Table of Contents
Metal-Based Drugs
Volume 5 (1998), Issue 2, Pages 91-102

Platinum (II) Compounds With Antitumor Activity Studied by Molecular Mechanics

Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria

Received 5 January 1998; Accepted 13 February 1998

Copyright © 1998 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


A series of Pt(ll) complexes with antitumor properties: [1,2-bis(2,6-dichloro-4-hydroxyphenyl)ethylenediamine]PtL2 (meso-1-PtL2) and [erythro-1-(2,6-dichloro-4-hydroxyphenyl)-2-(2-halo-4-hydroxyphenyl)ethylenediamine]PtL2, [2L=2Cl,2I,SO42; halo = F (erythro-8-PtL2), halo = Cl (erythro-9-PtL2)] has been modelled by molecular mechanics (MM). The MM calculations were carried out for different isomers and ligand conformations meso-δ, meso-λ, d,l-δ, d,I-λ. The compounds with the lowest MM energies have the same geometries as those obtained by X-ray analysis. The calculated MMX energy orders: meso-1-PtL2 < erythro-9-PtL2 < erythro-8-PtL2 for L=I, Cl and SO42 are reverse to the known antitumor activity order - the lowest energy complex (the most stable one)is the one with the highest estrogen activity (meso-1-PtL2). The type of the leaving group (L) does not alter the energy order, which is in agreement with the biological experiments that show a slight dependence of the estrogen properties on the leaving group type.