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

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Start date: 2019End date: 2019

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    Геотубная технология очистки сточных вод и проблемы дезодорирования биогазовых выбросов
    (2019) Ковалёв, Виктор; Ковалёва, Ольга
    Utilizând ca exemplu funcţionarea staţiilor de epurare, autorul supune analizei cauzele emanaţiilor rău mirositoare dintr-un oraș cu statut de capitală, care au caracter tehnogen. S-a demonstrat că cea mai probabilă cauză a mirosurilor de acest fel este formarea compușilor organici, cu miros neplăcut, din clasa mercaptanilor (sau tioli – conform noii clasifi cări) care conţin sulf. Aceste substanţe sunt eliberate în biogaz din geotuburi ca urmare a digestiei anaerobe a biomasei. Procesul este asociat cu interacţiunea dintre produsele rezultate în urma transformărilor compușilor organici descompuși biochimic și hidrogenul sulfurat, care este întotdeauna conţinut în biogaz. Aceste procese sunt iniţiate în volumul geotuburilor, care au rolul reactoarelor de biogaz din staţiile de epurare, datorită încălzirii solare a biomasei. În acest caz, se obţin condiţiile de fermentare mezofi lă, care sunt optime pentru această reacţie (până la 30 ± 3 °C sau mai mult). Răspândirea emanaţiei rău mirositoare este facilitată de structura poroasă a materialului geotuburilor, suprafaţa fi ecăruia dintre acestea fi ind de aproximativ 3000 m2, iar numărul lor total fi ind de câteva zeci. Efectul emanaţiilor de acest fel este de natură ciclică, care se manifestă anual în ultimii ani, deoarece intensitatea lor coincide cu creșterea temperaturilor medii de vară. Prin urmare, emanaţiile în cauză pot fi atribuite și manifestării încălzirii globale. În acest sens, pentru a preveni repetarea unui asemenea proces, care se poate dezvolta și mai mult, este necesar să fie supuse analizei și să fie studiate caracteristicile acestuia.
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    ПОВЫШЕНИИЕ ЭНЕРГЕТИЧЕСКИХ ХАРАКТЕРИСТИК БИОГАЗА: ЧАСТЬ 1.ТЕХНОЛОГИЧЕСКИЕ ФАКТОРЫ, ВЛИЯЮЩИХ НА ПРОЦЕСС МЕТАНОГЕНЕЗА
    (2019) Ковалёв, Виктор; Ковалёва, Ольга; Ненно, Владимир
    Energetica bazată pe biogaz, dezvoltată în lume, şi în special în Republica Moldova, este una dintre componentele importante şi de perspectivă ale dezvoltării economiei şi asigurării securităţii ecologice în societate. În materialul dat este prezentată analiza ştiinţifi copractică a problemelor în acest domeniu şi căile de rezolvare a acestora. A fost elaborat conceptul, sunt descrise elaborările noi care vizează atingerea acestor obiective, inclusiv caloricitatea înaltă a biogazului la nivelul de gaz natural.
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    REGIONAL CLIMATE CHANGE AND SURFACE WATERS
    (2019) Duca, Gheorghe; Nedealcov, Maria; Travin, Serghei; Gladchi, Viorica
    The actual period marred by the global warming requires expanding our knowledge on the regional particularities of climate changes manifestations as consequences of global climatic changes. It was stated that within the limits of Republic of Moldova’s territory the pace of warming is much more accelerated than the global one. These consequences, in their turn, had led to the increase in degree of evaporation of surface waters, which had conditioned the doubling of still water’s pollution in the region (Lake Beleu). We consider that the obtained results could contribute to the adequate management of water resources in the new climatic conditions.
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    SELF-PURIFICATION OF AQUATIC MEDIA FROM HEXACHLOROCYCLOHEXANE IN A RADICAL PROCESS
    (2019) Travin, Serghei; Duca, Gheorghe; Gladchi, Viorica
    It is known, that highly toxic pesticide hexachlorocyclohexane (HCH) is resistant to decomposition and has a long-term accumulating capacity. Nevertheless, it undergoes complete degradation in reactions with hydroxyl radicals in Fenton-like systems. The goal of this work was to study the influence of HCH on the processes of radical self-purification of water bodies and to explain the mechanisms of chemical transformation of substances occurring in natural waters, as well as to reveal the kinetic characteristics of the processes of radical self-purification of water bodies. It was found, that HCH plays a dual role for aquatic ecosystems – it is not only a scavenger of free radicals, but also an additional initiator. Under the influence of light in the surface layer of water, HCH generates radicals, thus contributing to the self-purification processes.
