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

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Author: search.filters.author.Graur, VasiliiStart date: 2018

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    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.
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    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.
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    Synthesis, Structure, and Biological Activity of Mixed-Ligand Amine-Containing Copper(II) Coordination Compounds with 2-(2-Hydroxybenzylidene)-N-(prop-2-en-1-yl)hydrazinecarbothioamide [Articol]
    (2021) Gulea, Aurelian; Graur, Vasilii; Ulchina, Ianina; Bouroș, Pavlina; Smaglii, Vadim; Garbuz, Olga; Țapcov, Victor
    Сopper(II) nitrate reacts in ethanol with 2-(2-hydroxybenzylidene)-N-(prop-2-en-1-yl)hydrazinecarbothioamide H2L in an 1 : 1 molar ratio to form the coordination compound Cu(HL)NO3·H2O. The introduction of amines [imidazole (Im), 3,5-dibromopyridine (3,5-Br2Py), and 4-methylpyridine (4-Pic)] into the reaction mixture in a molar ratio 1 : 1 : 2 leads to the formation of CuA(HL)NO3·nH2O [A = Im, 3,5-Br2Py, 4-Pic; n = 0, 3] complexes. The structure of the obtained compounds was determined by X-ray structural analysis. The synthesized complexes exhibit antimicrobial, antifungal, antioxidant, and anticancer activities.
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    Synthesis, Structure, and Biological Activity of Copper(II), Nickel(II), Cobalt(III), and Iron(III) Coordination Compounds with 2-{2-[(Prop-2-en-1-yl)carbamothioyl]hydrazinylidene}propanoic Acid [Articol]
    (2020) Gulea, Aurelian; Graur, Vasilii; Diurici, E.; Ulchina, Ianina; Bouroș, Pavlina; Balan, Greta; Burduniuc, Olga; Țapcov, Victor; Rudic, Valeriu
    2-Oxopropanoic acid reacts in ethanol with N-(prop-2-en-1-yl)hydrazinecarbothioamide in a 1 : 1 mole ratio to form thiosemicarbazone H2L. Coordination compounds Cu(HL)X [X = Cl–, Br–, NO3–], Cu(H2O)(L), Ni(HL)2, Co(HL)2X [X = Cl–, Br–], and Fe(HL)2X [X = NO3–, Br–] are formed in the reactions of H2L with copper(II), nickel(II), cobalt(II), and iron(III) salts. The reactions of Cu(H2O)(L) with imidazole (Im) and 3,4-dimethylpyridine (3,4-Lut) result in mixed-ligand complexes Cu(A)(L) [A = Im, 3,4-Lut]. The structures of two copper complexes were determined by single crystal X-ray diffraction analysis. The synthesized complexes exhibit selective antimicrobial and antifungal activity in the concentration range of 15.62–1000 μg/mL. The introduction of amines into the inner sphere of copper complexes leads to an increase in the antimicrobial activity.
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    Synthesis, Structure and Biological Activity of Coordination Compounds of Copper, Nickel, Cobalt, and Iron with Ethyl N'-(2-Hydroxybenzylidene)-N-prop-2-en-1-ylcarbamohydrazonothioate [Articol]
    (2020) Gulea, Aurelian; Usataia, Irina; Graur, Vasilii; Ciumacov, Iurie; Petrenko, Peter; Balan, Greta; Burduniuc, Olga; Țapcov, Victor; Rudic, Valeriu
    N-(Prop-2-en-1-yl)hydrazonocarbothioamide reacts with iodoethane in methanol with further addition of 2-hydroxybenzaldehyde to form hydroiodide of carbamohydrazonothioate (HL·HI). The coordination compounds were obtained by interaction of HL or HL·HI with copper, nickel, cobalt and iron salts CuLХ·nH2O [X = Cl–, Br–, NO3–; n = 0–1], Ni(L)2·HI·CH3OH, Сo(L)2X [X = I–, NO3–] and Fe(L)2NO3. The structures of three complexes were established by single crystal X-ray analysis. The synthesized complexes exhibit selective antimicrobial and antifungal activity against a series of standard microorganisms and fungi in the concentration range of 30–500 μg/mL. In addition, nickel and iron complexes selectively inhibit the growth and proliferation of cancer cells and do not adversely affect normal cells.
