Synthesis, characterization, and biological properties of oxidovanadium(IV) complexes of acetylsalicylhydroxamic acid (N-acetyloxy-2-hydroxybenzamide) as potential antimicrobials

New oxidovanadium(IV) complexes of composition [VO(AcSHA)2] 1 and [VO(acac)(AcSHA)] 2 are synthesized by reactions of VOSO4.5H2O and [VO(acac)2] with acetylsalicylhydroxamic acid AcSH2A (C6H4(OH)(CONHOCOCH3)) in a 1:2 molar ratio in absolute ethanol. The compounds are characterized by the Fourier-transform infrared spectroscopy, ultraviolet–visible spectroscopy, electron spin resonance, and mass spectrometry along with elemental analyses, molar conductivity, and magnetic moment measurements. The infrared spectra of the complexes suggest bonding through carbonyl and phenolic oxygen atoms (O,O coordination). The magnetic moment, electron spin resonance, and mass spectra of the complexes indicate that both exist as monomers, and a distorted square pyramidal geometry around vanadium is proposed. The thermal behavior of the complexes is studied by thermogravimetry and differential thermal analysis techniques under an N2 atmosphere, yielding VO2 as the decomposition product. The in vitro antimicrobial assays against pathogenic Gram-positive bacteria, Gram-negative bacteria, and fungi (minimum inhibitory concentration method) show the appreciable antimicrobial potential relative to the respective standard drugs, tetracycline hydrochloride, and fluconazole.

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Electron spin resonance observation of the photooxidation of hydrated chlorophyll a dimers by water. In vitro photochemical characterization of reaction centers in photosynthesis

Journal of the American Chemical Society ◽

10.1021/ja00470a043 ◽

1978 ◽

Vol 100 (2) ◽

pp. 619-621 ◽

Cited By ~ 13

Author(s):

F. K. Fong ◽

A. J. Hoff ◽

F. A. Brinkman

Keyword(s):

Electron Spin Resonance ◽

Chlorophyll A ◽

Electron Spin ◽

Reaction Centers ◽

Spin Resonance

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ESR and Optical Studies on the Interaction between Cu(II) and Pepsin

Zeitschrift für Naturforschung C ◽

10.1515/znc-1978-5-603 ◽

1978 ◽

Vol 33 (5-6) ◽

pp. 321-325 ◽

Cited By ~ 1

Author(s):

L. Sportelli ◽

H. Neubacher ◽

W. Lohmann

Keyword(s):

Aqueous Solution ◽

Electron Spin Resonance ◽

Reaction Time ◽

Conformational Change ◽

Optical Spectroscopy ◽

Electron Spin ◽

Molar Ratio ◽

Optical Studies ◽

Spin Resonance

Abstract The interaction of Cu (II) with the protein pepsin has been investigated by means of electron spin resonance (ESR) and optical spectroscopy. Depending on the molar ratio of Cu(II) and pepsin in aqueous solution two different complexes are formed. A third complex can be detected after a reaction time of several days, attributed to a complex with a conformationally changed pepsin. The presence of inhibitors 1,2-epoxy-3-phenoxypropane (EPP) or diazoacetyl-ethylester (DAE) seems to hinder the conformational change. The structure of the three complexes is discussed.

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Pyramidal geometry of the tervalent carbon atom of the norbornadien-7-yl radical; electron spin resonance study

Journal of the Chemical Society Chemical Communications ◽

10.1039/c39780000804 ◽

1978 ◽

pp. 804 ◽

Cited By ~ 4

Author(s):

Yoshio Sugiyama ◽

Takashi Kawamura ◽

Teijiro Yonezawa

Keyword(s):

Electron Spin Resonance ◽

Carbon Atom ◽

Electron Spin ◽

Electron Spin Resonance Study ◽

Pyramidal Geometry ◽

Spin Resonance ◽

Spin Resonance Study

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Synthesis and electron spin resonance studies of a Co(II) complex with a tetradentate macrocyclic Schiff base ligand

Canadian Journal of Chemistry ◽

10.1139/v77-012 ◽

1977 ◽

Vol 55 (1) ◽

pp. 70-75 ◽

Cited By ~ 6

Author(s):

Amikam Reuveni ◽

Vincenzo Malatesta ◽

Bruce R. McGarvey

Keyword(s):

