Metal chelates as anti-cancer agents. II cytotoxic action of palladium and platinum complexes of 6-mercaptopurine and thioguanine

M Das,S E Livingstone

doi:10.1038/bjc.1978.205

Abstract

The metal complexes Pd(MP)2.2H2O, Pt(MP)2H2O (MPH=6-mercaptopurine), Pt(AMP2.3H2O and Pd3(AMP)4Cl2(AMPH).4H2O (AMPH=thioguanine) have been isolated. They were screened for anti-tumour activity in the L-1210 lymphoid leukaemia test system in mice. All 4 show marked anti-tumour activity, the complex Pt(AMP)2.3H2O giving a T/C of 185 at the optimum dosage. However, the anti-tumour activity of the metal complexes is somewhat less than that shown by the parent purines under the same conditions.

Highlights

As part of our study of metal chelates* as potential anticancer agents, we have prepared palladium (Pd) and platinum (Pt) complexes of these purines and had them screened in the LI 210 lymphoid leukaemia test system
The cis configuration is favoured relative to the trans configuration for transition metal complexes of thiolo ligands (Das et al, 1974)
If meaningful comparisons are to be made for the relative anti-tumour activities of the purines and their metal chelates, the screening must be done under the same conditions

Summary

Introduction

They were screened for anti-tumour activity in the L-1210 lymphoid leukaemia test system in mice. All 4 show marked anti-tumour activity, the complex Pt(AMP)2 *3H20 giving a T/C of 185 at the optimum dosage. The anti-tumour activity of the metal complexes is somewhat less than that shown by the parent purines under the same conditions. As part of our study of metal chelates* as potential anticancer agents, we have prepared palladium (Pd) and platinum (Pt) complexes of these purines and had them screened in the LI 210 lymphoid leukaemia test system. 29% at the optimum dosage in the Sarcoma 180 test system in mice but showed no significant activity in the Adenocarcinoma 755 test system. The formation constants of the nickel (II), cobalt(II), lead(II), and zinc(II) complexes of 6-mercaptopurine were determined by Cheney et al (1959) and the isolation of the metal complexes Met(MP) n-

Methods

Results

Conclusion