Nickel Ferrite (NiFe2O4) Nanoparticles as Magnetically Recyclable Nanocatalyst for Highly Efficient Synthesis of 4H-Chromene Derivatives.

An adapted one-pot route to nanocatalyst-assisted synthesis of 4H-chromenes via three component condensation reaction between dimedone, malononitrile, and a broad range of aryl aldehydes by the use of magnetic nickel ferrite nanoparticles is described. By this achievement, not only a novel route to highly efficient synthesis of these series of heterocycles was introduced but also the scope of these medicinally important products was developed via preparation of some novel products. Above all, a new application of nickel ferrite nanoparticles (NiFe2O4 NPs) as highly efficient, green and magnetically recyclable catalyst has been introduced. Overall, obtaining good to excellent yields of products, environmentally and economic benign procedure, easy handling, availability of starting materials, use of non-toxic solvents, and high recyclability of nano-catalyst could be countered as most important advantages of this methodology.

Design, synthesis, biological evaluation, and molecular dynamics of novel cholinesterase inhibitors as anti-Alzheimer's agents.

A series of novel chroman-4-one derivatives were designed and synthesized successfully with good to excellent yield (3a-l). In addition, the obtained products were evaluated for their cholinesterase (ChE) inhibitory activities. The results show that among the various synthesized compounds, analogs bearing the piperidinyl ethoxy side chain with 4-hydroxybenzylidene on the 3-positions of chroman-4-one (3l) showed the most potent activity with respect to acetylcholinesterase (anti-AChE activity; IC50 = 1.18 µM). In addition, the structure-activity relationship was studied and the results revealed that the electron-donating groups on the aryl ring of the 3-benzylidene fragment (3k, 3l) resulted in the designed compounds to be more potent ChE inhibitors in comparison with those having electron-withdrawing groups (3h). In this category, the strongest ChE inhibition was found for the compound containing piperidine as cyclic amine, and a hydroxyl group (for AChE, compound 3l) and fluoro group (for butyrylcholinesterase (BuChE, compound 3i) on the para-position of the aryl ring of the benzylidene group. The molecular docking and dynamics studies of the most potent compounds (3i and 3l against BuChE and AChE, respectively) demonstrated remarkable interactions with the binding pockets of the ChE enzymes and confirmed the results obtained through in vitro experiments.