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

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Author: search.filters.author.Gulea, AurelianEnd date: 2019

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    EFECTUL ANTIBACTERIAN AL UNOR COMPUŞI ORGANICI NOI DIN RÂNDUL SULFANILAMIDELOR
    (2009) Prisacari, Viorel; Buraciova, Svetlana; Țapcov, Victor; Gulea, Aurelian
    Studiul dat se referă la un grup de substanţe sintetice noi din rândul sulfanilamidelor, care manifestă activitate antibacteriană pronunţată faţă de bacteriile grampozitive şi gramnegative şi, totodată, toxicitate joasă.
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    COORDINATION COMPOUNDS OF COBALT, NICKEL, COPPER, AND ZINC WITH N1,N2 -BIS(PYRIDIN-2-YLMETHYLIDENE)BENZENE-1,2-DIAMINE AND ITS DERIVATIVES
    (2014) Pahonțu, Elena; Gulea, Aurelian; Poirier, Donald; Țapcov, Victor
    o-Phenylenediamine reacts with 2-formyl-, 2-acetyl-, or 2-benzoylpyridine in ethanol in the presence of cobalt, nickel, copper, or zinc chlorides to form monomeric complexes ML1-3Cl2·nH2O {M = Co, Ni, Cu, Zn; L1 = N 1,N 2-bis(pyridin-2-ymethylidene)benzene-1,2-diamine, L2 = N 1,N 2-bis(pyridin-2-ylethylidene) benzene-1,2-diamine, L3 = N 1,N 2-bis[phenyl(pyridin-2-yl)methylidene]benzene-1,2-diamine; n = 0-3}. The condensation products (L1-L3) act in the complexes as tetradentate N,N,N,N-ligands. Thermolysis of the complexes occurs in two stages: dehydration (70-95°C) and complete degradation (320-450°C). At concentrations of 10-5-10-7 M, the complexes inhibit in vitro growth and proliferation of HL-60 human promyelocytic leukemia cells.
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    COORDINATION COMPOUNDS OF COPPER AND NICKEL WITH N,N'-[4,4'-(PERFLUORO-1,4-PHENYLENE)BIS(OXY)BIS(4,1-PHENYLENE)]- BIS[2-(PYRIDIN-2-YLMETHYLIDENE)HYDRAZINECARBOTHIOAMIDE] AND ITS DERIVATIVES
    (2014) Pahonțu, Elena; Țapcov, Victor; Poirier, Donald; Gulea, Aurelian
    N,N′-[4,4′-(Perfluoro-1,4-phenylene)bis(oxy)bis(4,1-phenylene)] bis[2-(pyridin-2-ylmethylidene)-hydrazinecarbothioamide] as well as its methyl and phenyl derivatives react with copper and nickel chlorides in ethanol to form coordination compounds. In the products, the hydrazinecarbothioamides act as doubly deprotonated bridging ligands. The prepared complexes have been found to inhibit in vitro the growth and propagation of the myeloid human leukemia HL-60 cancer cells at the 10-5-10-7 mol/L concentration.
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    COORDINATION COMPOUNDS OF COPPER(II) WITH SUBSTITUTED 3-{[(2-HYDROXYPHENYL)METHYLIDENE]AMINO}PROPANE-1,2-DIOLS
    (2013) Gulea, Aurelian; Ciumacov, Iurie; Graur, Vasilii; Țapcov, Victor
    3-{[(2-Hydroxyphenyl)methylidene]amino}propane-1,2-diol, its 5-chloro-,5-bromo-, 5-nitro-, 3-methoxy derivatives, and 3-{[(2-hydroxynaphthyl- 1)methylidene]amino}propane-1,2-diol react with hydrates of copper(II) chloride, bromide and nitrate in ethanol to form coordination compounds Cu(L)X·nH2O. Template condensation reaction between 3-aminopropane-1,2-diol and 2,3-, 2,4- or 2,5-dihydroxybenzaldehyde in the presence of copper(II) nitrate trihydrate results in similar compounds Cu(L)NO3·nH2O. Structure of some of the condensation products was identified by X-ray analysis. Thermolysis of the substances obtained occurs through the dehydration step (70-90 C) and complete thermal decomposition (290-560 C).
