In this study, the crude extract and its isolated compounds from the stem bark of Annickia chlorantha were tested for their larvicidal, developmental, and repellent activity against the mosquito vector, Culex pipiens, besides their toxicity to the non-target aquatic organism, the zebrafish (Danio rerio). The acute larvicidal activity of isolated compounds; namely, palmatine, jatrorrhizine, columbamine, β-sitosterol, and Annickia chlorantha methanolic extract (AC), was observed. Developmentally, the larval duration was significantly prolonged when palmatine and β-sitosterol were applied, whereas the pupal duration was significantly prolonged for almost all treatments except palmatine and jatrorrhizine, where it shortened from those in the control. Acetylcholinesterase (AChE) enzyme showed different activity patterns, where it significantly increased in columbamine and β-sitosterol, and decreased in (AC), palmatine, and jatrorrhizine treatments, whereas glutathione S-transferase (GST) enzyme was significantly increased when AC methanolic extract/isolated compounds were applied, compared to the control. The adult emergence percentages were significantly decreased in all treatments, whereas tested compounds revealed non-significant (p > 0.05) changes in the sex ratio percentages, with a slight female-to-male preference presented in the AC-treated group. Additionally, the tested materials revealed repellence action; interestingly, palmatine and jatrorrhizine recorded higher levels of protection, followed by AC, columbamine, and β-sitosterol for 7 consecutive hours compared to the negative and positive control groups. The non-target assay confirms that the tested materials have very low toxic activity compared to the reported toxicity against mosquito larvae. A docking simulation was employed to better understand the interaction of the isolated compounds with the enzymes, AChE and GST. Additionally, DFT calculations revealed that the reported larvicidal activity may be due to the differing electron distributions among tested compounds. Overall, this study highlights the potential of A. chlorantha extract and its isolated compounds as effective mosquitocidal agents with a very low toxic effect on non-target organisms.

Background: Alzheimer’s disease (AD) is characterized by cholinergic dysfunction, making the inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) critical for improving cholinergic neurotransmission. However, the development of effective dual inhibitors remains challenging. Objective: This study aims to synthesize and evaluate novel pyridazine-containing compounds as potential dual inhibitors of AChE and BuChE for AD treatment. Methods: Ten novel pyridazine-containing compounds were synthesized and characterized using IR, ¹H NMR, and ¹³C NMR. The inhibitory activities against AChE and BuChE were assessed in vitro, and pharmacokinetic properties were explored through in silico ADME studies. Molecular dynamics simulations were performed for the most active compound. Results: Compound 5 was the most potent inhibitor, with IC₅₀ values of 0.26 µM for AChE and 0.19 µM for BuChE, outperforming rivastigmine and tacrine, and showing competitive results with donepezil. Docking studies revealed a binding affinity of −10.21 kcal/mol to AChE and −13.84 kcal/mol to BuChE, with stable interactions confirmed by molecular dynamics simulations. In silico ADME studies identified favorable pharmacokinetic properties for compounds 5, 8, and 9, with Compound 5 showing the best activity. Conclusions: Compound 5 demonstrates strong potential as a dual cholinesterase inhibitor for Alzheimer’s disease, supported by both in vitro and in silico analyses. These findings provide a basis for further optimization and development of these novel inhibitors.

In this strategy, we attempt to design various novel nitrogen-rich heterocycles in one molecule. Green, simple, and efficient aza-annulations of an active, versatile building block, 1-amino-4-methyl-2-oxo-6-phenyl-1,2-dihydropyridine-3-carbonitrile (1), with different bifunctional reagents were developed under solvent-free conditions, resulting in the bridgehead tetrazines and azepines (triazepine and tetrazepines). Pyrido[1,2,4,5]tetrazines have been synthesized through two pathways; [3 + 3]- and [5 + 1]-annulations. In addition, pyrido-azepines have been developed by applying [4 + 3]-and [5 + 2]-annulations. This protocol establishes an efficient technique for synthesizing essential biological derivatives of 1,2,4,5-tetrazines, 1,2,4-triazepines, and 1,2,4,5-tetrazepine, tolerating a diverse variety of functionalities without the need for catalysis and fast reaction rates in high yields. The National Cancer Institute (NCI, Bethesda, USA) examined twelve compounds produced at a single high dosage (10⁻⁵ M). Compounds4,8, and9were discovered to have potent anticancer action against certain cancer cell types. To explain NCI results, the density of states was calculated to conduct a better description of the FMOs. The molecular electrostatic potential maps were created to explain a molecule's chemical reactivity. In silico ADME experiments were performed to better understand their pharmacokinetic characteristics. Finally, the molecular docking investigations on Janus Kinase-2 (PDB ID:4P7E) were carried out to study the binding mechanism, binding affinity, and non-bonding contacts.

Under catalyst-free conditions, an environmentally friendly synthesis of a class of spiropyrane, spiropyranopyrazole, spirobenzofurane, spirobenzofuropyrazole, spirooxadiazolidine, spiro-triazolooxadiazole, spirotriazole, and spirophenanthrene from isatin and different reagents was designed, synthesized, and evaluated for their anticancer activities. Compounds 3, 4, and 9 were formed via a one-pot three-component fusion, and the process of synthesis was interpreted using Knoevenagel condensation, Michael addition, and intramolecular cyclization. The technique of preparation has important benefits such as simple reaction conditions, an easy work-up method, simple separation, and nonchromatographic purification of the products. The ¹H, ¹³C-NMR, and mass spectra of the investigated compounds (2–10) were estimated and matched rather well with the experimental results. The National Cancer Institute (NCI, Bethesda, USA) examined all produced derivatives and found that compound 3 had high anti-cancer cell line activity against non-small cell lung-HCI-H522 (GI% = 93.52%) and melanoma-LOX IMVI (GI%=71.63%). Compounds 7 and 8 also showed inhibitory action, with mean GI% ranging from 9.63% to 35.90%. While Compound 10 demonstrated efficacy against a variety of cell lines representing multiple tumor subpanels, with GI% equal to or more than 40%. Docking experiments with Tyrosine Kinase (PDB ID: 2J5F) were carried out to validate NCI findings. In silico investigations revealed that the majority of the produced spiro compounds satisfied Lipinski’s criteria. Graphical Abstract