A New Fluorescent "Turn-Off" Coumarin-Based Chemosensor: Synthesis, Structure and Cu-Selective Fluorescent Sensing in Water Samples

KARAOGLU, Kaan/0000-0003-3265-8328; KARAOGLU, Kaan/0000-0003-3265-8328WOS: 000403468400012PubMed: 28283898We report the synthesis and characterization two coumarin-based fluorescence probes, N'-{[7-(diethylamino)-2-oxo-2H-chromen-3-yl]carbonyl}pyridine-3-carbohydrazide (3) and N'-benzoyl-7-(diethylamino)-2-oxo-2H-chromene-3-carbohydrazide (4), proposed as a novel fluorescent chemosensor. the two probes designed showed an instant turn-off fluorescence response to Cu2+ over other metal ions in ethanol-water mixture based on intramolecular charge transfer (ICT). It was found that pyridine-analogue coumarin is highly selective and sensitive sensor for Cu2+. the 3 sensor coordinates Cu2+ in 1:1 stoichiometry with a binding constant, K-a = 5.22 M-1 and the detection limit was calculated 1.97 x 10(-9) M.Recep Tayyip Erdogan University Scientific Research Project Unit (RTEUBAP) [FBA-2016-662]This work was supported by Recep Tayyip Erdogan University Scientific Research Project Unit (RTEUBAP) under the project number of FBA-2016-662. the authors thank all the colleagues in the project unit for their supportive attitude

Mononuclear Cu(II) complex of an oxime ligand derived from N-Heterocyclic hydrazide: Synthesis, spectroscopy, electrochemistry, DFT calculations and catecholase activity

emirik, mustafa/0000-0001-9489-9093; KARAOGLU, Kaan/0000-0003-3265-8328WOS: 000471652700049A new oxime derivative N-heterocyclic hydrazide ligand, N'-[(1E,2E)-2-(hydroxyimino)-1-methylpropylidene]-2-[(4-methyl-5-phenyl-4H-1,2,4-triazol-3-1)thio] acetohydrazide (1) and its mono-nuclear copper(II) complex (1a) have been synthesized and characterized by using IR, UV-Vis, NMR and MALDI-TOF mass spectrometry. DFT-based molecular orbital energy calculations and electrochemical behaviors of the compounds have been also studied to explain redox potential of the compounds. the catecholase-mimetic activity of the Cu(II) complex (1a) has been investigated by monitoring the formation of 3,5-di-tert-butyl-benzoquinone from 3,5-di-tert-butylcatechol. Irreversible electrochemical ring-closing of the ligand by oxidation is proposed. Electrochemical ring-closing reaction is shielded by the coordination of Cu(II) to the oxime moiety of the ligand and the title complex undergoes quasi-reversible oxidation and irreversible reduction. Under aerobic conditions, the title copper(II) complex behaves as an effective catalyst towards oxidation of 3,5-di-tert-butylcatechol to its corresponding quinone derivative in MeOH. the turnover number was found as 100.1 h(-1). (C) 2019 Elsevier B.V. All rights reserved.Research Fund of Recep Tayyip Erdogan UniversityRecep Tayyip Erdogan University [FDK-2018-965]This work was supported by the Research Fund of Recep Tayyip Erdogan University, Project No: FDK-2018-965 (Rize/Turkey). the numerical calculations reported in this paper were performed at TUBITAK ULAKBIM, High Performance and Grid Computing Center (TRUBA Resources)

Ferrocenyl-substituted dinuclear Cu(II) complex: Synthesis, spectroscopy, electrochemistry, DFT calculations and catecholase activity

emirik, mustafa/0000-0001-9489-9093; yilmaz, ismail/0000-0002-5046-7456; KARAOGLU, Kaan/0000-0003-3265-8328; KARAOGLU, Kaan/0000-0003-3265-8328WOS: 000367482700038A new ferrocenyl-substituted heterocyclic hydrazide ligand and its Cu(II) complex were prepared. the DFT calculations were performed to determine the electronic and molecular structures of the title compounds. the electronic spectra were calculated by using time-dependent OFF method, and the transitions were correlated with the molecular orbitals of the compounds. the bands assignments of IR spectra were achieved in the light of the theoretical vibrational spectral data and total energy distribution values calculated at DFT/B3LYP/6-311-1-+G(d,p) level. the redox behaviors of the ferrocene derivatives were investigated by cyclic voltammetry. the compounds show reversible redox couple assignable to Fc+/Fc couple. the copper(II) complex behaves as an effective catalyst towards oxidation of 3,5-di-tert-butylcatechol to its corresponding quinone derivative in DMF saturated with O-2. the reaction follows Michaelis Menten enzymatic reaction kinetics with turnover numbers 2.32 x 10(3). (C) 2015 Elsevier B.V. All rights reserved.Research Fund of Recep Tayyip Erdogan University (Rize/Turkey)Recep Tayyip Erdogan University [2011.102.02.1]This work was supported by the Research Fund of Recep Tayyip Erdogan University, Project No: 2011.102.02.1 (Rize/Turkey). the numerical calculations reported in this paper were performed at TUBITAK ULAKBIM, High Performance and Grid Computing Center (TRUBA Resources)

Composition of Volatile Components and Biological Activities of Aethionema diastrophis

EYUPOGLU, Ozan Emre/0000-0002-4449-0537WOS: 000400195700044[No abstract available]KTU Research FundKaradeniz Technical University [5581]This study was supported by the KTU Research Fund (Project No. 5581)

BIOLOGICAL ACTIVITY AND CHARACTERIZATION OF VOLATILE COMPOUNDS OF TEUCRIUM ORIENTALE VAR. GLABRESCENS BY SPME AND GC-FID/MS

EYUPOGLU, Ozan Emre/0000-0002-4449-0537; Alpay Karaoglu, Sengul/0000-0003-1047-8350WOS: 000397284000031This study describes the constituents of phenolic acids, volatile components, antioxidant and antimicrobial activities of Teucrium orientale var. glabrescens. Antioxidant activity of methanolic and aquous extracts were examined by three different methods, namely ferric reducing antioxidant power, cupric reducing antioxidant capacity and 2,2-diphenylpicrylhydrazyl radical scavenging activity. the phenolic constituents were also determined by reverse phase-high performance liquid chromatography. Solid phase microextraction of Teucrium orientale var. glabrescens was analyzed by Gas Chromatography-Flame Ionization Dedector/Mass Spectromerty, Solid-Phase Microextraction (GC-FID/MS, SPME). the antimicrobial activity was studied by agar diffusion method. Extracts showed strong antioxidant and antimicrobial activity and contained large amounts of antioxidant compounds. Rosmarinic acid, p-coumaric acid and p-hydroxybenzoic acid were detected in methanolic extract of plant. Aquous extract was especially effective against Mycobacterium smegmatis. the main chemical classes identified consisted of aldehydes (32.5%), hydrocarbons (29.8%) and monoterpene hydrocarbons (29.8%). Common volatile components of plant detected included nonanal, thuja-2,4 (10)-diene and tetracosane

Phenolic Components and Antioxidant Activity of Prunus spinosa from Gumushane, Turkey

EYUPOGLU, Ozan Emre/0000-0002-4449-0537; Sahin, Huseyin/0000-0002-6018-1494WOS: 000352641900033…KTU Research FundKaradeniz Teknik University [1205]This study was supported by KTU Research Fund (Project No. 1205)