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    SYNTHESIS, STRUCTURE, AND ANTIMICROBIAL ACTIVITY OF COPPER(II) CHELATES CONTAINING IMIDAZOLE AND CONDENSATION PRODUCTS OF α-AMINO ACIDS WITH SALICYLALDEHYDE AND ITS DERIVATIVES
    (2013) Gulea, Aurelian; Lozan-Tîrșu, Carolina; Țapcov, Victor; Ciumacov, Iurie; Janno, E.; Rudic, Valeriu
    Salicylaldehyde, 5-bromo- and 5-nitrosalicylaldehydes, 2- hydroxynaphthalene-1-carbaldehyde, and 2,3-, 2,4-, and 2,5- dihydroxybenzaldehydes reacted with glycine, alanine, and phenylalanine in ethanol in the presence of imidazole (Im) and copper(II) acetate hydrate to give copper(II) chelates with the composition Cu(Im)(L) · nH2O (H2L is the condensation product of the above aldehydes with α-amino acids; n = 0-2). The structure of the complex Cu(Im)(L 1) [H2L1 = 2-(2-hydroxybenzylideneamino)acetic acid] was determined by X-ray analysis. The crystalline structure of [2-(2-hydroxybenzylideneamino)acetato](imidazole)copper is formed by polymeric chains of the Cu(Im)(L1) molecules linked through bridging oxygen atoms in the carboxy groups of the Schiff base ligand. The coordination unit has a distorted tetragonal pyramid configuration, where the pyramid base is composed of the phenol and carboxy oxygen atoms, CH=N nitrogen atom in the ligand H2L1 and imidazole nitrogen atom. The oxygen atom in the carboxy group in the neighboring molecule occupies the apical position of the coordination pyramid. The other coordination compounds also have polynuclear structure with the Schiff base H2L acting as doubly deprotonated tridentate O,N,O-ligand and bridging carboxy groups. Thermal decomposition of the complexes includes their dehydration (70-95 C), while complete thermal decomposition occurs at 360-530 C. The synthesized complexes showed selective antimicrobial activity in the concentration range from 75 to 300 μg/ml against a number of standard strains of Staphylococcus aureus and Escherichia coli.
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    SYNTHESIS, STRUCTURE AND PROPERTIES OF COMPLEX COMPOUNDS OF COBALT, NICKEL, COPPER AND ZINC WITH 2-FORMYLPYRIDINE SEMICARBAZONE
    (2009) Gulea, Aurelian; Gînju, Dumitru; Bairac, Natalia; Poirier, Donald; Țapcov, Victor
    2-Formylpyridine semicarbazone L reacts with cobalt, nickel, copper and zinc chlorides, nitrates and perchlorites to form coordination compounds of compositions ML2X2•nH2O (M=Co, Ni, Cu, Zn; X = Cl, NO3, ClO4; L = NC5H 4-CH=N-NH-C(O)-NH2; n = 0, 1) and CuLX2• nH2O (X = Cl, Br, NO3; n = 0-0.5). Complex CuL(NO 3)2 has polynuclear, CuLX2•0.5H 2O (X = Cl, Br), binuclear, and other compounds, mononuclear structures. Azomethine L behaves in them as tridental N,N,O-ligand. Thermolysis of these complexes proceeds through such stages as dehydration (80-95°C), deactivation (145-155°C) and complete theral degradation (170-590°C). Complexes CuLX2•nH2O (X = Cl, NO3; n = 0-0.5) were established to inhibit in vitro the growth and reproduction of 100% of cancer cells of human mieloid leukaemia HL-60 at 10-4 M concentration. At 10-5 M concentration they inhibit only 10% of cells, and at 10-6 M concentration they do not possess anticancer activity.
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    SULFANYLAMIDE-CONTAINING COORDINATION COMPOUNDS OF 3d-ELEMENTS WITH 2,4-PENTANEDIONE BIS-THIOSEMICARBAZONE AND BIS-4-PHENYLTHIOSEMICARBAZONE
    (2008) Gulea, Aurelian; Spînu, S.; Țapcov, Victor; Poirier, Donald
    Thiosemicarbazide and 4-phenylthiosemicarbazide react in ethanol with 2,4-pentanedione in the presence of manganese, cobalt, nickel, copper, and zinc acetates hydrates and streptamin (Sf1), sulfaethidole (Sf 2), and sulfadimidine (Sf3) to form coordination compounds of the composition M(Sf1-3)(L1-2)·nH2O (M = Mn, Co, Ni, Cu, Zn; H2L1 is 2,4-pentanedione bis-thiosemicarbazone, H2L2 is 2,4-pentanedione bis-4-phenylthiosemicarbazone; n = 0-6). All the complexes synthesized are monomeric. Thiosemicarbazones (H2L1 and H 2L2) behave as twice deprotonated S,N,N,S-tetradentate ligands, while sulfanylamides (Sf1-3) act as monodentate ones. Thermolysis of these substances proceeds through the stages of dehydration (65-95°C) and complete thermal decomposition (430-560°C). It is found that the complex [Cu(Sf2)(L1)]·4H2O in the concentration 10-5 M inhibits the growth and fission of 100% cancer cells of the human myeloid leukemia (HL-60).
