In this contribution, four new compounds synthesized from 4-hydroxycoumarin and tyramine/octopamine/norepinephrine/3-methoxytyramine are characterized spectroscopically (IR and NMR), chromatographically (UHPLC-DAD), and structurally at the B3LYP/6-311++G*(d,p) level of theory. The crystal structure of the 4-hydroxycoumarin-octopamine derivative was solved and used as a starting geometry for structural optimization. Along with the previously obtained 4-hydroxycoumarin-dopamine derivative, the intramolecular interactions governing the stability of these compounds were quantified by NBO and QTAIM analyses. Condensed Fukui functions and the HOMO-LUMO gap were calculated and correlated with the number and position of OH groups in the structures. In vitro cytotoxicity experiments were performed to elucidate the possible antitumor activity of the tested substances. For this purpose, four cell lines were selected, namely human colon cancer (HCT-116), human adenocarcinoma (HeLa), human breast cancer (MDA-MB-231), and healthy human lung fibroblast (MRC-5) lines. A significant selectivity towards colorectal carcinoma cells was observed. Molecular docking and molecular dynamics studies with carbonic anhydrase, a prognostic factor in several cancers, complemented the experimental results. The calculated MD binding energies coincided well with the experimental activity, and indicated 4-hydroxycoumarin-dopamine and 4-hydroxycoumarin-3-methoxytyramine as the most active compounds. The ecotoxicology assessment proved that the obtained compounds have a low impact on the daphnia, fish, and green algae population.

Four trans chelate N,O-palladium(II) complexes were synthetized starting from salicylaldehyde anil Schiff bases, as ligands. Their structures were elucidated using experimental and theoretical tools. The structures of the theoretically possible cis isomers are examined using the DFT method. The biological activity, in vitro cytotoxic and prooxidative effects against human breast carcinoma MDA-MB-231, human colon carcinoma HCT-116, and human fibroblast healthy MRC-5 cell lines of investigated compounds were determined. Schiff bases show a moderate or weak cytotoxic effect. On the other hand, complexes Pd-1 and Pd-6 show a significant cytotoxic effect on all three cell lines, with IC₅₀ values in the range of 0.6 to 17.1 μM on HCT-116 cells, 7.2 to 55.6 μM on MDA-MB-231 cells and 34.5 to 48.1 μM on MRC-5 cells. Also, Pd-1 and Pd-6 induce extreme oxidative stress in the all treated cell lines. At this stage of investigation, Pd-1 and Pd-6 showed no selectivity towards cancer cells, i.e. they were also cytotoxic to MRC-5 cells to a similar extent. Taking into account these facts, it could be further investigated how the most active substances impact on the type of cell death (apoptotic and/or necrotic pathways).