Abstract
Schiff base metal complexes have emerged as an important class of compounds in medicinal and coordination chemistry owing to their structural versatility, strong metal-binding ability, and diverse biological activities. The presence of the azomethine (–C=N–) functional group enables effective chelation with a wide range of transition metal ions, thereby enhancing the physicochemical stability, lipophilicity, and pharmacological potential of the parent ligands. Metal complexation often results in improved biological efficacy compared to free Schiff bases, attributed to altered electronic properties and enhanced interaction with biological targets. This review summarizes recent developments in the design, synthesis, and physicochemical characterization of novel Schiff base metal complexes. Emphasis is placed on their biological evaluation, including antimicrobial, anticancer, antioxidant, anti-inflammatory, antiviral, and enzyme inhibitory activities. The underlying mechanisms of action, structure–activity relationships (SAR), and the influence of metal ions and ligand architecture on biological performance are critically discussed. Furthermore, current challenges, toxicity considerations, and future perspectives for the development of Schiff base metal complexes as potential therapeutic agents are highlighted.
Keywords
Schiff base, metal complexes, biological evaluation, antimicrobial activity, anticancer activity, coordination chemistry
Introduction
Schiff bases are condensation products formed by the reaction of primary amines with aldehydes or ketones, characterized by the presence of an imine or azomethine functional group (–C=N–). These compounds were first reported by Hugo Schiff in 1864 and have since become an important class of ligands in coordination chemistry due to their ease of synthesis, structural diversity, and strong metal-binding ability [1]. The azomethine linkage plays a crucial role in coordination with metal ions through the lone pair of electrons on the nitrogen atom, often accompanied by other donor atoms such as oxygen or sulfur [2]. Schiff bases readily form stable complexes with transition metal ions including copper (II), zinc (II), nickel (II), cobalt (II), iron (III), and manganese (II), among others. The chelation process typically enhances the physicochemical and biological properties of the parent ligand [3]. According to chelation theory, coordination reduces the polarity of the metal ion through partial sharing of its positive charge with donor atoms, thereby increasing lipophilicity and facilitating penetration through biological membranes [4]. As a result, Schiff base metal complexes frequently exhibit superior antimicrobial, anticancer, antioxidant, and enzyme inhibitory activities compared to their free ligands [5].
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Suchita Bondre
Corresponding author
Research Scholar, Faculty of Pharmacy, Oriental University Indore MP
Deepika Gupta
Co-author
Associate Professor, Faculty of Pharmacy, Oriental University Indore MP
Suchita Bondre*, Deepika Gupta, Biological Evaluation of Novel Schiff Base Metal Complexes: A Review, Int. J. Sci. R. Tech., 2026, 3 (2), 197-207. https://doi.org/10.5281/zenodo.18661728
10.5281/zenodo.18661728