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    COORDINATION COMPOUNDS OF COPPER WITH 2-FORMYLPYRIDINE 4-(DIMETHYLPHENYL)THIOSEMICARBAZONES
    (2012) Gulea, Aurelian; Lozan-Tîrșu, Carolina; Țapcov, Victor; Corja, Ion; Rudic, Valeriu
    2-Formylpyridine 4-(2,6-dimethylphenyl)-(HL1), 4-(2,5-dimethylphenyl)-(HL2), 4-(3,4-dimethylphenyl)-(HL 3), and 4-(2,4-dimethylphenyl)thiosemicarbazones (HL4) react with copper chloride and nitrate to form coordination compounds CuL 1-4X·nH2O [X = Cl-, NO3 -; n = 1, 2]. All compounds have a polynuclear structure. Azomethines HL1-4 act as the bridging monodeprotonated tridentate N,N,S-ligands. The thermolysis of the complexes includes the dehydration (70-90 C) and total thermal decomposition (350-520 C). The complexes synthesized exhibit a selective antimicrobial activity against a series of standard strains of Staphylococcus aureus and Escherichia coli in the concentration range of 0.009-37.5 μg ml-1
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    SULFANILAMIDE COPPER(II) CHELATES WITH 2-[(2-HYDROXYPHENYL-IMINO)METHYL]PHENOLOM AND 1-[(2-HYDROXYPHENYLIMINO)-METHYL]NAPHTHALEN-2-OL
    (2010) Gulea, Aurelian; Țapcov, Victor; Poirier, Donald; Aruxandei, C.; Pahontu, Elena
    2-[(2-Hydroxyphenylimino)methyl]phenol (H2L1) and 1-[(2-hydroxyphenylimino)methyl]naphthalen- 2-ol (H2L2) reacted with copper(II) acetate hydrate and sulfanilamide (Sf1), sulfathiazole (Sf2), sulfaethidole (Sf3), sulfadiazine (Sf4), and sulfadimidine (Sf5) in ethanol to give mixed-ligand copper chelates with the composition Cu(Sf1-5)(L 1-2) . nH2O (n = 1, 2). All these complexes are monomeric. Salicylaldehyde imines (H2L1 and H2L 2) behave as doubly deprotonated tridentate O,N,O ligands, whereas sulfanilamides (Sf1-5) are unidentate ligands. Thermolysis of the synthesized complexes includes dehydration at 70-90°C, followed by complete thermal decomposition (290-380°C). The complexes [Cu(Sf1)(L 1)] . 2H2O and [Cu(Sf3)(L1)] . H2O at a concentration of 10-4 M inhibited growth and reproduction of 100% of human myeloid leukemia cells (HL-60). The inhibitory effect was 90 and 75%, respectively, at a concentration of 10-5 M, whereas no antitumor activity was observed at a concentration of 10-6 M.
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    COORDINATION COMPOUNDS OF COBALT, NICKEL, COPPER, AND ZINC WITH 2-BROMO-3-PHENYLPROPENAL BENZOYLHYDRAZONE AND THIOSEMICARBAZONE
    (2009) Samusi, Nina; Ciumacov, Iurie; Țapcov, Victor; Bocelli, Gabrielle; Simonov, Iurie; Gulea, Aurelian
    By X-ray structural analysis the crystal structure of 2-bromo-3- phenylpropenal benzoylhydrazone (HL) was determined. The molecule is not flat. In the crystal the HL molecules form infinite chains with reciprocal van der Waals interaction. 2-Bromo-3-phenylpropenal hydrazone (HL) and thiosemicarbazone (HL') react with cobalt, nickel, copper and zinc chlorides, nitrates and acetates to form coordination compounds of the composition Cu(HL)(L)2 [HL = C6H5-CH=CBr-CH=N-NH-C(O)-C6H 5], MX2•2 HL'•nH2O [M = Co, Ni, Cu, Zn; X = Cl, NO3, HL' = C6H5-CH=CBr-CH=N-NH-C(S) -NH2; n = 0-3], MX2•HL•n H2O [M = Ni, Cu; n = 0, 1], and ML'2•nH2O [M = Co, Ni, Zn; n = 0-3]. The same reactions in the presence of amines (A = C5H 5N, 2-CH3C5H4N, 3-CH 3C5H4N, 4-CH3C5H 4N) afford complexes of the composition CuALCl and MALX•n H 2O [M = Cu, Ni; X = Cl, NO3; n = 0-2]. Structure of the coordination node in the amine-containing copper derivatives is polynuclear, in complexes Cu(HL)(L)2 is octahedral, in other compounds it is tetrahedral. The azomethines (HL and HL') in these complexes behave as bidentate N,O and N,S ligands. Thermolysis of the complexes includes a step of dehydration (60-90°C) and complete thermal decomposition (430-590°C).