An Overview of Pyridazinone Analogs: Chemical and Pharmacological Potential.

Pyridazinones are classical molecules that occupy an important place in heterocyclic chemistry, and since their discovery, they have been widely developed. The introduction of new functional groups into pyridazinone structures has enabled the synthesis of a large diversity of compounds. The pharmacological and agrochemical importance of pyridazinone derivatives has aroused the interest of chemists and directed their research toward the synthesis of new compounds with the aim of improving their biological effectiveness. In this review, we have compiled and discussed the different synthetic routes, reactivity, and pharmacological and agrochemical applications of the pyridazinone ring.

Reactive Oxygen Species-Mediated Apoptosis and Cytotoxicity of Newly Synthesized Pyridazin-3-Ones In P815 (Murin Mastocytoma) Cell Line.

BACKGROUND: In cancer cells, the intracellular antioxidant capacity and the redox homeostasis are mainly maintained by the glutathione- and thioredoxin-dependent systems which are considered as promising targets for anticancer drugs. Pyridazinones constitute an interesting source of heterocyclic compounds for drug discovery. The present investigation focused on studying the in-vitro antitumor activity of newly synthesized Pyridazin-3(2h)-ones derivatives against P815 (Murin mastocytoma) cell line. METHODS: The in-vitro cytotoxic activities were investigated toward the P815 cell line using tetrazolium-based MTT assay. Lipid peroxidation and the specific activities of antioxidant enzymes were also determined. RESULTS: The newly compounds had a selective dose-dependent cytotoxic effect without affecting normal cells (PBMCs). Apoptosis was further confirmed through the characteristic apoptotic morphological changes and DNA fragmentation. Two compounds (6F: and 7H: ) were highly cytotoxic and were submitted to extend biological testing to determine the likely mechanisms of their cytotoxicity. Results showed that these molecules may induce cytotoxicity via disturbing the redox homeostasis. Importantly, the anticancer activity of 6F: and 7H: could be due to the intracellular reactive oxygen species hypergeneration through significant loss of glutathione reductase and thioredoxin reductase activities. This eventually leads to oxidative stress-mediated P815 cell apoptosis. Furthermore, the co-administration of 6F: or 7H: with Methotrexate exhibited a synergistic cytotoxic effect. CONCLUSIONS: considering their significant anticancer activity and chemosensitivity, 6F: and 7H: may improve the therapeutic efficacy of the current treatment for cancer.

Cytotoxicity of new pyridazin-3(2H)-one derivatives orchestrating oxidative stress in human triple-negative breast cancer (MDA-MB-468).

Triple-negative breast cancer (TNBC) is a complex and aggressive subtype of breast cancer characterized by high morbidity and mortality. In the absence of targeted therapy, only chemotherapy is available in this case of cancer. The current study investigated the antitumor effect of new pyridazin-3(2H)-one derivatives on the human TNBC cell line, MD-MB-468. The in vitro cytotoxic activities were investigated using the tetrazolium-based MTT assay. Lipid peroxidation, H2 O2 content, and the specific activities of antioxidant enzymes were also determined. Two molecules, 6f and 7h, were found to be selectively highly active against tumor cells with IC50 values of 3.12 and 4.9 µM, respectively. Furthermore, cells exposed to 6f showed a significant increase in H2 O2 and lipid peroxidation levels, accompanied by a decrease in the enzyme activities of glutathione reductase (GR) and thioredoxin reductase (TrxR). The cytotoxicity of the compound 6f may improve the therapeutic efficacy of the current treatment for TNBC via the inhibition of GR and TrxR activities.

Crystal structure of ethyl 2-{4-[(5-chloro-1-benzo-furan-2-yl)meth-yl]-3-methyl-6-oxo-1,6-di-hydro-pyridazin-1-yl}acetate.

In the title compound, C18H17ClN2O4, the dihedral angle between the benzofuran ring system [maximum deviation 0.014 (2) Å] and the oxopyradizine ring is 73.33 (8)°. The structure is characterized by disorder of the ethyl group, which is split into two parts, with a major component of 0.57 (3), and the acetate carbonyl O atom, which is statistically disordered. In the crystal, the molecules are linked by C-H⋯O inter-actions, forming a three-dimensional network.