Carbohydrate-metal complexes and their potential as anticancer agents
A review. Platinum complex-based chemotherapy is one of the major treatment options of many malignancies. Although severe side effects occur, and only a limited spectrum of tumors can be cured, Pt compds. are used in every second therapy scheme. Thus, many different drug design strategies have been employed for improving the properties of anticancer drugs including pH or redox activation in the tumor, variation of the metal center and therefore the redox and ligand exchange properties, the application of multinuclear metal complexes, the development of targeted approaches, etc. Application of carbohydrate-metal complexes is an example of a targeted approach exploiting the biochem. and metabolic functions of diverse sugars in living organisms for transport and accumulation. Natural carbohydrates and synthetic derivs. possess a manifold of donors endowing them with the ability to coordinate metal centers and providing some addnl. advantages over other ligands, e.g., biocompatibility, nontoxicity, enantiomeric purity, water soly., and well-explored chem. In recent years, several examples of carbohydrate compds. have been developed for diverse medicinal applications ranging from compds. with antibiotic, antiviral, or fungicidal activity and anticancer compds. Herein, metal complexes with carbohydrate ligands are reviewed and the role of the carbohydrate carriers on the antineoplastic activity of these compds., both in vitro and in vivo, is described.