Facultatea de Chimie şi Tehnologie Chimică / Faculty of Chemistry and Chemical Technology

Permanent URI for this communityhttps://msuir.usm.md/handle/123456789/5

Browse

Start date: 2024Subject: search.filters.subject.antioxidant activity

Search Results

Now showing 1 - 4 of 4
  • Thumbnail Image
    Item
    Biogenic ZnO nanoparticles: structural characterisation and bioactivity evaluation [Articol]
    (2025) Pawar, Abhimanyu Parasram; Naktode, Kishor Sudhir; Mungole, Arvind Janardhan; Anga, Srinivas
    Zinc oxide nanoparticles were synthesized via a green route using Nicotiana plumbaginifolia plant extract, serving as a novel bio-reducing and stabilizing agent. Structural analysis through X-ray diffraction confirmed the hexagonal wurtzite crystalline structure, while Fourier-transform infrared spectroscopy and energy-dispersive X-ray spectroscopy affirmed the presence of Zn–O bonds and high purity. Morphological characterization by scanning electron microscopy and transmission electron microscopy revealed spherical nanoparticles with sizes ranging from 16 to 24 nm. The calculated optical band gap was 3.33 eV. A prominent FTIR peak at 480 cm⁻¹ indicated Zn–O stretching vibrations. The Zinc oxide nanoparticles exhibited significant antibacterial activity against Pseudomonas aeruginosa (18 mm), Escherichia coli (19 mm), Klebsiella pneumoniae (19 mm), and Staphylococcus aureus (18 mm) at 100 μL, as evaluated by the well diffusion method. Additionally, the nanoparticles showed strong antioxidant activity, achieving 75.59% DPPH radical scavenging at 250 μg/mL, indicating potential biomedical applications.
  • Thumbnail Image
    Item
    Activitatea antioxidantă a filmelor cu extracte din produse vegetale de Sophora Japonica L. [Articol]
    (CEP USM, 2024) Grigoraș, Carolina; Ciocârlan, Alexandru; Gonţa, Maria
    Plant products of S. japonica, more precisely: flowers, fruits and seeds collected in May and September, respectively, have been conditioned, and the products obtained serve as a source of raw material. The extracts were obtained from the vegetable raw material by maceration, distillation and hydrodistillation using various solvents, with the subsequent incorporation into the filmogenic mixture of chitosan:pectin, to obtain polymeric films. The obtained films were evaluated according to quality indices, thus the appearance, smell and mechanical properties were analyzed, the thickness of the films was measured and antioxidant properties were determined. The prepared biomaterials are uniform, thin, elastic, flexible, have no smell and have a specific color of the composition, manifest an antioxidant activity, but this varies depending on the composition of the prepared films.
  • Thumbnail Image
    Item
    Synthesis and biological activity of n-(4-methoxyphenyl)-2-oxopropanamide 4-phenylthiosemicarbazone and its copper(II) complexes [Articol]
    (CEP USM, 2024) Graur, Ianina; Usataia, Irina; Graur, Vasilii; Tsapkov, Victor; Gulea, Aurelian; Garbuz, Olga; Balan, Greta
    The new N-(4-methoxyphenyl)-2-oxopropanamide 4-phenylthiosemicarbazone (HL) and its 5 copper(II) coordination compounds [Cu(L)X] (X = Cl- (I); Br- (II); NO3- (III); CH3COO- (IV); Cl2CHCOO- (V)) have been synthesized and characterized by elemental analysis, FTIR and NMR spectra. Coordination of 4-phenylthiosemicarbazone HL with the copper(II) atom led to increased antibacterial activity against Staphylococcus aureus and Bacillus cereus. Non-coordinated 4-phenylthiosemicarbazone (HL) showed the highest activity in relation to ABTS•+ cation radicals; its activity is close to that of Trolox, which is used in medicine. The antibacterial and antioxidant activities of the synthesized complexes are influenced by the nature of the acidic residue in their composition.
  • Thumbnail Image
    Item
    Exploring the antioxidant activity of 1-(piperidin-1-yl) propane-1,2-dione 4-phenylthiosemicarbazone and 3d metal coordination compounds with this ligand [Articol]
    (CEP USM, 2024) Graur, Ianina; Maxim, Mihail; Graur, Vasilii; Tsapkov, Victor; Gulea, Aurelian; Garbuz, Olga
    The new 1-(piperidin-1-yl)propane-1,2-dione 4-phenylthiosemicarbazone (HL) and its 7 coordination compounds [Cu(L)X] (X = Br- (I); Cl- (II); NO3 - (III); CH3COO- (IV); Cl2CHCOO- (V)), [Co(L)2]NO3 (VI), [Fe(L)2]NO3 (VII) have been synthesized and characterized by elemental analysis, FTIR, 1H, 13C NMR spectra and molar electric conductibility. For the obtained compounds it was studied the antioxidant activity towards ABTS•+ radical cation. Uncoordinated 4-phenylthiosemicarbazone HL is the most active one with IC50 14.1 μM. Its activity is higher than that of Trolox which is used in medicine as an antioxidant. Among all the synthesized coordination compounds, the iron(III) complex VII showed the greatest activity. The antioxidant activity of metal complexes is influenced by the anion and the nature of the central metal atom.