We synthesized the Schiff base ligands H₂L¹–H₂L⁴ and their La(III) complexes and characterized them by the analytical and spectroscopic methods. We investigated their electrochemical and antimicrobial activity properties. The electrochemical properties of the ligands H₂L¹–H₂L⁴ and their La(III) complexes were studied at the different scan rates (100 and 200 mV), different pH ranges (), and in the different solvents. The electrooxidation of the Schiff base ligands involves a reversible transfer of two electrons and two protons in solutions of pH up to 5.5, in agreement with the one-step two-electron mechanism. In solutions of pH higher than 5.5, the process of electrooxidation reaction of the Schiff base ligands and their La(III) complexes follows an ECi mechanism. The antimicrobial activities of the ligands and their complexes were studied. The thermal properties of the metal complexes were studied under nitrogen atmosphere in the range of temperature 20–1000°C.

Rumex patientia L. is from Polygonaceae family and there are 25 species of it in Turkey. Rumex patientia L. has antifebrile, laxative, diuretic, and pain killer properties. In this study, the extraction of the Rumex patientia L. leaf were done and determination the fat content and fatty acid composition by using GC device and to determinate in vitro antimicrobial activity of their different extracts were aimed. On the purpose of detection of antimicrobial activity; Rumex patientia L. leaf was extracted with ethanol, methanol, acetone, petroleum ether and water. Rumex patientia L. leaves was tested their different extracts using Bacillus subtilis, Bacillus cereus, Escherichia coli, Pseudomonas aeroginosa, Pasteurella multocida, Yersinia enterocolitica, Klebsiella pneumoniae, Staphylococcus aureus bacteria and Candida albicans yeast by agar-well diffusion technique. As a result of the study, 26 fatty acid components were detected on Rumex patientia L. leaf. In addition, among obtained extracts the highest antimicrobial activity was formed by methyl alcohol extract on K. pneumoniae bacteria (32mm).