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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
    (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, CHARACTERIZATION, MOLECULAR DOCKING STUDIES AND IN VITRO SCREENING OF NEW METAL COMPLEXES WITH SCHIFF BASE AS ANTIMICROBIAL AND ANTIPROLIFERATIVE AGENTS
    (2019) Paponțu, Elena; Proks, Maria; Șova, Sergiu; Lupașcu, Gina; Ilieș, Diana Carolina; Bărbuceanu, Ștefania Felicia; Socea, Laura Ileana; Badea, Mihaela; Păunescu, Virgil; Istrati, Dorin; Gulea, Aurelian; Drăgănescu, Doina; Dinu Pîrvu, Cristina Elena
    A series of Cu(II), Co(II), Pd(II), Pt(II), Zn(II), Cd(II) and Fe(III) complexes were designed and synthesized using Schiff base 1-phenyl-2,3-dimethyl-4-(N-3-formyl-6-methylchromone)-3-pyrazolin-5-one (HL). The new metal complexes were investigated using various physicochemical techniques including elemental and thermal analyses, molar electric conductivity and magnetic susceptibility measurements, as well as spectroscopic methods. Also, the crystal structures of ligand HL and the Pd(II) complex were determined using single-crystal X-ray diffraction analysis. For all compounds, the antimicrobial activity was studied against a series of standard strains: Staphylococcus aureus, Bacillus cereus, Enterococcus faecalis, Escherichia coli, Acinetobacter baumannii, Candida albicans, Candida krusei and Cryptococcus neoformans. The in vitro antiproliferative activity of the ligand and complexes was evaluated against ten cancer cell lines: MSC, A375, B16 4A5, HT-29, MCF-7, HEp-2, BxPC-3, RD, MDCK and L20B. At 10 μM concentration a significant cytotoxic effect of the Co(II), Pd(II) and Cd(II) complexes was observed against B16 4A5 murine melanoma cells. The Zn(II) complex is active against HEp-2, RD and MDCK cancer cell lines, where IC50 values vary between 1.0 and 77.6 and for BxPC-3 the activity index versus doxorubicin is 3.7 times higher.
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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)HYDRAZINE- CARBOTHIOAMIDES
    (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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    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
    (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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    COORDINATION COMPOUND AS INHIBITOR OF SUPEROXID RADICAL
    (2019) Garbuz, Olga; Pantea, Valeria; Usataia, Irina; Graur, Vasilii; Țapcov, Victor; Sardari, Veronica; Tagadiuc, Olga; Gudumac, Valentin; Gulea, Aurelian
    A fost obținut un nou compus coordinativ biologic activ, nitratul de cupru [2 - ({2 [(ethylsulfanyl) (prop-2-en-1-yl) carbononoimidooyl] -hydrazinylidene} methyl) phenolate], care face parte din clasa isotiosemicarbazidelor metalelor de tranziție.S-a stabilit că acesta exercită proprietăți anti radicalice performante la acțiunea moleculei organice cu radicalul superoxidic. Datorită acestei poroprietăți compusul obținut poate avea o potențială aplicare in medicină in calitate de inhibitor al radicalilor superoxidici in corpul uman, care poate duce la prevenirea deteriorării tesutului cellular, aterosclerozii si carcinogenezei.Compusul coordinativ sintetizat extinde arsenalul inhibitorilor de radicali superoxidici cu activitate biologică importanta.
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    PROCEDEU INOVATIV DE SPORIRE A CONŢINUTULUI DE POLIZAHARIDE ACIDE LA CIANOBACTERIA SPIRULINA PLATENSIS
    (2019) Zosim, Liliana; Bulimaga, Valentina; Rudic, Valeriu; Gulea, Aurelian; Țapcov, Victor
    A fost elaborat un procedeu inovativ de sporire a conţinutului de polizaharide acide la cianobacteria Spirulina platensis, cultivată în prezenţa compusului coordinativ (PPh4)2[Mo2O2S2(IDA)2].2,8H2O. A fost propusă schema integrală de realizare a procedeului de cultivare a spirulinei şi de obţinere a polizaharidelor din biomasă.