Four new derivatives of 2-pyridine mono(thio)carbohydrazones were synthesized by condensation of carbaldehydes with carbohydrazide and thiocarbohydrazide following a known procedure. Compounds obtained were characterized using FT-IR, NMR, and UV-Vis spectroscopy, and their purity was determined by elemental analysis. Within the investigation of biological activity, four derivatives were subjected to antioxidative and antimicrobial studies, showing significant results. All obtained results concerning biological activity were supported by TD-DFT calculations. Comparing, monothiocarbohydrazones have shown much better activity than monocarbohydrazones. As a part of the characterization of potentially biologically active compounds ionization constants of synthesized compounds were theoretically predicted, experimentally determined and their mutual similarities i.e. differences were confirmed with NBO analysis.

Monitoring of surface water, through the analysis of physical-chemical and chemical parameters is a very important factor in the control of water quality and the health of living beings. Surface water quality is largely determined by the nature (atmospherics) and anthropogenic processes (discharge of municipal and industrial waste water). The results of monitoring of surface water are usually too expensive and difficult for correct interpreting, due to the spatial and temporal variations in water quality. By applying Multivariate statistical analysis can achieve significant reductions of the ampleness of the available data and the better interpretation of the obtained results about the quality and ecological status/potential of water. In this paper, were analyzed selected results of the analysis of surface water in AP Vojvodina in 2011 year by using multivariate statistical analysis (cluster analysis and principal components analysis). These techniques allow the interpretation of the results of the monitoring program of investigated surface water bodies and simultaneous identification of registered influence and potential sources of pollution on the quality of the given water bodies. With both methods applied and the division of water bodies tested in the same manner at the origin (natural and artificial) and on the basis of territorial belonging monitoring stations (Banat and Backa). Individual variations are discussed in corresponding differences in individual measuring stations in relation to others. Application of the given method, a grouping of the examined indicators of water quality in the following factors: hydro-chemical factor, ecological factor, the factor point pollution and diffusion. The obtained results confirm the initial hypothesis that the use of different statistical methods can identify the main factors that have an impact on the ecological status and ecological potential of water bodies and to improve the existing monitoring. In addition, analysis of the extracted surface water bodies where it is necessary to implement simultaneous monitoring of the biological quality elements to determine whether chemical parameters ensure the functioning of ecosystems.

Barbituric acid derivatives have been pharmacologically significant compounds for decades. The central nervous system effects are conditioned by the presence of the pyrimidine-trione ring and the nature of the substituent in position 5. Lipophilicity as one of the key molecular descriptors of biological activity for selected barbituric acid derivatives was determined experimentally, using reversed-phase thin layer chromatography (RP TLC18 F254s), in two solvent systems. The influence of the substituent’s nature and the effects of applied organic modifiers on the chromatographic behavior of the tested derivatives were examined. For the studied derivatives the values of the partition coefficient (logP) as a standard measure of lipophilicity and effective concentration (EC50) as a measure of acute toxicity for different test organisms were calculated applying the appropriate software packages. Dependence between the chromatographic parameters as assumed measures of lipophilicity and the software-derived biological activity parameters of the studied barbituric acid derivatives were studied by linear regression analysis. Keywords: barbituric acid derivatives, lipophilicity, toxicity.