Biological activity of a molecule is closely related to its lipophilicity. This significant parameter was determined for a group of potentially bioactive N-(4-phenylmonosubstituted)-2-cyanoacetamides applying thin-layer chromatography on reversed phase (RP-TLC) in mixtures of water and two organic modifiers separately, i-propanol and dioxane. The effect of the chemical structure of derivatives and the influence of the applied organic modifier on their retention were studied. The determined chromatographic retention constants, R_M⁰, and the chromatographic parameter, m, of compounds were correlated with software calculated partition coefficients, log P as the standard measure of lipophilicity and with different pharmacokinetic predictors applying classical linear and multiple regression analysis. By classical linear regression analysis in both water-modifier systems only R_M⁰-log P and m-log P correlations were established (average r, 0.909 and 0.826). All studied relationships were enhanced by molecular descriptors that fulfilled the modified Lipinski's rule of five. Thereby, the performed multiple regression analysis gave better correlations (for R_M⁰-log P and m-log P average r², 0.994 and 0.993; for R_M⁰-pharmacokinetic parameters and m-pharmacokinetic parameters average r² 0.978 and 0.980). The obtained results indicate that the chromatographic parameters, R_M⁰ and m determined by RP-TLC at given conditions could be used successfully for the description of lipophilicity and the evaluation of pharmacokinetic properties of N-(4-phenylmonosubstituted)-2-cyanoacetamides as potential bioactive molecules.

This study investigates the potential of dandelion (Taraxacum officinale) root ethanol extract as a green corrosion inhibitor for two types of steel (TH-550 and TS-275) in a chloride-rich environment. Steel samples were chemically prepared and immersed in a 3% NaCl solution, both without and with the extract at concentrations of 0.5, 1.0, and 1.5 g/L. Morphology and composition of steel samples after 24 h in blank and inhibited solutions, examined by SEM and EDX, revealed the inhibitive effect of dandelion extract, since corrosion products were not visible on the steel surfaces after 24 h in the inhibited solution, unlike the blank steel surfaces. Based on the weight loss, dandelion extract inhibited corrosion processes of S2 in a chloride-rich environment at all examined concentrations; on the other hand, it acted as a corrosion inhibitor of S1 in 3% NaCl only at the concentrations of 1.0 and 1.5 g/L. According to corrosion current, corrosion potential and polarization resistance determined by potentiodynamic tests, dandelion root extract is a mixed corrosion inhibitor with a dominant anodic reaction, which decreases corrosion rate by adsorbing onto anodic sites and prevents steel dissolution. According to ATR-FTIR analysis, hydroxyl groups within the inulin molecule could act as the dominant metal-complexing groups. Therefore, the adsorption properties of dandelion root extract are most probably related to this specific site. Based on electrochemical impedance spectroscopy, the enhancement of corrosion resistance in the steel samples was evident in all the inhibited solutions examined compared to a pure 3% NaCl solution.

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.

The selected diphenylacetamide derivatives were subjected to chromatographic and in silico approach in order to obtain significant information about their structure-activity relationships. As an early step in the assessment of their biological profile, drug-likeness and lead-likeness rules were performed, as well as determination of the bioactivity scores. The relationships between the obtained chromatographic parameters and the relevant software lipophilicity/pharmacokinetic/toxicity predictors of the studied derivatives were examined by linear regression and multivariate methods. Beside the satisfactory linear relationships obtained for each applied system, the multivariate methods gave more concrete relations between the analyzed parameters of biological activity. Higher similarity between the chromatographic parameters (R_M⁰, C₀), standard measure of lipophilicity and pharmacokinetic predictors was confirmed, while the chromatographic parameter m obtained in the same conditions exhibits better agreement with the bioactivity scores and toxicity parameters. Also, it was observed that the values of diphenylacetamide’s biological activity parameters are in the greatest extent conditioned by the polarity of the substituent presented in its molecule. Graphical Abstract