Browsing by Author "Chumakov, Yurii"

Now showing 1 - 14 of 14

COMPOUNDS REMOVED FROM THE CONDENSATION REACTION BETWEEN 2 - ACETYLPYRIDINE AND 2 - FORMYLPYRIDINE. SYNTHESIS, CRYSTAL STRUCTURE AND BIOLOGICAL EVALUATION
(Institutul de Chimie al AŞM, 2020) Rusnac, Roman; Botnaru, Maria; Barba, Nicanor; Petrenko, Peter; Chumakov, Yurii; Gulea, Aurelian
The research is devoted to the study of unexpected products that formed as a result of the condensation reaction between 2-acetylpyridine and 2-formylpyridine under the Claisen-Schmidt reaction conditions. The structure of the compoundswas determined and confirmed using FTIR, 1H and 13 C NMR spectroscopy, and X-ray diffraction technique. As a result, a sequence of reactions leading to the following compounds has been proposed: 1,3-bis(pyridin -2-yl)prop-2-en-1-one (3); 1,3,5-tri(pyridin-2-yl)pentane-1,5-dione (4); (2,4-dihydroxy -2,4,6-tri(pyridin-2-yl)cyclohexyl)(pyridin-2-yl)methanone (5) and (4-hydroxy-2,4,6 -tri(pyridin-2-yl)cyclohexane-1,3-diyl)bis(pyridin-2-ylmethanone) (6) as well as2- formylpyridine (1) and 2-acetylpyridine (2). The plausible mechanisms of these chemical transformations and synthetic methods for obtaining substituted cyclohexanol derivatives are also presented. The synthesized compounds were tested for antimicrobial and antioxidant activity. The obtained results show that the compounds 4-6have moderate antifungal activity. The activity of compound 6is nine times higher towards Cryptococcus neoformans than the activity of Nistatinthat is used in medical practice. The present experimental results show that compound 6has potential application in antibacterial and antifungal areas.
THE CRYSTAL STRUCTURE AND ANTIMICROBIAL ACTIVITY OF BIS[METHYLN ’ -(2-HYDROXOBENZYLIDENE)-N-PROP-2-EN-1- YLCARBAMOHYDRAZONOTHIOATE]CHROMIUM(III) NITRATE
(Academia de Ştiinţe a Moldovei, 2015) Petrenko, Peter A.; Graur, Vasilii О.; Chumakov, Yurii; Truhina, Irina; Tsapkov, Victor I.; Prisakari, Viorel I.; Zariciuc, Elena; Rudic, Valeriu; Gulea, Aurelian
THE CRYSTAL STRUCTURE AND ANTITUMOR ACTIVITY OF 1,6-DINITRATO-BIS[2-(5-METHYLSULFANYL)-4-(PROP-2-EN-1-YL)-4- -(1,2,4-TRIAZOL-3-YL)PYRIDINE]COPPER
(Academia de Ştiinţe a Moldovei, 2015) Petrenko, Peter A.; Graur, Vasilii О.; Chumakov, Yurii; Truhina, Irina; Tsapkov, Victor I.; Poirier, Donald; Gulea, Aurelian
CRYSTAL STRUCTURES OF COPPER (II) CHLORIDE, NITRATE AND SULPHATE COMPLEXES WITH THIOSEMICARBAZONE PYRIDINE-2-CARBOXYALDEHYDE
(Academia de Ştiinţe a Moldovei, 2006) Chumakov, Yurii; Jeanneau, Erwann; Bejenari, Nadejda; Tsapkov, Victor I; Gulea, Aurelian
Thiosemicarbazones of different aldehydes and ketones take a special place among the organic ligands because of a variety of their donor atoms and ability to change the dentantity depending on initial reagents and conditions of their interaction reactions. It is known that the thiosemicarbazone of pyridine-2-carboxyaldehyde (L) possesses the biological activity and belongs to Schiff bases. It has an ability to react with ions of metals by forming chelate coordination compounds. In many cases, the biological activity of medicines is consistent with their complex ability. In this connection the coordination compounds of CuLSO4 (I), Cu(L-H)Cl (II) and Cu(L-H)NO3 (III) have been synthesized and studied by X-ray method. Crystal I forms a Zwitter-ionic structure where related by symmetry center complexes of CuL are joined by SO4-groups in dimers via oxygen atoms. In crystal structure of II the complexes are also consolidated into dimers due to the center of symmetry by the S atom of the thioamide group of organic ligand. In I and II the coordination polyhedron of the central atom is an extended tetragonal pyramid. In I the base of pyramid consists of donor pyridine and azomethine N and also S and O atoms of SO4-group while in II the base of a pyramid is formed by the donor atoms and Cl atom. The vertexes of pyramids are occupied by the oxygen atom of neighboring SO4-group (in I) and S atom of adjacent complex connected with the initial complex by symmetry center (in II). In the crystal III form the infinite polymeric chains along c direction due to the glide plane. The coordination polyhedron of the copper atom is an extended tetragonal bipyramid. Both axial vertexes of bipyramid are occupied by the oxygen atoms of NO3- and amidic nitrogen groups. The base of bipyramid consists of donor pyridine and azomethine N and S atoms and also amidic N atom of adjacent complex connected with the initial complex by glide plane. In turn the amidic N atoms of initial complex are located in the basis of coordination bipyramid of neighboring complex, thus forming the infinite polymeric chain along c direction.
