Antitumour Organometallics. III. In Vivo Activity of Diphenylantimony(III) and Diorganotin(IV) Dithiophosphorus Derivatives Against P388 Leukemia

Diphenylantimony(III) and diorganotin(IV) derivatives of dithiophosphorus ligands, i.e. Ph(2)SbS(2)PR'(2) (R' = Ph, OPr-i) and R(2)Sn(S(2)PR'(2))(2) (R = n-Bu, Ph, R' = Ph; R = Ph, R' = OPr-i), have been screened against P388 leukemia in mice. All the compounds showed marginal activity towards this tumor system, some of them increasing the life span of the animals with more than 20%. The best results were obtained with (di-iso-propylphosphorodithioato)diphenylantimony(III) which exhibited a T/C value of 136%, at a dose of 5 mg/kg, administered on days 1,2 and 3 after tumor transplantation.