Browsing by Author "Gulea, Aurelian"

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Academician Gheorghe DUCA - The scientist who lives the present by learning from the past and investing in the future [Articol]
(2016) Gulea, Aurelian; Lupașcu, Tudor
Activatin of chemical agents by coordination and synthesis of new materials as biological active substances, catalysts, analytical reactives and molecular magnets [Articol]
(Academia de Ştiinţe a Moldovei, 2015) Gulea, Aurelian
Activitatea biologică a compușilor coordinativi ai Cu(II) și Bi(III) cu ioni aminopolicarboxilat și tiosemicarbazone ale 2-formil și 2-acetilpiridinei [Articol]
(CEP USM, 2022-11-10) Neguţa, Elena; Balan, Greta; Gulea, Aurelian; Bulimestru, Ion
Analiza comparativă a influenţei unor remedii ale zincului şi seleniului asupra anumitor indici morfologici ai ouălor de găină [Articol]
(2012-09-27) Țurcanu, Ștefan; Gulea, Aurelian; Bârcă, Maria; Ddidilică, Ina
Experiment were subjected laying hens of Hay-Sex cross. In study was taken two groups that received, according to the ration, zinc trichloroacetate tetrahydrate and zinc hidroselenite dihydrate. The results show a more positive evaluation of quantitative indices of the stock of eggs in presence of last one remedy.
Antibacterial, antifungal and in vitro antileukaemia activity of metal complexes with thiosemicarbazones [Articol]
(Wiley, 2015) Pahonțu, Elena; Julea, Felicia; Rosu, Tudor; Purcarea, Victor; Chumakov, Yurie; Petrenco, Petru; Gulea, Aurelian
1-phenyl-3-methyl-4-benzoyl-5-pyrazolone 4-ethyl-thiosemicarbazone (HL) and its copper(II), vanadium(V) and nickel(II) complexes: [Cu(L)(Cl)]·C2H5OH·(1), [Cu(L)2]·H2O (2), [Cu(L)(Br)]·H2O·CH3OH (3), [Cu(L)(NO3)]·2C2H5OH (4), [VO2(L)]·2H2O (5), [Ni(L)2]·H2O (6), were synthesized and characterized. The ligand has been characterized by elemental analyses, IR, 1H NMR and 13C NMR spectroscopy. The tridentate nature of the ligand is evident from the IR spectra. The copper(II), vanadium(V) and nickel(II) complexes have been characterized by different physico-chemical techniques such as molar conductivity, magnetic susceptibility measurements and electronic, infrared and electron paramagnetic resonance spectral studies. The structures of the ligand and its copper(II) (2, 4), and vanadium(V) (5) complexes have been determined by single-crystal X-ray diffraction. The composition of the coordination polyhedron of the central atom in 2, 4 and 5 is different. The tetrahedral coordination geometry of Cu was found in complex 2 while in complex 4, it is square planar, in complex 5 the coordination polyhedron of the central ion is distorted square pyramid. The in vitro antibacterial activity of the complexes against Escherichia coli, Salmonella abony, Staphylococcus aureus, Bacillus cereus and the antifungal activity against Candida albicans strains was higher for the metal complexes than for free ligand. The effect of the free ligand and its metal complexes on the proliferation of HL-60 cells was tested.
Antimicrobial and antifungal activity of Cu(II) and Bi(III) complexes based on aminopolycarboxylate ions and 2-formyl and 2-acetylpyridine thiosemicarbazones [Articol]
(2021) Neguța, Elena; Balan, Greta; Gulea, Aurelian; Bulimestru, Ion
The biological properties of thiosemicarbazones are often related to metal coordination, which as result affects lipophilicity that controls the rate of entry into the cell. Metal complexes are generally more active than the free ligand, or the metal complex can be a vehicle for activation of the ligand as the cytotoxic agent. Among biologically ac- tive metal compounds, copper (II) complexes with 2-formyl and 2-acetylpyridine thio- semicarbazones proved to be among the most potent antiviral, antitumor and anti-inflam- matory agents. Bismuth compounds have been widely used in medicine for more than two centuries due to their high effectiveness and low toxicity. In the antimicrobial realm, ap- plications have been widespread, due to bismuth antiseptic, astringent, protective, ant- acid, antisecretory and local gastrointestinal properties.
