CYTOTOXICITY OF ASYMMETRIC PLATINUM COMPLEXES AGAINST L-1210 CELLS - EFFECT OF BULKY SUBSTITUENTS

The asymmetric platinum complexes cis-Pt(LL')Cl2 (L = NH3, L’ = CH3NH2, (CH3)2NH, C2H5NH2 and (C2H5)2NH and LL’ = A,A-dimethylethylenediamine), —one of the NH3 groups of c«-Pt(NH3)2Cl2 was substituted by alkylamine—, were synthesized and their cytotoxic effects have been measured using L-1210 cells. The IC50 values of the asymmetric platinum complexes, —being obtained after 24 h exposure of L-1210 cells to the platinum complexes—, are almost comparable to the corresponding value of cis-Pt(NH3)2Cl2. In 2h exposure, however, the IC50 values of the platinum complexes were dramatically changed, i.e., a marked difference was observed between those of L’ = RNH2 and L’ = R2NH. On the other hand, the amounts of platinum taken into the L-1210 cells is little affected by the alkylamino substitution. The results suggest that the bifunctional platinum binding to the target molecule may be responsible for the cytotoxicity. © 1990, The Pharmaceutical Society of Japan. All rights reserved.