New butyltin complexes with
2-sulfobenzoic acid: [Sn(C4H9)2{O3SC6H4COO-2}(H2O)]·(C2H5OH) (DBTsbz), [Sn(C4H9)3{O3SC6H4COOH-2}] (TBTsbz) and [Sn2(C4H9)6{μ-O3SC6H4COO-2}] (DTBTsbz) are very effective
cytotoxic agents against
tumor cells. The molecular interaction of these complexes with
lipid membranes and
DNA has been investigated. The IR spectra and changes of (1)H, (13)C chemical shifts suggest that SO3 and
COO groups of 2-sulfobenzoato
ligand interact with O atom of
glycerin fragment of DPPC. Moreover, the compounds form Sn-OP bonds with
phosphate groups of DPPC, which was shown by the lower frequency shift of the νs(PO2(-)) and νas(PO2(-)) band, by change of (31)P NMR signals and by DFT calculation. Another possibility is the interaction of the
phosphate group of DPPC owing to formation of hydrogen bond O-H…O-P between water molecule coordinated to Sn and
oxygen atom from the
phosphate group. Using TCSPC-FCS we characterized
DNA supramolecular assemblies' formation upon increasing TBTsbz, DTBTsbz and DBTsbz concentration. Diffusion time, lifetime and particle number changes are altered systematically with increasing Ccomp/CDNAbp ratio in following effectiveness order DBTsbz > TBTsbz > DTBTsbz. From those parameters we can conclude that all these compounds lead to a change of
DNA winding, strand but not to
DNA compaction. Investigated compounds show very high cytotoxic activity against
cancer cell lines. All compounds exhibit efficient in vitro antitumor activity toward Jurkat (
T-cell leukemia), CL-1 (T-lymphoblastoid cell line), GL-1 (
B cell lymphoma cell line) and D-17 (canine
osteosarcoma). The DBTsbz is more effective then
carboplatin against canine
osteosarcoma.