How to identify promising metal scavengers? d-penicillamine with copper as a study case

Therapeutic chelating agents are used to prevent the effects of the metal accumulation. These are molecules that form complexes with transition metals and they are referred here as metal scavengers. The main idea of this investigation is to recognize the most relevant chemical features to identify potential metal scavengers. d-penicillamine with copper (DPEN-Cu) is used for this purpose. The first requirement that must be fulfilled by a good metal scavenger is the exergonicity of the chelating reaction. In the DPEN-Cu case the most likely complexation pathway was found to have G equal to -24.3 kcal/mol. It is desirable that the chelating molecule could also be a free radical scavenger. d-penicillamine is a good free radical scavenger following the hydrogen atom transfer reaction. An additional advantage is that the DPEN-Cu may act as center dot OH-inactivating ligand. It is proposed that chelating agents fulfilling these requirements may be a promising candidate to be used in metal chelation therapies as metal scavengers.