X-RAY STUDIES, EMPIRICAL, SEMIEMPIRICAL AND STATISTICAL CALCULATIONS ON A SERIES OF THYROTROPIN-RELEASING-HORMONE DERIVATIVES

The crystal structure of two thyrotropin-releasing hormone (TRH) deriv atives has been determined and used with previous X-ray structures of other analogs as the starting set for in vacuo semi-empirical and empi rical calculations, in order to evaluate the conformational freedom of these compounds. Data collected from the dynamics calculations have b een used for attempting a classification of the preferred arrangements by means of a statistical analysis software package. Consensus dynami cs calculations have also been performed to extrapolate a pharmacophor e model.