Desulfurization of thiosemicarbazones: the role of metal ions and biological implications

Are the metal identity and stoichiometry of metal complexes important for colchicine site binding and inhibition of tubulin polymerization?

“…The decrease of the absorbance band at 310 nm is most likely due to the acid-catalyzed cleavage of the CN Schiff base bond, resulting in a less extended conjugation system in the molecule or desulfurization, which is likely under acidic conditions. 45,46 The much more extensive hydrolysis of TSCs with a methyl group at the azomethine carbon was reported previously for 2-acetylpyridine TSCs. 47 Spectral changes observed at pH 11.7 are likely due to Schiff base hydrolysis as well, although, in the case proligands containing the redox-active 2,6-dimethylphenol group ( HL 1 and HL 2 ), oxidation may also occur, as was reported for triapine analogues.…”