An overview of the development of antitumour organotin derivatives is presented and discussed for selected classes of compounds, such as tetraorganodicarboxylatodistannoxanes and related diorganotin dicarboxylates, and for triorganotin carboxylates. Among the carboxylate groups used are steroidcarboxylates and other biologically relevant carboxylates. High to very high in vitro activities have been found, sometimes equalling that of doxorubicin. Solubility in water is an important issue, dominating the in vivo testing of compounds. Polar substituents, like fluorine or polyoxaalkyl moieties, improve the water solubility. Although organotin derivatives constitute a separate class of compounds, the comparison with cisplatin is inevitable. Among the observed toxicities, neurotoxicity, known from platinum cytostatics, and gastrointestinal toxicity, typical for many oncology drugs, have been detected, but to a lower extent. Further research to develop novel useful organotin antitumour compounds needs to be carried out.

We have been active in the synthesis and characterization of tin-based antitumour compounds for several years and we would like to summarize here the results that have already been patented(1) and that may therefore be disclosed(2). We synthesized some diorganotin 2,6-pyridinedicarboxylates.The dimethyltin compound has been found inactive in vitro, whereas the din -butyltin, di-t-butyltin and diphenyltin compounds were found more active than cisplatin(2).

The original article to which these Errata refer was published in the journal Applied Organometallic Chemistry 2003; 17(5): 305–314. Copyright © 2003 John Wiley & Sons, Ltd.

A series of R 3 SnO 2 CR′ compounds, where R) Me (1), Et (2), n Bu (3), Ph (4), and cHex (5) and R′CO 2 is the carboxylate residue of 2-[(E)-2-(2-hydroxy-5-methylphenyl)-1-diazenyl]benzoic acid, has been shown by multinuclear magnetic resonance studies to be monomeric in solution. Crystallography shows that monomeric four-coordinate species are found in the solid state for 4 and 5 but polymeric structures with five-coordinate tin atoms are found for 1-3. The different behavior is ascribed to the steric demands of the tin-bound substituents. A fair correlation is found between the difference in 117 Sn chemical shift between the solution and solid states and the carbonyl oxygen-tin distance of the compounds 1-5, only when the data of 4, R) Ph, are omitted. This indicates that the mesomeric effect of the phenyl group does not express its influence to the same extent in the solid and solution states, unlike the inductive effects. By contrast, a good correlation including 4 is found between the Mössbauer quadrupole splitting and the difference in 117 Sn chemical shift between the solution and solid states. This shows that the nature of the organic group on the tin atom contributes to similar extents to the values of the 117 Sn chemical shifts in solution and solid state, independently of the existence or not of mesomeric effects, and that the parallel behavior of QS and 117 Sn chemical shifts is geometry independent.