Insertion of (Bioactive) Equatorial Ligands into Platinum(IV) Complexes

Area of Science:

• Medicinal Chemistry
• Oncology
• Inorganic Chemistry

Background:

• Platinum(IV) prodrugs offer advantages over platinum(II) drugs, including enhanced tumor selectivity and fewer side effects.
• Established theories on platinum(IV) complex reactivity have been challenged by recent observations of equatorial ligand hydrolysis.

Purpose of the Study:

• To investigate the reactivity and synthetic utility of hydrolyzed platinum(IV) complexes as precursors for novel platinum(IV) drug development.
• To synthesize and evaluate platinum(IV) complexes with unique equatorial ligand substitutions for improved anticancer strategies.

Main Methods:

• Hydrolysis of oxaliplatin(IV) to form a precursor complex.
• Substitution of equatorial hydroxido ligands with biotin and maleimide moieties.
• In vivo evaluation of platinum(IV) complexes for plasma half-life and anticancer activity.

Main Results:

• Successfully synthesized novel platinum(IV) complexes by substituting equatorial hydroxido ligands.
• Developed stable platinum(IV) complexes with slow ligand release, suitable for long-circulating tumor targeting.
• Synthesized platinum(IV) complexes with equatorial maleimides demonstrated prolonged plasma half-life and superior in vivo anticancer activity compared to oxaliplatin.

Conclusions:

• A new synthetic platform enables straightforward and specific equatorial ligand insertion into platinum(IV) complexes.
• This platform facilitates the creation of targeted, triple-action platinum(IV) prodrugs by attaching multiple bioactive moieties.
• The developed platinum(IV) complexes show significant potential for advanced cancer therapeutics with improved efficacy and targeting.