A multi-functional composite nanocatalyst for the synthesis of biologically active pyrazolopyranopyrimidines: Multifaceted antimicrobial, antioxidant, and anticancer activities

Metal-organic frameworks (MOFs) are crystalline entities made up of metal ions or clusters coordinated to typically rigid organic molecules, creating three-dimensional porous networks. The integration of both inorganic and organic components results in almost unlimited chemical and structural possibilities. This potential has led to MOF for catalytic applications attracting great interest. In this context, a novel multifunctional magnetic nanocomposite, was synthesized for the efficient and sustainable production of biologically active pyrazolopyranopyrimidines. This composite (Fe₃O₄@PmPDA@UiO-66-NH₂) combines the advantages of magnetic nanoparticles (Fe₃O₄), a polymer coating poly(meta-phenylenediamine), and a metal-organic framework (UiO-66-NH₂). The nanocomposite as a multifunctional magnetic catalyst has been synthesized in three steps including (1) synthesis of Fe₃O₄ nanoparticles by co-precipitation technique (2) preparation of UiO-66-NH₂ through a solvothermal method, (3) preparation of nanoparticles-polymer-MOF hybrid nanocomposite using Fe₃O₄, PmPDA, and UiO-66-NH₂. The prepared catalyst was fully characterized by XRD, FTIR, EDX, FESEM, TGA, and VSM analyses. The Fe₃O₄@PmPDA@UiO-66-NH₂ nanocomposite was used as a catalyst for the synthesis of pyrazolopyranopyrimidines. Various pyrazolopyranopyrimidine products were synthesized in remarkable yields (90–96%) in a short reaction time (10–80 min). The biological activity of pyrazolopyranopyrimidines was studied. The anticancer evaluation of some pyrazolopyranopyrimidines was studied on the survival rate of HepG2 cancer cells and NIH/3T3 fibroblast cells by using an MTT assay. A greater inhibition of cell viability was obtained after 48 h of incubation with higher concentrations (150 µg/L) of pyrazolopyranopyrimidines compounds, demonstrating the anti-proliferative effects of these agents. Additionally, in most cases, the viability of fibroblast cells exhibited a comparatively minor decline when incubated with pyrazolopyranopyrimidines as opposed to HepG2 cells. Furthermore, these compounds have an antioxidant activity between 85.3 and 98.3%. Additionally, their antimicrobial activity was evaluated using the Kirby-Bauer disk diffusion method and showed the highest inhibition zone against Staphylococcus aureus and Escherichia coli of 19 ± 2.0 and 10 ± 1.5 mm, respectively.