiklerinin; dikloroglioksim, anti-klorofenilglioksim, anti-p-klorofenilkloroglioksim, anti-p-tolilkloroglioksim ve anti-klorometilglioksim ile reaksiyonlarından 3 tanesi bis-indol dioksim olmak üzere 15 yeni dioksim sentezlenmiştir. Çalışmanın ikinci aşaması ise bir önceki aşamada sentezlenen dioksimlerin biyoaktif furazanlara (1,2,5-oksadiazol) dönüşümünü içermektedir. 15 yeni indol türevi furazan bileşiği, dioksimlerin mikrodalga ışınlarıyla dehidrasyonu sonucu elde edilmiştir. Kapalı kap mikrodalga sistemi kullanılarak gerçekleştirilen bu metot furazan sentezinde ilk defa uygulanan bir tekniktir. Çalışmanın son kısmında indol türevi dioksim ve furazanların in-vitro antibakteriyel etkileri, disk difüzyon yöntemi ve mikrodilüsyon broth metodu kullanılarak incelenmiştir. Minimum inhibitör konsantrasyon (MİK) değerleri hem spektrofotometrik olarak hem de bir redoks indikatörü olan TTC kullanılarak kolorimetrik metotla bulunmuştur. Sentezlenen bileşiklerden bazıları test mikroorganizmalarına karşı 2-64 ?g/mL aralığında MİK değerleriyle antibakteriyel aktivite göstermiştir.
  • Küçük Resim Yok
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    Synthesis, characterization, and antimicrobial activity of new benzoylthiourea ligands
    (VERSITA, 2009) Kurt, Guelsah; Sevgi, Fatih; Mercimek, Bedrettin
    In this study, new benzoylthiourea derivatives, (E)-N-[(2-benzamidomethyleneamino)ethylcarbamothioyl]benzamide H(3)L', N-(1-(3-benzoylthioureido)propan-2-ylcarbamothioyl)-benzamide H(4)LaEuro(3), (E)-N-[4-(benzamidomethyleneamino)phenylcarbamothioyl]benzamide H(3)LaEuro ', were synthesized. Structures of the compounds were identified by spectroscopic techniques. In addition, all synthesized compounds were evaluated for in vitro antibacterial and antifungal activity. Compound H(3)LaEuro ' exhibited antibacterial activity.
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    Synthesis, spectroscopic characterization and antimicrobial studies of Co(II), Ni(II), Cu(II) and Zn(II) complexes with Schiff bases derived from 5-bromo-salicylaldehyde
    (ELSEVIER SCIENCE BV, 2013) Kursunlu, Ahmed Nuri; Guler, Ersin; Sevgi, Fatih; Ozkalp, Birol
    In this study, the new Schiff base ligands derived from condensation of amine and 5-bromo-salicylaldehyde were characterized. All compounds, the Schiff bases and the metal complexes, were characterized by elemental analyzes, FT-IR, H-1 NMR, C-13 NMR and magnetic susceptibility measurements. The synthesized ligands, along with their metal (II) complexes, were screened for their in vitro antibacterial activity against four Gram-negative (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Salmonella enteritidis) and four Gram-positive (Streptococcus pyogones, Bacillus cereus, Staphylococcus aureus and Methicillin-resistant S. aureus) bacterial strains by using disc diffusion and broth microdilution techniques. The minimum inhibitory concentration (MIC) values were calculated by microplate reader at 620 nm to. optimum result. It was found that all compounds showed mild to moderate antibacterial activity and the Schiff base ligands had a better antibacterial activity than their complexes. (c) 2013 Published by Elsevier B.V.