THE EFFECT OF SOLVENT AND CONFORMATIONAL CHANGES ON THE ELECTRON DENSITY AND ELECTROSTATIC POTENTIAL OF TAMOXIFEN [p-(DIMETHYLAMINO-2 ETHOXY)PHENYL]-1 TRANS-DIPHENYL-1,2 BUTENE-1. Dan A. Buzatu, and Edwin D. Stevens, Dept. of Chemistry, University of New Orleans.

The goal of the study was to investigate the effect of conformational changes and solvent on the electron density and electrostatic properties of the antitumor drug Tamoxifen. The different geometries were obtained by doing a molecular dynamics simulation using water as the solvent in C.H.A.R.M.M. The density and electrostatic potential surface for each conformation was calculated from experimental multipole model densities by assuming that the multipoles coordinate systems follow the changes in the atomic positions, and their populations remain unchanged. The X-ray data was collected using Mo K[[alpha]] radiation at 100 K. These results were then compared with densities and electrostatic potential surfaces obtained from ab initio calculations at the 6-31G* level for the same conformations. The ultimate aim of this work is to simulate the behavior of a drug in blood.