Chemistry Journal of Moldova. General, Industrial and Ecological Chemistry

6-9

Authors: T. L. Kalabegishvili, I. Murusidze, D. T. Pataraya, E. Ginturi, M. V. Frontasyeva, E. I. Kirkesali, Gh. Duca, I. Zinicovscaia

The increasing contamination of soil, sediment, and water with heavy metals by natural and industrial processes is a worldwide problem. Many bacteria and microalgae have demonstrated ability to absorb toxic elements. To study mercury biosorption by bacteria Arthrobacter globiformis and microalga Spirulina platensis neutron activation analysis (NAA) was applied. The process of mercury biosorption by these media was described by Freundlich and Langmuir-Freundlich Model. Both microorganisms showed a great potential to be used as biosorbing agents for mercury removal from the environment.

29-44

Authors: N. Secara, Gh. Duca, L. Vlad, F. Macaev

The paper summarizes literature data on occurrence of dihydroxyfumaric acid and its role in biological systems, as well as its chemical properties.

52-56

Authors: Ludmila Chiriac, Tatiana Cazac, I. Povar and M. Revenco

The polarographic catalytic current in acid solutions of Mo(VI), 2,3-dihydroxybenzaldehyde thiosemicarbazone (TSC 2,3-DHBA) and chlorate ions has been investigated. The scheme of reactions, taking place in the solutions and on the electrode, has been proposed. The increase of the catalytic current is explained by the formation of an active intermediate complex [Mo(V)⋅TSC 2,3-DHBA (ClO- 3)]. The rate constant of this complex formation K = 2.56 ⋅ 106 mol-1⋅dm3⋅s-1, the activation energy Ea = 15.9 kcal⋅mol-1 and the reaction activation entropy ΔSa ≠ = -23.5 e.u. have been calculated.

62-68

Authors: Gheorghe Nemţoi, Tudor Lupaşcu, Alexandra Ciomaga, Alexandru Cecal

This paper presents the results of scientifi c research related to the electrochemical behavior of the complex preparation, Enoxil. It was established that the oxidation-reduction process of Enoxil is quasireversible. The reactivity of Enoxil obtained from alcohol soluble enotannins is more pronounced, compared to that obtained from standard enotannins. The dependence of cathodic current intensity on Enoxil concentration is linear. This can be used to establish Enoxil concentration in solution. Cyclic voltammograms were used to establish reduction and oxidation potential and the formal redox potential on platinum electrode in sodium perchlorate aqueous environment. These features can be used for identifi cation and determination of Enoxil in pharmaceuticals.

73-76

Authors: Valerian Cerempei

The article investigates phase stability for the mixtures of monoatomic alcohols (ethanol, butanol) with gasoline in the presence of water. There have been determined the optimal storage conditions of mixtures depending on their composition and mixing conditions. The positive infl uence of butanol on the phase stability of ethanolgasoline mixtures was detected.

81-85

Authors: Elena Nezalzova

Quality control of alcoholic beverages, coming into the market, is a defi ning element in preventing the production and supplying of defective products. One of the main criteria for quality control of wine distillates is to estimate their age, and more precisely the period of maturation as the dominant factor in determining the quality of cognacs and, consequently, their market price. On the opinion of majority scientists, one of the main factors, which determines the age of wine distillates, is the content of aromatic aldehydes, mostly vanillin, and their ratio.

101-109

Authors: Oleg Radul, Natalia Sucman, Serghei Pogrebnoi, Alic Barba, Athina Geronikaki, Fliur Macaev

The synthesis and antiviral activity evaluation of new derivatives of 2-aminothiazole, 1,2,4-triazole, as well as oxindoles has been realized. The synthesized compounds exhibited different cytotoxicity, in particular, oxindols 4 , 5 , 7 , 8 , 9, 10, 11, 12, 13, 58 as well as thiazole/triazole 73 and 75 turned out to be the most cytotoxic for MT-4 cell lines. The compounds 11, 12, 73, and 75 are more toxic than reference compound Efavirenz. As far as the antiviral activity is concerned, none of the title compounds turned out active against Reo-1, Sb-1, VSV, RSV, YFV and VV viruses. The results obtained against Bovine Viral Diarrhoea Virus (BVDV) showed that nine compounds (six from oxindol’s seria 6, 12, 13, 52, 56, 58 and three 73, 75, 77 of triazole homologues) resulted moderate active. Among all of them, the most potent compound was 52, with EC50 of 6.6 μM. Studies of effect of synthesized compounds against Coxsakie Virus (CVB-2) revealed that only two compounds, 13 and 73 exhibit moderate activity (EC50 >40 and >18 μM, respectively). It should be noticed that eleven compounds, 4, 5, 7, 8, 9, 10, 11, 12, 13, 58, and 75 showed moderate activity against HIV-1 (EC50 >16 – m >59μM).