Multifunctional Organoiron Dendrimers Functionalized with Zingerone: Synthesis, Characterization, and Promising Biomedical Applications

Abstract

Organoiron dendrimers of three generations were synthesized via a divergent synthetic methodology starting from the pentaerythritol tetrakis (3-mercaptopropionate) core. These dendrimers were functionalized with zingerone, a natural compound renowned for its potent antioxidant and anti-inflammatory properties. Comprehensive characterizations were performed using a range of standard techniques, including 1H and 13C NMR spectroscopy, scanning electron microscopy, cyclic voltammetry, and thermogravimetric analysis. The thermogravimetric analysis results revealed a two-step degradation process: the initial phase corresponded to the detachment of cyclopentadienyliron moieties. In contrast, the second phase involved the decomposition of the organic framework. Higher-generation dendrimers demonstrated increased thermal stability, requiring elevated temperatures for the second degradation stage, demonstrating a clear correlation between molecular weight and stability. Electrochemical analyses revealed progressively more negative shifts and increased peak intensities in the reduction and oxidation peaks of higher-generation dendrimers, suggesting an increased density of electrochemically active sites. The scanning electron microscopy analysis revealed predominantly amorphous morphologies in the dendrimers, with higher-generation variants forming larger, crystalline aggregates characterized by sharply defined edges. Biological evaluations underscored the remarkable potential of the dendrimers. The third-generation dendrimer functionalized with zingerone exhibited superior antioxidant, antimicrobial, and antifungal activities compared to reference drugs. Meanwhile, the first-generation dendrimer demonstrated the most pronounced anti-inflammatory activity, although higher-generation dendrimers also delivered excellent results, particularly at higher concentrations. These results highlight the multifunctional properties of the synthesized organoiron dendrimers, paving the way for their application in biomedical and pharmaceutical fields.