Novel heterocyclic compounds containing pyrazole, thiazole and pyridine moieties were designed and prepared based on the condensation reaction between 1,3-thiazole or aminopyridine derivatives and 1H-pyrazole,3,5-dimethyl-1H-pyrazole or 1,2,4-triazole. Their structures were confirmed with FTIR, ¹H and ¹³C NMR analyses. DPPH scavenging assay was used to evaluate their antioxidant potential. The ligand 4 showed the best antioxidant activity with an IC₅₀ = 4.67 μg/mL, while IC₅₀ values of the other compounds were found to be ranging from 20.56 to 45.32 μg/mL. DFT and molecular docking studies were performed in order to gain better insights and to understand the relationship between the structures of the studied compounds and their antioxidant activities. The results obtained revealed a good agreement between the experimental and the theoretical findings.

Two new tripodal compounds—4-{bis[(3,5-dimethyl-1H-pyrazole-1-yl)methyl]amino}butane-1-ol (1); ethyl 1-[((2-hydroxyethyl){[3-(ethoxycarbonyl)-5-methyl-1H-pyrazole-1-yl]methyl} amino)methyl]-5-methyl-1H-pyrazole-3-carboxylate (2) were reported. The evaluation of the cytotoxic properties in vitro of these ligands, was examined on two tumor cell lines—P815 (mastocytome murine) and Hep (carcinoma of human larynx). The concentration required to induce 50% of lysis (IC₅₀) was more pronounced against P815 cell line (IC₅₀: 39.42 µg mL⁻¹ for the compound 1 and 97.74 µg mL⁻¹ for the compound 2) than the Hep cell line (IC₅₀: 83.49 µg mL⁻¹ for compound 1 and 185.30 µg mL⁻¹ for compound 2). Statistical analysis shows that the compound 1 is two to three folds more cytotoxic than the compound 2 (p < 0.05). Interestingly, the cytotoxic activity depends strongly on both the substituents linked to the aminic nitrogen and pyrazolic rings.