New mononuclear diorganotin(IV) dithiocarboxylates: synthesis, characterization and study of their cytotoxic activities

Anti-proliferative and antitumor activity of organotin(IV) compounds. An overview of the last decade and future perspectives

Organotins(IV) exhibit significant in vitro anti-proliferative activity, while the in vivo tests are encouraging. The recent reports on the anti-proliferative activity of organotin(IV) compounds are summarized in this review. The period covered by this work goes back to 2009 until late 2018, while the earlier ones, are included over the previous review of our group published by S.K. Hadjikakou, N. Hadjiliadis, in Coord Chem Rev, 253 (2009) 235-249. During the last decade (2009-2018), >300 organotin(IV) derivatives with oxygen-donor ligands, such as carboxylic acids, amino-acids, Non Steroidal Anti-inflammatory Drugs (NSAIDs), biological active derivatives or natural products, organotins(IV) with sulfur containing ligands such as thiones, thiosemicarbazones, dithiocarbamates, organotin(IV) compounds of oximes and organotins(IV) with amines or semicarbazones were screened for their anti-proliferative effect against various cancer cell lines and their results are included in numerous reports over this period. Although much work has been carried out on organotin(IV) derivatives with O-donor ligands, however significant fewer reports are found on organotins(IV) with oximes as ligands.

Anti-proliferative activity and DNA/BSA interactions of five mono- or di-organotin(iv) compounds derived from 2-hydroxy-N′-[(2-hydroxy-3-methoxyphenyl)methylidene]-benzohydrazone

Five hydrazone Schiff base organotin(iv) complexes were synthesized and their anticancer mechanism was preliminarily studied.

Organotin(IV) complexes derived from Schiff base N'-[(1E)-(2-hydroxy-3-methoxyphenyl)methylidene]pyridine-4-carbohydrazone: synthesis, in vitro cytotoxicities and DNA/BSA interaction

Five organotin(IV) compounds were synthesized from N'-[(1E)-(2-hydroxy-3-methoxyphenyl)methylidene]pyridine-4-carbohydrazone and the corresponding dialkyltin(IV) or trialkyltin(IV) precursor. Solid state structures were determined by IR, elemental analysis, NMR spectroscopy, and for 1, 2, 4 and 5 single crystal X-ray diffraction analysis. Compounds 1, 2 and 4 are monomers with the tin atoms five-coordinated in distorted trigonal bipyramid, of which the deprotonated Schiff base ligand chelate to tin center in the enolic tridentate mode. Differently, in compound 5, the enolization does not occur for the Schiff base ligand, and only the pyridinyl N atom and the deprotonated phenol hydroxyl oxygen atom participate in the coordination. Fascinatingly, six trimethyltin(IV) coordination units are linked by the Sn⋯N weak interaction atoms and form a 72-membered crown-like macrocycle. Preliminary in vitro cytotoxicity studies on five human tumor cells lines (HL-60, A549, HT-29, HCT-116 and Caco-2) by MTT assay reveal that di-n-butyltin(IV) complex 2 and diphenyltin(IV) complex 4 triggered significant antiproliferative effects in cultured tumor cells, and their cytotoxic activity correlates with intracellular organotin(IV) concentration. The interaction of the complexes with calf thymus DNA (CT-DNA) has been explored by absorption and emission titration methods, which revealed that complexes 2 and 4 interact with CT-DNA through groove-binding and partial intercalation of the extended planar ligand with the DNA base stack. Further, the albumin interactions of complexes 2 and 4 were investigated using fluorescence quenching spectra and synchronous fluorescence spectra. Studies reveal that di-n-butyltin(IV) complex 2 with higher cytotoxicity show stronger DNA/BSA interaction than diphenyltin(IV) complex 4.