The Antiproliferative, Antioxidant Activities and Toxicity of Mixed-Ligand Amine-Containing Copper (II) Coordination Compounds with 2-(2-Hydroxybenzylidene)-N-(Prop-2-En-1-Yl) Hydrazinecarbothioamide [Articol]
(2021-09-16) Garbuz, Olga; Toderaș, Ion; Ulchina, Ianina; Graur, Vasile; Railean, Nadejda; Gulea, Aurelian
Five compounds 2-(2-Hydroxybenzylidene)-N-(prop-2-en1-yl)hydrazinecarbothioamide (H2L), bis[μ2-2-({2-[(prop-2-en-1-yl) carbamothioyl] hydrazinylidene}methyl) phenolatoS,N,O:O] diaquadicopper (II) nitrate (1), bis [μ2-2-({2-[(prop-2-en-1-yl) carbamothioyl] hydrazinylidene}methyl)phenolato-S,N,O:O]d iimidazoldicopper(II) nitrate (2), bis[μ2-2-({2-[(prop-2en-1-yl)carbamothioyl]-hydrazinylidene}methyl)phenolato-S,N,O:O]bis-(3,5-dibromopyridine)dicopper( II) nitrate hexahydrate (3), bis[μ2-2-({2-[(prop-2-en-1-yl)carbamothioyl]-hydrazinylidene}methyl) phenolato-S,N,O:O]bis(4-methylpyridine)dicopper(II) nitrate hexahydrate (4) were synthesized. The antiproliferative properties of these compounds towards cancer cell lines HeLa, RD and normal cell line MDCK have been investigated. The tested compounds demonstrated high antioxidant and antiproliferative, selective activities towards cancer cells. Direct toxic evaluation of compounds was performed by Daphnia magna bioassay.
Aromatic isothiocyanatopropenones and thiourea derivatives. Synthesis and biological properties [Articol]
(2014) Barba, Nicanor; Gulea, Aurelian; Popușoi, Ana; Lozan-Tîrșu, Carolina; Poirier, Donald
În prezenta lucrare se descriu metode de sinteză a unor propenone aromatice cu grupe tioamidice sau izotiocian şi caracteristica lor biologică in vitro. Prin condensarea în cataliză acidă sau bazică a 4-(dimetilamino)benzaldehidei 4-Hidroxi-3-metoxibenzaldehidei şi furan-2-carbaldehidei cu 3-(4-acetilfenil)-1,1dimetiltioureea au fost obţinute propenone aromatice cu grupări –NHCSN(CH3)2, care la tratare termică sau în prezenţă de agenţi cu caracter acid (HCl, H2SO4, (CH3CO)2O, CH3COCl) elimină dimetilamină, transformîndu-se în izotiocianato -propenon cu randamentul de 54-92 %. La tratarea izotiocianatopropenonelor cu amine primare au fost obţinuti derivaţi cu grupări tioamidice-NHCSNH. Structura compuşilor noi obţinuţi cu conţinut de sulf a fost confirmată prin analiză elementală şi spectrală IR, 1H-, 13C- RMN. Compuşii sintetizaţi au fost testaţi ca inhibitori ai proliferării celulelor leucemice (HL-60), iar pentru produşii care au manifestat proprietăţi mai ponunţate, a fost testată in vitro activitatea lor antibacteriană faţă de unele microorganisme gram-pozitive şi gram-negative: Escherichia coli, Staphylococcus aureus, Shigella sonnei, Salmonella abony şi Bacillus cereus.
