STUDIES ON THE ANTITUMOR-ACTIVITY OF COMPLEXES OF R2SN(IV) WITH PENICILLAMINE ENANTIOMERS AND WITH 3-THIO-PROPANOIC ACID, AND CORRELATION WITH STRUCTURAL ASPECTS

The activity of diorganotin(IV) derivatives, with Sn-S bonds, against murine leukemia P-388, has been investigated. The water-soluble penicillamine (PenH2) complexes, Me2Sn(D-Pen), Me2Sn(L-Pen), MeSn(D-PenH)2 and Me2Sn(L-PenH)2, are essentially inactive, and do not show any dependence of the antitumor activity from the configuration about the chiral centre. The complexes with 3-thiopropanoic acid (H2Tpr), R2Sn(Tpr), are active for R = Et and Ph, in line with the general behaviour of R2Sn(IV) derivatives. The nature of the organotins in the vehicle of administration is investigated by Sn-119 Mossbauer spectroscopy. The structures of solid state polymers, occurring in suspensions, are discussed. In aqueous phase, the skeleton C2SnS (equatorial, intrigonal bipyramidal species) and C2SnS2 (tetrahedral) are maintained in freshly prepared specimens. The compounds investigated insert into classes R2SnSR' and R2Sn(SR')2, for both antitumor activity and structure, irrespective of the presence, and the eventual configuration, of a chiral centre of an amino acid tail in the ligand.