Recent Advances in Cancer Drug Discovery using Bidentate ligand complexes

David Izuchukwu Ugwu and Jeanet Conradie

Department of Chemistry, University of the Free State, Bloemfontein 9300, South Africa; E-mail: ugwu.di@ufs.ac.za

Introduction

Cancer is a fatal illness that occurs when cells in an organ or tissue are divided and multiplied irregularly and indiscriminately. Globally, it is the second leading cause of death (after cardiovascular diseases) and was responsible for over 9.6 million deaths in 2018. A tumor could be benign when the abnormal mass formed does not spread or invade nearby tissues, cells, or organs while cancerous tumors are when the abnormal mass formed can spread to other cells, tissues, or organs. Bidentate ligands are neutral or negatively charged species with two donor atoms capable of forming a ring system usually called chelates with metal ions. The donor atoms can be O, N, S, P, C etc, and each donates a pair of electrons to the central metal atom.

Dithiocarbamates (1) are distinctly structured molecules coordinating with the sulfur atoms and are very easy to functionalize due to the presence of a nitrogen atom. Ronconi and co-workers at the Padua reported gold dithiocarbamate complex (2) with 0.001 μM IC50 against human leukemic promyelocytes (HL60), human malignant melanoma (MeWo), human Burkitt’s lymphoma (Daudi) while cisplatin had 25.6, 48, and 95 μM IC50 respectively.