RESUMO
Two series of rhodanine-3-acetic and rhodanine-3-propionic acids derivatives having benzylidene and cinnamylidene substituents with additional electron donating and withdrawing groups at the C-5 position, were synthesised. The structures of the obtained derivatives were confirmed by spectroscopic methods and their lipophilicity was screened. The crystal structures were determined for selected compounds. The antibacterial activity of the derivatives was depended on the type of carboxyalkyl group in the N-3 position and on the type of the substituent in the C-5 position. The derivatives of rhodanine-3-propionic acid demonstrated the highest activity against Gram-positive bacteria. However, none of tested derivatives showed activity against Gram-negative bacteria and yeast. We believe that the presence of the N,N-diethylamine group in the aromatic system and the number of carbon atoms in the carboxyalkyl group is more significant for the biological activity than the fact that the benzylidene or cinnamylidene substituent was present at the C-5 position.
RESUMO
The Oscik's equation based on the theory of conformal solutions was used to describe the chromatographic process in RP-HPLC. Theoretically calculated values of the logarithms of retention factors (logk) were compared with experimental values for a group of aromatic substances, i.e. alkylbenzenes, PAHs, and polar benzene derivatives. Studies were conducted using two columns: RP-18 and RP-4, as well as water-methanol and water-acetonitrile mixtures as mobile phases. The applicability of Everett's equation to describe the composition of surface phase was also verified. For this purpose, the excess methanol adsorption isotherm on LiChrospher RP-18e, was experimentally determined.
