Electrochimica Acta, Vol.302, 130-136, 2019
New mechanistic insights into osmium-based tamoxifen derivatives
The electrochemical behavior of osmociphenol (3, Oc-OH), an organometallic osmium-based anticancer drug candidate, has been investigated by cyclic voltammetry in the absence and presence of lutidine used as a base model. Osmociphenol exhibited spontaneous deprotonation of the phenol function upon oxidation of the osmocene moiety due to its high acidity. In the presence of lutidine, a base-dependent and different electrochemical behavior was observed at low scan rates indicating a second oxidation step leading to the corresponding cationic quinone methide precursor (3b(+)). However, compared to ruthenocene derivatives, the stability of 3b(+) prevented its conversion into quinone methide as the final and stable complex. Despite differences in their oxidative processes, osmociphenol and ruthenociphenol derivatives exhibit similar biological activities. (C) 2019 Elsevier Ltd. All rights reserved.