Topological structure activity analysis of diphosphonates in the elimination of radionuclides from body

The effectiveness of a series of diphosphonates in the elimination of radionuclides from rat was analyzed by means of topological structure and activity relations. It is possible to compute some numbers or indexes characteristic of the topological structure of a molecule. The Wiener Index which measures the ramification of a molecule has been chosen. An attempt was made to correlate the effectiveness of the molecules tested in removing plutonium from the organism to their Wiener Index. Only unprotected molecules i.e in free acidic form fitted the correlation. LICAM (C) and DTPA were used as reference molecules to control these results. The fact that LICAM (C) well fitted the relation and that DTPA did not are discussed, as are some general requirements for a new molecule to be effective.