CRYSTAL STRUCTURES OF COPPER (II) COMPLEXES WITH 5-CHLORINE- AND 5-BROMINE-SUBSTITUTED N-ETHANOLSALICYLIDENIMINES
(Academia de Ştiinţe a Moldovei, 2006) Chumakov, Yurii; Tsapkov, Victor I.; Bocelli, Gabriele; Antosyak, B.; Gulea, Aurelian
The condensation products of alcanolimines with aldehydes and ketons form the biologically active coordination compounds with ions of transition metals differing in composition, structure and properties. In this respect, the synthesis of biometal complexes with similar ligands and investigations of the structural features of these compounds are of great interest from scientific and practical standpoints. Therefore the crystal structures of bis-{4-bromo-2-[(2-hydroxy-ethylamine)methyl]phenole}copper (I), bis-{4-chloro-2-[(2-hydroxy-ethylamine)-methyl]phenole}copper (II) have been studied. Crystals of I are monoclinic, a = 13.237(3), b = 4.589(1), c = 21.010(4) Å, space group P21/c, Z =2, R = 0.036. Crystals of II are also monoclinic, a = 4.994 (1), b = 17.034 (3), c = 10.723 (2) Å, space group P21/n, Z =2, R = 0.066. In I and II the metal atom is situated at symmetry center. In I the copper atom coordinates two singly deprotonated bidentate molecules of 4-bromo-2-[(2-hydroxy-ethylamine)-methyl]phenol through the phenolic oxygen atoms and azomethine nitrogen atoms. The donor atoms form the distortion square around the central atom due to center of symmetry. In II the copper atom coordinates two singly deprotonated bidentate molecules of 4-chloro-2-[(2-hydroxy-ethylamine)-methyl]phenol through the phenolic oxygen atoms and azomethine nitrogen atoms. The coordination polyhedron of the central atom is an extended tetragonal bipyramid with the phenolic oxygen atoms and azomethine nitrogen atoms in its base. Both axial vertexes of bipyramid are occupied by the oxygen atoms of aminealcohol groups of adjacent complexes connected with the initial complex by symmetry center. In turn the oxygen atoms of amine alcohol groups of initial complex are located in coordination bipyramid apexes of neighboring complexes and thus forming the infinite polymeric chains along a axis.
THE CRYSTAL STRUCTURES OF IMIDAZOLE-[2-(2-HYDROXО-BENZYLIDENE)- N-(PROP-2-EN-1 YL)HYDRAZINCARBOTHIOAMIDE]-COPPER(II) AND (3,5- DIBROMOPYRIDINE)-[2-(2-HYDROXОBENZYLIDENE)-N-(PROP-2-EN-1- YL)HYDRAZINECARBOTHIOAMIDE]COPPER(II) NITRATES
(Academia de Ştiinţe a Moldovei, 2015) Petrenko, Peter A.; Graur, Vasilii О.; Chumakov, Yurii; Smaglii, Vadim; Tsapkov, Victor I.; Crudu, Valeriu; Eftodii, Sergiu; Gulea, Aurelian
CRYSTAL STRUCTURES OF NITRATO-COPPER(II) COMPLEXES COMPRISING 4,4’ -BIPYRIDYL AND SALICYLIDEN- OR NAPHTHALIDENAMINOETHANOL
(Academia de Ştiinţe a Moldovei, 2006) Chumakov, Yurii; Petrenko, Peter A.; Tsapkov, Victor I.; Bocelli, Gabriele; Gulea, Aurelian
Copper (II) nitrate with 2-[2-(hydroxyethylimino)-methyl]-phenol (H2L), 2-[2(hydroxyethylimino)-methyl]-naphtol (H2L1) and heterocyclic amines has been found to generate polynuclear coordination compounds with antimicrobial properties. It was established that polynuclear complexes are formed depending on the nature of the proton-accepting agent, pH and temperature of the reaction mixture. The structure of these compounds, dentate number of the nitrate group, physicochemical properties and antimicrobial activity are determined by the nature of these amines. It was of great interest to study how the replacement of different amines by 4,4’-bipyridyl (Bipy) affects the complex structure. In connection with this, we have synthesized complexes [Cu3(Bipy)3(H2O)2(HL)2(NO3)4]n (I) and [Cu2(Bipy)(HL1)2(NO3)2] (II), where L = 2-[(2-Hydroxy-ethylimino)methyl]-phenol, L1 = 1-[(2-Hydroxyethylimino)methyl]-naphthalen-2-ol, and determined their crystal structures by X-ray diffraction analysis. The crystal structure I consists of polymeric bands [Cu3(Bipy)3(H2O)2(HL)2(NO3)4] along [001] direction. The coordination polyhedra of Cu(1) and of Cu(2) are tetragonal bipyramids. The basic structural unit of II is the binuclear complex [(HL1)(NO3)Cu(Bipy)Cu(NO3)(HL1)] which forms the crystal structure II by means of multiple hydrogen bonds.
