Yazar "Okumu, Veysi" seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • [ X ]
    Öğe
    Design, spectroscopic properties and effects of novel catechol spiroborates derived from Schiff bases in the antioxidant, antibacterial and DNA binding activity
    (Elsevier Science Sa, 2022) Kilic, Ahmet; Soylemez, Rahime; Okumu, Veysi
    Novel catechol spiroborates (L(1-5)B) were prepared from the reaction of the corresponding Schiff base (L(1-5)H) ligands, boric acid, and 3,5-di-ten-butyl catechol under favorable reaction conditions. The synthesized all compounds were characterized by NMR spectra, FT-IR spectra, UV-Vis spectra, LC-MS/MS spectra, fluorescence spectra, elemental analysis as well as the melting point. The optical properties of the Schiff base ligands and catechol spiroborates were investigated using - and fluorescence spectra in the C2H5OH. The antioxidant activities of newly synthesized Schiff base ligands and their catechol spiroborates were investigated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging ability and reducing power ability. Among the synthesized catechol spiroborates, (L2B) exhibited the maximum radical scavenging (91.5 +/- 2.11%) and reducing power activity (0.654 +/- 0.015) at a concentration of 200.0 mu g/mL. Antibacterial activity was determined using 3 Gram positive and 2 Gram negative bacteria by disk diffusion method. Schiff base (L2H) was found to be effective against all test bacteria used. Besides, the DNA binding activity of the catechol spiroborates was determined using Calf Thymus DNA, and the DNA cleavage activity was determined using pBR-322 plasmid DNA by agarose gel electrophoresis method. (C) 2021 Elsevier B.V. All rights reserved.
  • [ X ]
    Öğe
    Synthesis of cis-1,2-diol-type chiral ligands and their dioxaborinane derivatives: Application for the asymmetric transfer hydrogenation of various ketones and biological evaluation
    (Wiley, 2020) Kilic, Ahmet; Balci, Tubba Ersayan; Arslan, Nevin; Aydemir, Murat; Durap, Feyyaz; Okumu, Veysi; Tekin, Recep
    Two cis-1,2-diol-type chiral ligands (T-1 and T-2) and their tri-coordinated chiral dioxaborinane (T(1-2)B(1-2)) and four-coordinated chiral dioxaborinane adducts with 4-tert-butyl pyridine sustained by N -> B dative bonds (T(1-2)B(1-2)-N) were synthesized and characterized by various spectroscopic techniques such as NMR (H-1, C-13, and B-11), FT-IR and UV-Vis spectroscopy, LC-MS/MS, and elemental analysis. It was suggested that both ferrocene and trifluoromethyl groups played key roles in the catalytic and biological studies because they could tune the solubility of the chiral dioxaborinane complexes and adjust the strength of intermolecular interactions. To assess the biological activities of newly synthesized chiral dioxaborinane compounds, DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging, reducing power, antibacterial, DNA binding, and DNA cleavage activities were tested. Then, all chiral dioxaborinane complexes were investigated as catalysts for the asymmetric transfer hydrogenation of various ketones under suitable conditions. The results indicated that the chiral dioxaborinane catalysts performed well with high yields.