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

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Author: search.filters.author.Țapcov, VictorStart date: 2019

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    Synthesis, characterization, andbiological properties of the copper(II) complexes with novellig and: N-[4-({2-[1-(pyridin2-yl)ethylidene] hydrazinecarbothioyl}amino) phenyl] acetamide [Articol]
    (2023) Rusnac, Roman; Garbuz, Olga; Ciumacov, Iurie; Țapcov, Victor; Hureau, Christelle; Istrati, Dorin; Gulea, Aurelian
    For the first time, a thiosemicarbazone-type ligand containing a paracetamol structural unit was synthesized. Five new coordination compounds based on copper(II) salts: [Cu(L)CH3COO] (1), [{Cu(L)Cl}2]·H2O (2), [Cu(L)H2O·DMF]NO3 (3), [Cu(L)Br] (4), [Cu(L)H2O]ClO4 (5), were obtained, where HL is N-[4-({2-[1-(pyridin-2-yl)ethylidene]hydrazinecarbothioyl}amino)phenyl]acetamide. The new HL was characterized by NMR, FTIR, spectroscopy, and X-ray crystallography. All copper(II) coordination compounds were characterized by elemental analysis, FTIR, EPR spectroscopy, and molar electrical conductivity. Furthermore, single crystal X-ray diffraction analysis elucidated the structures of thiosemicarbazone HL as well as complexes 1–3. All compounds were tested for antimicrobial, antifungal, and antioxidant activities, and their toxicity to Daphnia magna was studied. Biological evaluation has revealed that most of the synthesized compounds demonstrate promising antibacterial, antifungal, and antioxidant activities. In many cases, their antibacterial/antifungal activity is comparable to that of certain drugs used in medicine for these purposes, and in some cases, even surpasses them. HL and complexes 2–5 exhibit antioxidant activity that surpasses that of Trolox. Furthermore, HL and complex 2 display virtually no toxicity to D. magna.
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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 Coordination Compounds of Cobalt(II), Nickel(II), and Copper(II) with N-(Methoxyphenyl)-2-[(5-nitrofuryl)methylene]hydrazine Carbothioamides [Articol]
    (2019) Gulea, Aurelian; Mitchevici, N.; Ciumacov, Iurie; Petrenko, Peter; Balan, Greta; Burduniuc, Olga; Țapcov, Victor
    4-(2-Methoxyphenyl)-, 4-(3-methoxyphenyl)-, and 4-(4-memoxyphenyl)-2-[(5-mttofuryl)methylene]-hydrazine carboxamide (HL1–3) react with hydrates of cobalt (nickel, copper) chloride (nitrate, acetate) with the formation of the M(HL1–3)2X2 (M = Co2+, Ni2+, Cu2+; X = Cl−, NO3−) and M(L1–3)2 (M = Ni2+, Cu2+) coordination compounds. Structure of the obtained compounds has been studied by means of X-ray diffraction analysis. Their antimicrobial and antifungal activity towards a series of Staphylococcus aureus, Escherichia coli, and yeast-like fungi standard strains has been investigated.
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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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    Synthesis, Structure, and Biologic Activity of Some Copper, Nickel, Cobalt, and Zinc Complexes with 2-Formylpyridine N4-Allylthiosemicarbazone [Articol]
    (2022) Graur, Vasilii; Ciumacov, Iurie; Garbuz, Olga; Hureau, Christelle; Țapcov, Victor; Gulea, Aurelian
    A series of zinc(II) ([Zn(H2O)(L)Cl] (1)), copper (II) ([Cu(L)Cl] (2), [Cu(L)Br] (3), [Cu2(L)2(CH3COO)2]·4H2O (4)), nickel(II) ([Ni(HL)2]Cl2·H2O (5)), and cobalt(III) ([Co(L)2]Cl (6)) complexes were obtained with 2-formylpyridine N4-allylthiosemicarbazone (HL). In addition another two thiosemicarbazones (3-formylpyridine N4-allylthiosemicarbazone (HLa) and 4-formylpyridine N4-allylthiosemicarbazone (HLb)) have been obtained. The synthesized thiosemicarbazones have been studied using 1H and 13C NMR spectroscopy, IR spectroscopy, and X-ray diffraction analysis. The composition and structure of complexes were studied using elemental analysis, IR and UV-Vis spectroscopies, molar conductivity, and magnetic susceptibility measurements. Single crystal X-ray diffraction analysis elucidated the structure of thiosemicarbazones HL, HLa, and HLb, as well as complexes 4 and 5. The antiproliferative properties of these compounds toward a series of cancer cell lines (HL-60, HeLa, BxPC-3, RD) and a normal cell line (MDCK) have been investigated. The nickel complex shows high selectivity (SI > 1000) toward HL-60 cell line and is the least toxic. The zinc complex shows the highest selectivity toward RD cell line (SI = 640). The copper complexes (2-4) are the most active molecular inhibitors of proliferation of cancer cells, but exhibit not such a high selectivity and are significantly more toxic. Zinc and copper complexes manifest high antibacterial activity. It was found that calculated at B3LYP level of theory different reactivity descriptors of studied compounds strongly correlate with their biological activity.
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    Crystal structures of [N′-(2- oxidobenzylidene)-N-(prop-2-en-1-yl carbamohydrazonothioato(2-)](1,10- phenanthroline)copper and [N′-(2- oxidobenzylidene)-N-(prop-2-)- en-1-yl)- carbamohydrazonothioato(2-)](2,2′- bipyridine)copper hemihydrates [Articol]
    (2022) Ciumacov, Iurie; Graur, Vasilii; Ulchina, Ianina; Smaglii, Vadim; Gulea, Aurelian; Garbuz, Olga; Țapcov, Victor
    The crystal structures and biological properties of [N′-(2-oxidobenzylidene)-N-(prop-2-en-1-yl)-carbamohydrazonothioato(2-)](1,10-phenanthroline)copper hemihydrate [Cu(1,10-Phen)(L)]·0.5H2O (I) and [N′-(2-oxidobenzylidene)-N-(prop-2-en-1-yl)-carbamohydrazonothioato(2-)](2,2′-bipyridine)copper hemihydrate [Cu(2,2′-BPy)(L)]·0.5H2O (II), where Н2L is 2-(2-hydroxybenzylidene)-N-(prop-2-en-1-yl)hydrazinecarbothioamide, are determined. The asymmetric unit of the unit cell in the crystal structures of I and II contains a copper complex with bidentate amine and a ligand coordinated by the azomethine nitrogen atom, the deprotonated phenolic oxygen atom, and the sulfur atom in the thiol form. The coordination polyhedron of the copper atom in compounds I and II is a distorted tetragonal pyramid. Obtained coordination compounds I and II exhibit antimicrobial and antifungal activities and have minimum inhibitory concentration and bactericidal concentration values in a range of 1.5-500 µg/mL. The study of the antioxidant activity shows that compounds I and II are less active than uncoordinated thiosemicarbazone H2L, but more active than trolox used in medical practice.