Cancer inflicts a tremendous burden on modern society, and more effective and selective treatments need to be developed. Metallodrugs have been extensively explored as alternatives to current chemotherapeutic regimens that suffer from shortcomings such as severe side effects and acquired resistance. Hydrazide-hydrazones are a family of organic molecules containing the hydrazone functionality attached to a carbonyl group (−C=N−NH−CO). These molecules are extremely versatile and can be obtained from modular reactions between hydrazides and aldehydes or ketones, of which a large library is commercially available. Hydrazide-hydrazones show numerous therapeutic effects, and typically, their metal complexes exhibit increased potency. This review aims to highlight the potential of hydrazide-hydrazone metal complexes in the field of anticancer research. It focuses on the literature published in the last 10 years (2013-2023) and describes their biological effects, their antiproliferative activity and their mechanisms of action. It is organized by metal ion, including Cu, Ru, Pt, Pd, V, other d-block, lanthanide, and Ga and Sn ions. It highlights the diversity of molecules being developed and can be used as a guide for developing new hydrazide–hydrazones as efficient anticancer agents.

[VO(acac)₂] is a remarkable vanadium compound and has potential as a therapeutic drug. It is important to clarify how it is transported in blood, but the reports addressing its binding to serum proteins have been contradictory. We use several spectroscopic and mass spectrometric techniques (ESI and MALDI‐TOF), small‐angle X‐ray scattering and size exclusion chromatography (SEC) to characterize solutions containing [VO(acac)₂] and either human serum apotransferrin (apoHTF) or albumin (HSA). DFT and modeling protein calculations are carried out to disclose the type of binding to apoHTF. The measured circular dichroism spectra, SEC and MALDI‐TOF data clearly prove that at least two VO–acac moieties may bind to apoHTF, most probably forming [V^IVO(acac)(apoHTF)] complexes with residues of the HTF binding sites. No indication of binding of [VO(acac)₂] to HSA is obtained. We conclude that V^IVO–acac species may be transported in blood by transferrin. At very low complex concentrations speciation calculations suggest that [(VO)(apoHTF)] species form.

New Cu ^II - and V ^IV O amino acid complexes show antiproliferative activity mediated by apoptosis and genomic damage.

Solid state and solution studies of trinuclear V^IVO- and V^VO₂-complexes and their peroxidase mimicking activity, through oxidation of dopamine to aminochrome, are reported.