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A Kinetic Analysis Of The Conformational Flexibility Of Steroid Hormones, Steven P. Bradbury, Julian Ivanov, Ovanes Mekenyan, Gerritt Schüürmann

Steven P. Bradbury

For a set of 10 androgen steroids and estradiol (E2), the kinetic feasibility of conformation flexibility of the cyclic moieties was studied under the constraint of maintaining the B/C trans and C/D trans ring fusion of the natural and biologically active enantiomer. To this end, the conformational energy surface was quantified using the semiempirical quantum chemical AM1 model. The computational analysis included the location of Conformational transition states with associated barriers, and intrinsic reaction coordinate (IRC) calculations to characterize the trajectories of the rotations and the relationships of the transition states to neighbouring chair and twist conformations. Conformational transformations were …