Using on-line services and the ChemBioOffice2014 software package the values of the partition coefficients of some N-R-amine derivatives have been calculated. To identify the quantitative relationships and select the optimal algorithm of calculations the correlation and regression analysis of the values obtained has been conducted. Statistically significant values of correlation for the partition coefficients calculated have been determined. It has been shown that it is advisable to use the value AlogPs for further application.Lipophilicity is one of the criteria for assessing the similarity of synthetic substances and drugs, and it affects the biological activity of substances [9,13,14]. The partition coefficient of n-octanol-water (logP) characterizes physicochemical properties of substances in solutions and is used to simulate their behaviour in the body [3,14]. Distribution and redistribution of substances between lipophilic (fatty) and aqueous phases are part of biological processes, in particular transmembrane transport through lipid layers [11]. Hydrophobicity plays an important role in determining distribution of a substance in the body after absorption, its metabolic rate and elimination. The hydrophobic effect is essential for binding of drugs with their receptors [13].The ability to predict biological properties of compounds through their lipophilicity allows to optimize the search for new drugs and is often included in equations for calculations of the quantitative structure -activity relationships (QSAR) [16].The value logP is experimentally determined by the classical method of measuring distribution of organic compounds between the non-polar phase and water [14] using chromatographic [18], electrochemical [23] and other methods.However, experimental methods to determine logP are time-consuming and expensive, and the values obtained often differ due to the influence of many factors. Therefore, today a significant number of algorithms for theoretical calculations of values logP implemented using the appropriate software [5, 6, 8, 17,24, 25].The values of the partition coefficients of n-octanolwater experimentally obtained with the values theoretically calculated by different algorithms (AlogPs, IAlogP, ClogP, miLogP, logP KowWIN , xlogP3, etc.) were compared for 193 substances [19] and more than 96 000 compounds (including databases of Nykomed and Pfizer) [15]. In both studies the experimental data better correlate with the methods of AlogPs, xlogP3, logP KowWIN .Attempts to achieve proportionality of results of the theoretical calculation methods of prediction and the experimental determination of lipophilicity of organic compounds are still relevant in modern scientific studies [1, 16, 22].The aim of this work is to determine the mutual correlation of the values of the partition coefficients in the series of some functional derivatives of N-R-amines (1-21) calculated by different algorithms. Materials and MethodsTaking into account the data [15,19] we used the available free on-line methods xlog...

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The presence of the antibacterial and antifungal activity in derivatives of amino acids is determined by different mechanisms; therefore, a promising field of research is to obtain new N-substituted amino acids and study their antibacterial action.Aim. To determine the quantitative "structure -antibacterial action" relationships in a series of N-substituted amino acids. Materials and methods. The quantitative dependencies of the antibacterial action of the compounds studied on AlogPs values were calculated using the STATISTIKA 8 program.Results and discussion. The satisfactory values of the levels of correlation of AlogPs parameters calculated with the experimental data of the antibacterial activity of N-substituted amino acids against S. aureus, E. coli, P. vulgaris, P. aeruginosa, B. subtilis, and Cl. perfringens are statistically significant. The absence of the relationship between the antibacterial effect against C. albicans and the structure of threonine derivatives may indicate a possible role of the latter in the metabolism of these fungi.Conclusions. The statistically significant correlation values of AlogPs with the values of the antibacterial action of N-substituted amino acids against the microorganisms studied have been determined, and it quantitatively confirms the earlier assumptions of the existence of the "structure -action" relationship in this series of compounds and the degree of its manifestation.