Bioassay and estimation of the toxicity of metalorganic compounds impacting the population of paramecium caudatum [Articol]
(Academia de Ştiinţe a Moldovei, 2017) Toderash, Ion; Gulea, Aurelian; Roscov-Arcan, Elena; Garbuz, Olga
Biotestarea şi estimarea toxicităţii compuşilor metalooragnici asupra populaţiei de Paramecium caudatum [Articol]
(CEP USM, 2016) Toderaș, Ion; Gulea, Aurelian; Roșcov, Elena; Garbuz, Olga
În articol este studiată influenţa unor grupuri de substane metaloorganice asupra microorganismelor acvatice. Este utilizată metoda de biotestare toxicologică a compuşilor coordinativi CMT-28 şi CMA-18 asupra ciliatelor Paramecium caudatum Ehrnbg,în concentraţii de 100, 10, 1, 0,1, 0,01 uM/L, comparativ cu prototipul. Metoda de biotestare ne permite să formulăm rapid concluzii în plan comparat, evitând riscul unei erori înalte.Proprietăţile compuşilor metaloorganici au fost cercetate prin metoda diluărilor în serie, în mediul nutritiv lichid (1 g soluţie nutritivă/1 l apă). În calitate de culturi de referinţăau fost folosite ciliatele Paramecium caudatm. Infuzoriile, ca obiecte de cercetare, sunt foarte comode, se reproduc destul de rapid, fiind cele mai convenabile test-obiecte pentru investigaţii în condiţii de laborator, în care factorul timp joacăun rol decesiv, inclusiv pentru elucidarea impactului unor factori abiotici (substanţelor metaloorganice) asupra procesului de reproducere asexuatăla Paramecium caudatum. Activitatea substanţelor a fost evaluată după caracterul toxicităţii preparatelor (LT50 şi LC50), iar activitatea ciliatelor a fost studiată după caracterul viabilităţii şi parametrii reproductivi (creşterea sau diminuarea efectivului numeric şi a ratei lor de reproducere). Toxicitatea acută(LT50 şi LC50) a compuşilor a fost cercetată conform recomandărilor metodice privind studierea toxicităţii generale a remediilor farmaceutice. LC50(concentraţia letală, 50%) – concentraţia care cauzează moartea a 50% din test-organisme într-o anumită perioadă de timp. LT50(timpul letal, 50%) – timpul în care concentraţia utilizată a compusului testat cauzează moartea a 50% din organismele testate.
Cobalt, nickel, and copper coordination compounds with 3-phenylpropenal benzoylhydrazone [Articol]
(2006) Samusi, Nina; Gulea, Aurelian; Țapcov, Victor
3-Phenylpropenal benzoylhydrazone (HL) reacts with cobalt, nickel, and copper chlorides, nitrates, and acetates to give coordination compounds MX 2 • nH2O [M = Co, Ni, Cu; X = Cl, NO3, HL = C6H5CH=CHCH=NNHC(O)C6H5; n = 0, 2] and ML2 • nH2O (M = Co, Ni, Cu; n = 1-3). Complexes MALCI (M = Co, Ni, Cu) were obtained by these reactions in the presence of amines (A = C5H5N, 2-CH3C5H 4N, 3-CH3C5H4N, 4-CH 3C5H4N). All the compounds have a monomeric structure. Azomethine (HL) in them behaves as a bidentate N,O-ligand. Thermolysis of the complexes involves the stages of dehydration (70-90°C), deaquation (145-155°C) or deamination (145-185°C), and complete thermal decomposition (330-490°C).
