Title:Metal Complexes as Promising Agents for Biomedical Applications
Volume: 27
Issue: 31
Author(s): Natalia V. Loginova*, Hleb I. Harbatsevich, Nikolai P. Osipovich, Galina A. Ksendzova, Tatsiana V. Koval’chuk and Genrikh I. Polozov
Affiliation:
- Faculty of Chemistry, Belarusian State University, Minsk,Belarus
Keywords:
Redox-active metal complexes, biometals, diphenols, antimicrobial activity, ferricytochrome c, SODlike
activity.
Abstract:
Background: In this review article, a brief overview of novel metallotherapeutic agents
(with an emphasis on the complexes of essential biometals) promising for medical application is
presented. We have also focused on the recent work carried out by our research team, specifically
the development of redox-active antimicrobial complexes of sterically hindered diphenols with some
essential biometals (copper, zinc, nickel).
Results: The complexes of essential metals (manganese, iron, cobalt, nickel, copper, zinc) described
in the review show diverse in vitro biological activities, ranging from antimicrobial and antiinflammatory
to antiproliferative and enzyme inhibitory. It is necessary to emphasize that the type of
organic ligands in these metal complexes seems to be responsible for their pharmacological
activities. In the last decades, there has been a significant interest in synthesis and biological
evaluation of metal complexes with redox-active ligands. A substantial step in the development of
these redox-active agents is the study of their physicochemical and biological properties, including
investigations in vitro of model enzyme systems, which can provide evidence on a plausible
mechanism underlying the pharmacological activity. When considering the peculiarities of the
pharmacological activity of the sterically hindered diphenol derivatives and their nickel(II),
copper(II) and zinc(II) complexes synthesized, we took into account the following: (i) all these
compounds are potential antioxidants and (ii) their antimicrobial activity possibly results from their
ability to affect the electron-transport chain.
Conclusion: We obtained novel data demonstrating that the level of antibacterial and antifungal
activity in the series of the above-mentioned metal-based antimicrobials depends not only on the
nature of the phenolic ligands and complexing metal ions, but also on the lipophilicity and reducing
ability of the ligands and metal complexes, specifically regarding the potential biotargets of their
antimicrobial action – ferricytochrome c and the superoxide anion radical. The combination of
antibacterial, antifungal and antioxidant activity allows one to consider these compounds as
promising substances for developing therapeutic agents with a broad spectrum of activities.