Electron Spin Resonance ◽

Electron Spin ◽

Ground State ◽

Molar Ratio ◽

Lewis Bases ◽

Spin Resonance ◽

Frozen Solutions ◽

Hamiltonian Parameters ◽

Simulation Of Spectra ◽

Macrocyclic Schiff Base

The synthesis, physical properties, and electron spin resonance of frozen solutions of CoTAAB(NO3)2 (TAAB = tetrabenzo[b,f,j,n] [1,5,9,13]tetraazacyclohexadecine) are reported. The spin Hamiltonian parameters were elucidated by simulation of spectra assuming axial g and 59Co hyperfine tensors and including nuclear quadrupole and Zeeman contributions. Electron spin resonance spectra in solvents such as methanol, acetone, and dimethylformamide are typical for a low spin complex (S = 1/2) and are nearly identical with [Formula: see text] and [Formula: see text]. In pyridine and quinoline a complex with a molar ratio solvent/ligand of 1:1 is formed with the solvent which gives [Formula: see text]and [Formula: see text] much closer to [Formula: see text]. In strong Lewis bases, such as piperidine, a 2:1 complex is formed and no esr signal is found. Evidence is presented to show that these 2:1 complexes with strong Lewis bases are S = 1/2 complexes with a low lying S = 3/2 state that is partially populated at room temperatures. This behaviour is accounted for in terms of a theory derived for a 2A1 ground state with a low lying quartet state which could become the ground state in strong basic solvents.

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Sumatriptan Scavenges Superoxide, Hydroxyl, and Nitric Oxide Radicals: In Vitro Electron Spin Resonance Study

Headache The Journal of Head and Face Pain ◽

10.1046/j.1526-4610.2002.02208.x ◽

2002 ◽

Vol 42 (9) ◽

pp. 888-892 ◽

Cited By ~ 22

Author(s):

Yukio Ikeda ◽

Hiroyuki Jimbo ◽

Motohiko Shimazu ◽

Kazue Satoh

Keyword(s):

Nitric Oxide ◽

Electron Spin Resonance ◽

Electron Spin ◽

Electron Spin Resonance Study ◽

Spin Resonance ◽

Spin Resonance Study

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Synthesis, Characterisation, and Biological Properties of Oxidovanadium(IV) 3,5-Dinitrosalicylhydroxamate Complexes

Australian Journal of Chemistry ◽

10.1071/ch19486 ◽

2020 ◽

Vol 73 (1) ◽

pp. 61

Author(s):

Bhanu Priya ◽

Abhishek Kumar ◽

Neeraj Sharma

Keyword(s):

Magnetic Moment ◽

Pathogenic Bacteria ◽

Electrochemical Behaviour ◽

Radical Scavenging ◽

Biological Properties ◽

Pyramidal Geometry ◽

Elemental Analyses ◽

Ft Ir ◽

Bacteria And Fungi ◽

Thermal Analysis Techniques

The new oxidovanadium(iv) complexes of composition [VO(3,5(NO2)2C6H2(OH)CONHO)2] 1 and [VO(acac)(3,5(NO2)2C6H2(OH)CONHO)] 2 (where acac=(CH3COCHCOCH3)–] have been synthesised by the reactions of VOSO4·5H2O and [VO(acac)2] with potassium 3,5-dinitrosalicylhydroxamate (3,5-(NO2)2SHK) and characterised by elemental analyses, molar conductivity, magnetic moment measurements and FT-IR, UV-vis, and electron spin resonance (ESR) spectroscopies and mass spectrometry. Infrared spectra of complexes have indicated bonding through oxygen atoms of carbonyl and hydroxamic groups (O,O coordination). The magnetic moment, ESR, and mass spectra of the complexes suggested their monomeric nature, and a distorted square-pyramidal geometry around the vanadium has tentatively been proposed. The electrochemical behaviour of 1 and 2 has been studied by cyclic voltammetry. Thermal behaviour of the complexes studied by thermogravimetric and differential thermal analysis techniques has yielded VO2 as the decomposition product. The invitro antimicrobial activity of the ligand and complexes has been assayed against pathogenic bacteria and fungi by the minimum inhibitory concentration (MIC) method. The invitro antioxidant activity of the complexes has been determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging method.

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