Synthesis, crystal structures and biological evaluation of new pyridazine derivatives

Recent contributions of pyridazine as a privileged scaffold of anticancer agents in medicinal chemistry: An updated review

Pyridazine, as a privileged scaffold, has been extensively utilized in drug development due to its multiple biological activities. Especially around its distinctive anticancer property, a massive number of pyridazine-containing compounds have been synthesized and evaluated that target a diverse array of biological processes involved in cancer onset and progression. These include glutaminase 1 (GLS1) inhibitors, tropomyosin receptor kinase (TRK) inhibitors, and bromodomain containing protein (BRD) inhibitors, targeting aberrant tumor metabolism, cell signal transduction and epigenetic modifications, respectively. Pyridazine moieties functioned as either core frameworks or warheads in the above agents, exhibiting promising potential in cancer treatment. Therefore, the review aims to summarize the recent contributions of pyridazine derivatives as potent anticancer agents between 2020 and 2024, focusing mainly on their structure-activity relationships (SARs) and development strategies, with a view to show that the application of the pyridazine scaffold by different medicinal chemists provides new insights into the rational design of anticancer drugs.

Ligand-based designing of DPP-4 inhibitors via hybridization; synthesis, docking, and biological evaluation of pyridazine-acetohydrazides

A series of novel pyridazine-acetohydrazide hybrids were designed, synthesized, and evaluated for their in vitro and in vivo antihyperglycemic activity. In this context, pyridazine-acetohydrazides (6a-6p) were synthesized by coupling substituted aldehyde with 2-(5-cyano-6-oxo-3,4-diphenylpyridazine-1-6H-yl) acetohydrazide, which was prepared via the reaction of pyridazine ester with hydrazine hydrate. The molecular docking study was carried out to examine the binding affinities and interaction of designed compounds against the DPP-4 enzyme. Compounds 6e, 6f, 6l, and 6n exhibited interaction with active residue. In silico ADMET properties, and toxicity studies corroborated that compounds were found to have good bioavailability and less toxic. The synthesized compounds were further estimated for in vitro DPP-4 activity. Compounds 6e and 6l were found as the most effective DPP-4 inhibitor in this series with IC50 values (6.48, 8.22 nM) when compared with sitagliptin (13.02 nM). According to the toxicity assay compound, 6l showed very less toxicity at a higher concentration so further selected for the in vivo antihyperglycemic activity.

Synthesis, α-Glucosidase inhibitory activity and docking studies of Novel Ethyl 1,2,3-triazol-4-ylmethylthio-5,6-diphenylpyridazine-4-carboxylate derivatives

In this work, a novel series of pyridazine-triazole hybrid molecules were prepared and evaluated as inhibitors of rat intestinal α-glucosidase enzyme. Amongst all newly synthesized compounds, 10k showed good inhibition in the series with IC₅₀ value of 1.7 µM which is 100 folds stronger than positive control, acarbose. The cytotoxicity revealed that this compound is not toxic against normal cell line, HDF. The docking studies showed that triazole ring plays an important role in the binding interactions with the active site. The insertion of compound 10k into the active pocket of α-glucosidase and formation of hydrogen bonds with Leu677 was observed from docking studies. The kinetic studies revealed that this compound has uncompetitive mode of inhibition against α-glucosidase enzyme.

Synthesis and biological evaluation of novel benzo[a]pyridazino[3,4-c]phenazine derivatives

A convenient microwave-assisted one-pot four-component synthetic approach was developed en route to novel functionalized benzo[a]pyridazino[3,4-c]phenazine derivatives starting from 2-hydroxy-1,4-naphthoquinone, aromatic aldehydes, methyl hydrazine and o-phenylenediamine. Nine new derivatives were successfully synthesized and subsequently evaluated in terms of their biological profiles. The results revealed good cytotoxic activities of compounds 6a, 6h against KB, HepG2, Lu1 and MCF7 human cancer cell lines. Besides that, compound 6d exhibited promising antimicrobial activities toward Staphylococcuc aureus and Bacillus subtilis bacterial strains with IC₅₀ < 6 μM.

Synthesis, in-vitro evaluation, molecular docking, and kinetic studies of pyridazine-triazole hybrid system as novel α-glucosidase inhibitors

In this study, we reported the discovery of pyridazine based 1,2,3-triazole derivatives as inhibitors of α-glucosidase. All target compounds exhibited significant inhibitory activities against yeast and rat α-glucosidase enzymes compared to positive control, acarbose. The most potent compound 6j, ethyl 3-(2-(1-(4-nitrobenzyl)-1H-1,2,3-triazol-4-yl)ethyl)-5,6-diphenylpyridazine-4-carboxylate exhibited IC₅₀ values of 58, and 73 µM. Docking studies indicated the responsibility of hydrophobic and hydrogen bonding interactions in the ligand-enzyme complex stability. The in-vitro safety against the normal cell line was observed by toxicity evaluation of the selected compounds.

Pyridazine as a privileged structure: An updated review on anticancer activity of pyridazine containing bioactive molecules

Identification of potent anticancer agents with high selectivity and low toxicity remains on the way to human health. Pyridazine featuring advantageous physicochemical properties and antitumor potential usually is regarded as a central core in numerous anticancer derivatives. There are several approved pyridazine-based drugs in the market and analogues currently going through different clinical phases or registration statuses, suggesting pyridazine as a promising drug-like scaffold. The current review is intended to provide a comprehensive and updated overview of pyridazine derivatives as potential anticancer agents. In particular, we focused on their structure-activity relationship (SAR) studies, design strategies, binding modes and biological activities in the hope of offering novel insights for further rational design of more active and less toxic anticancer drugs.