COMBINAȚII COORDINATIVE ALE Cu(II) ÎN BAZA N-HEXIL-2-[(PIRIDIN-2-IL)METILIDEN]HIDRAZINE-1-CARBOTIOAMIDEI: PROIECTARE, SINTEZĂ, EVALUAREA PROPRIETĂȚILOR ANTIMICROBIENE ȘI ANTIFUNGICE
(CEP USM, 2024) Pîntea, Aliona; Ciursin, Andrei; Rusnac, Roman; Gulea, Aurelian
Dezvoltarea rezistenței la antibiotice, noile pandemii și creșterea cazurilor de cancer sunt unele din provocările principale pentru societatea modernă. Rezolvarea acestor probleme este direct legată cu sinteza substanțelor noi cu efectele biologice pertinente. O perspectivă majoră prezintă clasa de substanțe numită tiosemicarbazone, reprezentanții cărora deja sunt utilizați în industria farmaceutică, spre exemplu, Ambazona sau Triapina. În general, tiosemicarbazonele manifestă un șir larg de activități biologice utile, printre care sunt antibacteriene, antifungice și anticancer. Este cunoscut că coordinarea tiosemicarbazonelor în majoritatea cazurilor duce la îmbunătățirea activității biologice. În această lucrare au fost sintetizați 5 compuși coordinativi noi ai cuprului(II) în baza unei tiosemicarbazone HL, cu denumirea IUPAC - N-hexil-2-[(piridin-2-il)metiliden]hidrazine-1-carbotioamida. La substanțele sintetizate au fost evaluate proprietățile antimicrobiene și antifungice.
Combinații coordinative ale Cuprului(II) Cu ({(2 [(piridin-2-il)metiliden]hidrazincarbotioil} amino) acetat de etil cu proprietăți antioxidative [Articol]
(CEP USM, 2024) Bîrcă, Maria; Rusnac, Anna; Garbuz, Olga; Evtodienco, Carolina; Gulea, Aurelian
In this work, ethyl 2-isothiocyanatoacetate and [(hydrazinecarbotyoyl)amino]ethyl acetate, which are precursors of thiosemicarbazones, were synthesized.Based on these compounds, the synthesis of two new thiosemicarbazones ethyl 2-(2-(pyridin-2-ylmethylene)hydrazinecarbothioamido)acetate (Hl1) and ethyl 2-(2-(1-(pyridin-2-yl)-ethylidene)hydrazinecarbothioamide)acetate (Hl2) with yields between 85-88%. The thiosemicarbazones obtained were confrmed using 1H and 13C-nMR and FTIR spectroscopy. For the frst time, 8 coordination compounds were obtained based on thiosemicarbazone (Hl1 - Hl2) and Cu(II) salts: [Cu(l1)Br], [Cu(l1)(H2O)Cl], [Cu(l1)nO3], [Cu(l1)(H2O)ClO4], [Cu(l2)Br], [Cu(l2)(H2O)Cl], [Cu(l2)nO3], [Cu(l2)(H2O) ClO 4]. The composition of the synthesized coordination compounds was determined by elemental metal analysis and IR spectroscopy.For the synthesized compounds, the antioxidant capacity was evaluated by means of the aBTs method. In which ethyl 2-(2-(pyridin-2-ylmethylene)hydrazinecarbothioamido)acetate (Hl1) and ethyl 2-(2-(1-(pyridin-2-yl)ethylidene)hydrazinecarbothioamido)acetate (Hl2) were shown to exhibit the best results compared to the reference substance Trolox.
Complecși Ln(III)-Bi(III) în baza ionilor trietilentetraaminhexaacetat -precursori moleculari pentru oxizii micști BiLnO3 [Articol]
(CEP USM, 2020) Popa, Nelea; Bulimestru, Ion; Gulea, Aurelian
Lucrarea este axată pe sinteza și studiul unui șir de combinații coordinative heterometalice ale lantanidelor(III) și bismutului(III) cu formula generală LnBi(ttha)·nH2O (ttha6-=trietilentetraaminhexaacetat) pe rol de precursori moleculari pentru obținerea oxizilor micști BiLnO3. În baza spectrelor IR a fost stabilită prezența a două serii de complecși analogi (Ln(III)= La, Pr, Nd, Gd, Dy, unde n=7 și Ln(III) = Ho, Er, unde n=10). Analiza termogravimetrică efectuată în flux de oxigen generează oxidul preconizat BiLnO3 deja la 600 o C, pe când în flux de azot acest proces nu este finalizat nici la 900oC. Difracția razelor X pe pulberile obținute la descompunerea termică a precursorilor a confirmat că viteza de calcinare și natura ionilor Ln(III) nu influențează compoziția reziduurilor finale, în toate cazurile obținându-se oxizii heterometalici preconizați BiLnO3 în stare pură.
