STUDY OF QSAR FOR ~(153)Sm COMPLEXES AS BONE SEEKING AGENT

The molecular modeling software, Material Studio 2.0, is employed to build the molecular models for the 17 153Smlabelled boneseeking radiopharmaceuticals. Their structures are first optimized with molecular mechanics and then the predominant conformations are found by using molecular dynamics. Energies of the 17 ligands in aqueous solution are calculated by the semiempirical orbital computation software package Vamp. A series of microscopic parameters such as LUMO and HOMO energies, delocalization energies and heat of formation are obtained. By choosing ADME violation number x10, surface area x14, and HOMO energy x20 as descriptors, a satisfactory QSAR equation is found by using QSAR analysis software TsarTM3.3 for bone uptake(BU/(%·g-1))2 h post injection. The equation is BU=-29.39/x10+12 455/x14-790.9/x20-82.38 with n=15, r=0.960 0, s=5.020, F=0, r2(CV)=0.590 4.