Ab initio Calculation of the Electronic Structure and Equilibrium Geometry of Cortisol and Its Derivatives

The molecular geometries of a series of steroid hormones including cortisol, 9-fluorocortisol, 6-fluorocortisol, and 9-chlorocortisol were optimized by 3-21G and 6-31G* ab initio calculations. The results of calculations on both levels are well consistent with each other and with the experiment. The conformational changes and electron density redistribution occurring in going from cortisol to its 6- and 9-halo derivatives were discussed. A conclusion was made that the O and F atoms can participate in hydrogen bonding with the corresponding structural groups of glucocorticoid receptors.     

Quantum-Chemical Study of the Equilibrium Geometry and Electronic Structure of the Defensin Molecule

The molecular geometry of rabbit NP-1 defensin is fully optimized by means of molecular mechanics and MNDO methods. Atomic charges are calculated, and an estimate for the dipole moment of the molecule is obtained ( 4.0 D). The possible mechanism of defensin-receptor interactions is discussed.