NMR Study of Conformational Preferences of Inhibitors of Monoamine Uptake

We have used the recently developed tensor decomposition 3D-QSAR method to predict the conformation and alignment of cocaine derivatives bound to the monoamine transporters, NET, DAT and SERT. The analysis revealed that the ligands bind to the receptors in a conformation with the 3β-aryl group orthogonal or approximately orthogonal to the tropane ring. Semi rigid ligands have been prepared with a 3β-aryl group having strong conformational preferences for this orientation. Two compounds had affinities for the DAT and SERT in the low nanomolar range. The solution conformation of one compound has been determined and the results support the results of the 3D-QSAR analysis. Comparisons of affinities and selectivities of these ligands are discussed.