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    Nickel (II) Complexes with Pentane-2,4-dione Bis(4-allylthiosemicarbazone) [Articol]
    (2020) Gulea, Aurelian; Graur, Vasilii; Ciumacov, Iurie; Petrenko, Peter; Garbuz, Olga; Țapcov, Victor; Gudumac, Valentin
    Reaction of pentane-2,4-dione with N-(prop-2-en-1-yl)hydrazinecarbothioamide at a 1: 2 molar ratio in ethanol resulted in the formation of a pyrazole derivative. The latter reacted with nickel perchlorate at a 1: 1 molar ratio to form the nickel complex with pentane-2,4-dione bis(4-allylthiosemicarbazone). The same type of nickel complex was obtained as a result of N-(prop-2-en-1-yl)hydrazinecarbothioamide reaction with pentane-2,4-dione and nickel nitrate at a 2: 1: 1 molar ratio. Antimicrobial, antifungal, antioxidant, and anticancer activities of the obtained compounds were studied.
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    Synthesis, Structure, and Biological Activity of Copper and Cobalt Coordination Compounds with Substituted 2-(2-Hydroxybenzylidene)-N-(prop-2-en-1-yl) hydrazinecarbothioamides [Articol]
    (2019) Gulea, Aurelian; Graur, Vasilii; Ciumacov, Iurie; Petrenko, Peter A.; Balan, Greta; Burduniuc, Olga; Țapcov, Victor; Rudic, Valeriu
    The reaction of N-(prop-2-en-1-yl)hydrazinecarbothioamide with substituted 2-hydroxybenzaldehydes afforded the corresponding Schiff bases which were used as ligands to obtain copper and cobalt coordination compounds Cu(NL1–6)X · n H2O (X = Cl−, NO3−; n = 0–3), Co(HL2)2NO3, and Co(NL6)2Cl. The structure of the isolated complexes was determined by NMR spectroscopy and X-ray analysis. The complexes were tested for antimicrobial and antifungal activity against S. aureus, E. coli, and yeast-like fungi. Inhibitory effect of the initial thioamides and their complexes against human myeloid leukemia HL-60 cancer cell line was also studied.
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    Introducing N-Heteroaromatic Bases into Copper(II) Thiosemicarbazon Complexes: A Way to Change their Biological Activity [Articol]
    (2022) Ulchina, Ianina; Graur, Vasilii; Țapcov, Victor; Ciumacov, Iurie; Garbuz, Olga; Burduniuc, Olga; Ceban, Emil; Gulea, Aurelian
    Three new copper(II) complexes, [Cu(1,10-Phen)(L)] (1), [Cu(2,2’- Bpy)(L)] (2) and [Cu(3,4-Lut)(L)] (3), where H2L=2-[(2,4- dihydroxyphenyl)methylidene]-N-(prop-2-en-1-yl)hydrazine-1- carbothioamide, 1,10-Phen=1,10-phenanthroline, 2,2’-Bpy= 2,2’-bipyridine, 3,4-Lut=3,4-lutidine, have been synthesized and characterized by elemental analysis, FTIR spectroscopy and single crystal X-ray crystallography (1, 2). All compounds are mononuclear. The introduction of a monodentate N-heteroaromatic base (3,4-dimethylpyridine) has led to a significant increase of antimicrobial activity against Gram-negative Escherichia coli and antifungal activity against Candida albicans compared to the pro-ligand and the precursor complex [Cu- (L)H2O]. The introduction of bidentate N-heteroaromatic bases did not lead to such increase of antimicrobial and antifungal activities. Moreover, complex 3 surpasses the inhibitory activity of tetracycline toward Enterobacter cloacae and the inhibitory activity of fluconazole toward Candida parapsilosis and Cryptococcus neoformans. The study of antioxidant activity against cation radicals ABTS* + showed that complexes 1–3 are more active than Trolox, but only introduction of the monodentate Nheteroaromatic base (3,4-dimethylpyridine) led to the increase of antioxidant properties compared to the precursor complex.