THE CRYSTAL STRUCTURES OF TWO IZOMERIC FORMS OF COPPER(II) CHLORIDE COMPLEXES OF 2-(2-(PHENYL(PYRIDIN-2- YL)METHYLENE)-HYDRAZINYL)BENZOTHIAZOLE
(Academia de Ştiinţe a Moldovei, 2012) Paholnitscaia, Anastasia; Chumakov, Yurii; Petrenko, Piotr; Gulea, Aurelian
INTRODUCING N-HETEROAROMATIC BASES INTO COPPER(II) THIOSEMICARBAZON COMPLEXES: A WAY TO CHANGE THEIR BIOLOGICAL ACTIVITY
(2022) Ulchina, Ianina; Tsapkov, Victor I.; Graur, Vasilii O.; Chumakov, Yurii; 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.
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
(John Wiley & Sons Ltd, 2020) Balan, Greta; Burduniuc, Olga; Usataia, Irina; Graur, Vasilii; Chumakov, Yurii; Petrenko, Peter; Gudumac, Valentin; Gulea, Aurelian; Pahontu, Elena
New zinc (II), copper (II), nickel (II) and cobalt (III) complexes, [Zn (HL) 2 ]I 2 (1), [Cu (HL)Cl 2 ](2), [Cu (HL)Br 2 ](3), [Cu (HL)(H 2 O) 2 ](ClO 4 ) 2 (4), [Ni (HL) 2 ]I 2 H 2 O(5), [Co(L) 2 ]Cl (6), [Co(L) 2 ]NO 3 (7), [Co(L) 2 ]I[Co(L) 2 ](I 3 ) (8) were obtained with 2-formylpyridine 4-allyl-S-methylisothiosemicarbazone (HL). The isothiosemicarbazone ligand was characterized by NMR ( 1 H and 13 C), IR spectroscopy and X-ray diffraction. All the complexes were character- ized by elemental analysis, IR, UV–Vis, ESI-MS spectroscopy, molar conductiv- ity, magnetic susceptibility measurements. X-ray diffraction analysis on the monocrystal and powder elucidated the structure of the complexes 1,5, 7and 8. The ligand and the complexes were tested for their antioxidant and antimi- crobial 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 5and cobalt complexes 6,7showed promising antiproliferative activity and low toxicity
SOME NEW Cu(II), Co(II) AND Ni(II) COMPLEXES CONTAINING AN ONS DONOR THIOSEMICARBAZONE: SYNTHESIS, CRYSTAL STRUCTURES AND BIOLOGICAL ACTIVITY.
(Academia de Ştiinţe a Moldovei, 2015) Pahontu, Elena Mihaela; Julea, Felicia; Chumakov, Yurii; Petrenko, Peter A.; Roşu, Tudor; Gulea, Aurelian
SYNTHESIS AND CRYSTAL STRUCTURE OF CHLORO-(2-FORMYLPYRIDINETHIOSEMICARBAZONO)COPPER DIMETHYL SULFOXIDE SOLVATE.
(Academia de Ştiinţe a Moldovei, 2015) Bairac, Natalia; Petrenko, Peter A.; Chumakov, Yurii; Gulea, Aurelian
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
(John Wiley and Sons, 2018) Pahontu, Elena; Usataia, Irina; Graur, Vasilii; Chumakov, Yurii; Petrenko, Valentin; 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.
SYNTHESIS, STRUCTURE AND ANTIMICROBIAL ACTIVITY OF SALICYLALDEHYDE 4-(DIMETHYLPHENYL) THIOSEMICARBAZONES AND BIOMETAL COORDINATION COMPOUNDS WITH THESE LIGANDS
(Academia de Ştiinţe a Moldovei, 2017) Gulea, Aurelian; Erhan, Tatiana; Zariciuc, Elena; Petrenko, Peter; Chumakov, Yurii; Jalba, Svetlana; Tsapkov, Victor