Computational Study on Molecular Orbital's, Excited State Properties and Geometry Optimization of Anti-benign Prostatic Hyperplasia Drug, N-(1,1-dimethylethyl)-3-oxo-(5α,17β)-4-azaandrost-1-ene-17-carboxamide (Finasteride)

Finasteride, N-(1,1-dimethylethyl)-3-oxo-(5α, 17β)-4-azaandrost-1-ene-17-carboxamide is a synthetic drug for the treatment of benign prostatic hyperplasia (BPH) and male pattern baldness (MPB). The electronic excited-state calculations were carried out by ZINDO semi-empirical method using ArgusLab 4.0.1 software. Conformational analysis (geometry optimization) of finasteride was carried out using PM3 semi-empirical QM parameterization according to Hartree-Fock calculation method by ArgusLab 4.0.1 software. All the results obtained from molecular orbital's, electronic excited state properties and electrostatic potential map suggested the active charged groups in the molecule where interaction with the receptor 5α – reductase is probable. The geometry convergence map of finasteride clearly showed a decrease in potential energy with the progress of rotation. The minimum potential energy was calculated to be -100315.73 kcal/mol (−159.86 au). The best conformation of finasteride was found to be 100315.73 kcal/mol which is the minimum potential energy calculated by geometry convergence function using ArgusLab software; performed according to Hartree-Fock calculation method. The most feasible position for finasteride to inhibit the receptor 5α – reductase was found to be -100315.73 kcal/mol.