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    Novel 2-formylpyridine 4-allyl-S-methylisothiosemicarbazone and Zn(II), Cu(II), Ni(II) and Co(III) complexes: Synthesis, characterization, crystal structure, antioxidant, antimicrobial and antiproliferative activity [Articol]
    (2019) Balan, Greta; Usataia, Irina; Graur, Vasilii; Ciumacov, Iurie; Petrenko, Peter; Gudumac, Valentin; Gulea, Aurelian; Pahonțu, Elena; Burduniuc, Olga
    New zinc (II), copper (II), nickel (II) and cobalt (III) complexes, [Zn (HL)2]I2 (1), [Cu (HL)Cl2] (2), [Cu (HL)Br2] (3), [Cu (HL)(H2O)2](ClO4)2 (4), [Ni (HL)2]I2·H2O (5), [Co(L)2]Cl (6), [Co(L)2]NO3 (7), [Co(L)2]I·[Co(L)2](I3) (8) were obtained with 2-formylpyridine 4-allyl-S-methylisothiosemicarbazone (HL). The isothiosemicarbazone ligand was characterized by NMR (1H and 13C), IR spectroscopy and X-ray diffraction. All the complexes were characterized by elemental analysis, IR, UV–Vis, ESI-MS spectroscopy, molar conductivity, magnetic susceptibility measurements. X-ray diffraction analysis on the monocrystal and powder elucidated the structure of the complexes 1, 5, 7 and 8. The ligand and the complexes were tested for their antioxidant and antimicrobial activity against Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae and Candida albicans. Also, the antiproliferative properties of these compounds on human leukemia HL-60, human cervical epithelial HeLa, human epithelial pancreatic adenocarcinoma BxPC-3, human muscle rhabdomyosarcoma spindle, large multinucleated RD cells and normal MDCK cells have been investigated. The nickel complex 5 and cobalt complexes 6, 7 showed promising antiproliferative activity and low toxicity.
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    Synthesis, characterization, crystal structure of novel Cu (II), Co (III), Fe (III) and Cr (III) complexes with 2-hydroxybenzaldehyde-4-allyl-S-methylisothiosemicarbazone: Antimicrobial, antioxidant and in vitro antiproliferative activity [Articol]
    (2018) Pahonțu, Elena; Usataia, Irina; Graur, Vasilii; Ciumacov, Iurie; Petrenko, Peter; Gudumac, Valentin; Gulea, Aurelian
    2-Hydroxybenzaldehyde-4-allyl-S-methylisothiosemicarbazone and Cu (II), Co (III), Fe (III) and Cr (III) complexes were synthesized and characterized. The new obtained compounds were investigated by elemental analysis, magnetic susceptibility measurements, molar electric conductivity, IR, 1H NMR, 13C NMR, UV–Vis spectroscopy. In addition, the structure of the ligand and six complexes has been determined by single-crystal X-ray diffraction analysis. The Cu atom in complex 3 is penta-coordinated in a distorted square–pyramidal coordination geometry, while the metals in complexes 5–9 are in a distorted octahedral environment. For all compounds the antimicrobial activity was studied on a series of standard strains, such as Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, Salmonella abony and Candida albicans. The in vitro antiproliferative activity of the ligand and complexes was screened on human leukemia HL-60 cells, human cervical epithelial HeLa cells, human epithelial pancreatic adenocarcinoma BxPC-3 cells, human muscle rhabdomyosarcoma spindle and large multinucleated RD cells. The primary screening on a wider series of cancer cells showed that copper coordination compound 2 manifests high activity towards HeLa, BxPC-3 and RD cancer cells, which is three–six times higher than the activity of doxorubicin. The selectivity index that is the ratio between the IC50 value for the normal MDCK cells and IC50 values for the cancer cells varies in the range 2.44–21.17. This index is 5.5–11 times higher for the copper coordination compound 2 than for the doxorubicin. Cr (III), Fe (III) and Co (III) coordination compounds 6–9 manifest high antioxidant activity towards ABTS•+ that exceeds 47–67 times the activity of Trolox.