Design, Synthesis, and Characterization of Novel Substituted 1,2,4-Triazines: Cytotoxic Activity on HepG2 and HT-29 Cell Lines, Enzyme Inhibition, and Molecular Docking Studies.

1,2,4-Triazines exhibit various pharmacological properties due to their strong biological activities, such as anticancer, anti-inflammatory, antimicrobial, antiviral, and antioxidant, and also occupy an important place in the pharmaceutical field. The tested compounds were synthesized and characterized. 1,2,4-Triazines were evaluated for their inhibitory and cytotoxicity effects on acetylcholinesterase (AChE), glutathione S-transferase (GST), human liver cancer cell line (HepG2), and human colorectal adenocarcinoma cell line (HT-29). 1,2,4-Triazines (3a-c, 5, 6, 10) were found to inhibit these enzymes with IC50 values ranging from 1.41 to 4.28 μM for AChE and from 1.58 to 4.13 μM for GST. 1,2,4-Triazine compounds were tested in range of 12.5-100 µM concentrations against HepG2 and HT-29 cell lines. Among the 1,2,4-triazines tested, 10 was the most effective substance on HepG2 cells, especially at high doses, while 3b was effective on HT-29. Furthermore, molecular docking results indicated that the 1,2,4-triazines showed strong binding and stability at the active site of enzymes and selected proteins. 1,2,4-Triazines may serve as promising precursors for the design of potent enzyme inhibitors and anticancer agents.