Mechanistic Insights into the Antioxidant and Antimicrobial Activities of Transition Metal-Thiosemicarbazone Complexes

• Author(s): Dr. N. Y. Badannavar
• Paper ID: 1703810
• Page: 225-235
• Published Date: 30-09-2022
• Published In: Iconic Research And Engineering Journals
• Publisher: IRE Journals
• e-ISSN: 2456-8880
• Volume/Issue: Volume 6 Issue 3 September-2022

Abstract

This study explores the mechanistic underpinnings of the antioxidant and antimicrobial activities of transition metal-thiosemicarbazone (TSC) complexes through a detailed conceptual framework combining theoretical analyses and literature-driven insights, where the antioxidant potential is hypothesized to arise from the ability of the complexes to participate in redox cycling via reversible one-electron transfer processes facilitated by the metal center, while the TSC ligand provides stabilization of the reactive intermediates through resonance and inductive effects, and the antimicrobial activity is attributed to the disruption of microbial cell membrane integrity by the complexes via enhanced lipophilicity due to metal coordination that enables facile penetration and binding to intracellular targets such as DNA, proteins, or enzymes, disrupting essential metabolic pathways and cellular replication mechanisms, and the theoretical analysis emphasizes the role of electronic, steric, and geometric factors in dictating the activity, supported by computational data indicating that complexes with certain transition metals, such as Cu(II), Zn(II), and Fe(III), exhibit superior reactivity due to optimal orbital overlap and charge transfer interactions, while the ligand scaffold modulates the metal ion reactivity through electron-donating or withdrawing substituents, thereby influencing the redox potential, antimicrobial spectrum, and selectivity of the complexes, and the work integrates density functional theory (DFT) studies to predict the electronic distribution and binding affinity of the complexes with microbial DNA and reactive oxygen species (ROS), correlating these properties with experimental data from previous studies reporting minimum inhibitory concentration (MIC) values in the range of 1-10 ?g/mL against gram-positive and gram-negative bacteria, alongside DPPH radical scavenging activity reaching 90% inhibition at micromolar concentrations, and the theoretical framework also considers the influence of solubility, stability, and pH on the activity profile, proposing a dual mechanistic model involving ROS generation for oxidative damage and direct interaction with microbial biomolecules, culminating in a comprehensive understanding that establishes transition metal-thiosemicarbazone complexes as promising candidates for therapeutic applications targeting oxidative stress and multidrug-resistant infections, with a focus on future strategies for optimizing their efficacy through rational ligand design and precise metal selection.

Keywords

Transition Metal Complexes, Thiosemicarbazones (TSC), Antioxidant Activity, Antimicrobial Mechanism, Density Functional Theory (DFT), Reactive Oxygen Species (ROS)

Citations

IRE Journals:
Dr. N. Y. Badannavar "Mechanistic Insights into the Antioxidant and Antimicrobial Activities of Transition Metal-Thiosemicarbazone Complexes" Iconic Research And Engineering Journals Volume 6 Issue 3 2022 Page 225-235

IEEE:
Dr. N. Y. Badannavar "Mechanistic Insights into the Antioxidant and Antimicrobial Activities of Transition Metal-Thiosemicarbazone Complexes" Iconic Research And Engineering Journals, 6(3)