A comparative chemical-biological evaluation of titanium(IV) complexes with a salan or cyclopentadienyl ligand.

Titanium(IV) complexes with a salan or cyclopentadienyl ligand showed different biological behaviour concerning binding to biomolecules, cellular accumulation and intracellular distribution. Binding efficacy as well as trafficking on the cellular level are crucial parameters for their biological effects.

Alterations of phosphoproteins in NCI-H526 small cell lung cancer cells involved in cytotoxicity of cisplatin and titanocene Y.

First-line treatment of small cell lung cancer (SCLC) with combination chemotherapy consisting of cis-diamminedichloroplatinum(II) (cisplatin) and etoposide is frequently followed by early relapses and a dismal prognosis. Survival of a fraction of tumor cells and development of chemoresistance may be influenced by an initial cellular stress response against the administered xenobiotics. Therefore, we compared the short-term effects of cisplatin and non-cross-resistant bis-[(p-methoxybenzyl)cyclopentadienyl] titanium(IV) dichloride (Titanocene Y) on phosphorylation of 46 sites of a total of 38 signaling proteins in tumor suppressor protein 53 (p53)-wild-type NCI-H526 SCLC cells.

Synthesis and biological evaluation of achiral indole-substituted titanocene dichloride derivatives.

Six new titanocene compounds have been isolated and characterised. These compounds were synthesised from their fulvene precursors using Super Hydride (LiBEt3H) followed by transmetallation with titanium tetrachloride to yield the corresponding titanocene dichloride derivatives. These complexes are bis-[((1-methyl-3-diethylaminomethyl)indol-2-yl)methylcyclopentadienyl] titanium (IV) dichloride (5a), bis-[((5-methoxy-1-methyl,3-diethylaminomethyl)indol-2-yl)methylcyclopentadienyl] titanium (IV) dichloride (5b), bis-[((1-methyl,3-diethylaminomethyl)indol-4-yl)methylcyclopentadienyl] titanium (IV) dichloride (5c), bis-[((5-bromo-1-methyl)indol-3-yl)methylcyclopentadienyl] titanium (IV) dichloride (5d), bis-[((5-chloro-1-methyl)indol-3-yl)methylcyclopentadienyl] titanium (IV) dichloride (5e), and bis-[((5-fluoro-1-methyl)indol-3-yl)methylcyclopentadienyl] titanium (IV) dichloride (5f).

Novel benzyl-substituted N-heterocyclic carbene-silver acetate complexes: synthesis, cytotoxicity and antibacterial studies.

From the reaction of 1-methylimidazole (1a), 4,5-dichloro-1H-imidazole (1b(I)) and 1-methylbenzimidazole (1c) with p-cyanobenzyl bromide (2a), non-symmetrically substituted N-heterocyclic carbene (NHC) [(3a-c)] precursors, 5,6-dimethyl-1H-benzimidazole (1d) and 4,5-diphenyl-1H-imidazole (1e) with p-cyanobenzyl bromide (2a) and benzyl bromide (2b), symmetrically substituted N-heterocyclic carbene (NHC) [(3d-f)] precursors were synthesised. These NHC-precursors were then reacted with silver(i) acetate to yield the NHC-silver complexes (1-methyl-3-(4-cyanobenzyl)imidazole-2-ylidene)silver(i)acetate (4a), (4,5-dichloro-1-(4-cyanobenzyl)-3-methyl)imidazole-2-ylidene)silver(i)acetate (4b), (1-methyl-3-(4-cyanobenzyl)benzimidazole-2-ylidene)silver(i)acetate (4c), (1,3-bis(4-cyanobenzyl)5,6-dimethylbenzimidazole-2-ylidene) silver(i) acetate (4d), (1,3-dibenzyl-5,6-dimethylbenzimidazole-2-ylidene) silver(i) acetate (4e) and (1,3-dibenzyl-4,5-diphenylimidazol-2-ylidene) silver(i) acetate (4f) respectively. Three NHC-precursors 3c-e and four NHC-silver complexes 4b and 4d-f were characterised by single crystal X-ray diffraction.

Pseudo-halide derivatives of titanocene: synthesis and cytotoxicity studies.

The well-known anticancer drug candidate bis-[(p-methoxybenzyl)cyclopentadienyl] titanium(IV) dichloride (Titanocene ) was reacted with sodium azide or potassium cyanate, thiocyanate or selenocyanate in order to give pseudo-halide analogues of Titanocene . and were characterised by single crystal X-ray diffraction, which confirmed the expected nitrogen binding of the cyanate and thiocyanate to the titanium centre. All four titanocenes had their cytotoxicity investigated through preliminary in vitro testing on the LLC-PK (pig kidney epithelial) cell line in an MTT based assay in order to determine their IC50 values.