Complexes of 3dn Metal Ions with Thiosemicarbazones: Synthesis and Antimicrobial Activity [Articol]
(MDPI AG, 2007) Rosu, Tudor; Gulea, Aurelian; Nicolae, Anca; Georgescu, Rodica
The chelating behavior of the thiosemicarbazone derivatives of 2-hydroxy-8-R-tricyclo[7.3.1.0.2,7]tridecane-13-one (where R = H, CH3, C6H5) towards Co(II), Ni(II) and Cu(II) has been investigated by elemental analysis, molar conductivity measurements, UV-VIS, IR, ESR spectroscopy and thermal studies. It was deduced from the experiments performed that the ligands coordinate to metal ions in different ways – neutral bidentate or mononegative bidentate – depending on the nature of R. Also, if metal acetates are used instead of metal chlorides, the ligands coordinate in a mononegative bidentate fashion, regardless of the nature of R or the thiosemicarbazone type ligand. The antimicrobial activity of the ligands and of the complexes towards samples of Acinetobacter boumanii, Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa was determined.
Compounds removed from the condensation reaction between 2-acetylpyridine and 2-formylpyridine [Articol]
(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.
Compuși coordinativi ai fierului(III) cu unele tiosemicarbazone N(4) – substituite ale derivaților salicil aldehidei și cinam aldehidei [Articol]
(CEP USM, 2024) Bîrcă, Maria; Rusnac, Roman; Gulea, Aurelian
In this paper, the purpose of synthesis of Fe(III) coordination compounds with some N(4)-substituted thiosemicarbazones of salicyl aldehyde and cinnam aldehyde derivatives was pursued: which contain as a radical in the N(4) position: tert-butyl, cyclohexyl; allyl, methyl. The structure of thiosemicarbazones HnL1-5 was confirmed by FTIR spectroscopy and TLC analysis, melting point and NMR spectra. Based on the above-mentioned ligands, 5 coordination combinations were obtained, the research of which was carried out with the help of infrared spectroscopy. All synthesized compounds are being researched for their biological properties: antimicrobial and antifungal, as well as antioxidant capacities.
Compușii coordinativi ai Cu(II), Ni(II) și Co(III) 3D cu tiosemicarbazidele substituite [Articol]
(CEP USM, 2022-11-10) Bîrcă, Maria; Ţapcov, Victor; Garbuz, Olga; Borta, Ioana; Gulea, Aurelian
Coordination chemistry in the Republic of Moldova [Articol]
(Institute of Chemistry of ASM, 2009) Bulhac, Ion; Gulea, Aurelian; Batâr, Dumitru
This articleis dedicated to the history of apparition and development of Coordination chemistry in Moldova. The main scientifi c centres are characterized, as well as their main research directions. The most valuable results in fundamental and applicative research are described, obtained in the fi eld of coordination chemistry in the republic.
Coordination chemistry in the Republic of Moldova [Articol]
(2009) Bulhac, Ion; Gulea, Aurelian; Batâr, Dumitru
This article is dedicated to the history of apparition and development of Coordination chemistry in Moldova. The main scientiﬁc centres are characterized, as well as their main research directions. The most valuable results in fundamental and applicative research are described, obtained in the ﬁeld of coordination chemistry in the republic.