A new consistent model explaining structure (conformation)-activity relationships of opiates with mu-selectivity

Area of Science:

• Pharmacology
• Computational Chemistry
• Molecular Modeling

Background:

• Opiates represent a diverse class of compounds with varying potencies and activities.
• Understanding the molecular interactions between opiates and their receptors is crucial for drug development.
• Existing models may not fully explain the structure-activity relationships across different opiate classes.

Purpose of the Study:

• To develop a new model for mu-selective opiate conformation-activity relationships.
• To elucidate the binding orientations and receptor interactions of various opiates.
• To provide a unified explanation for the diverse activities of examined opiate compounds.

Main Methods:

• Utilized the SYBYL molecular modeling program package and the TRIPOS empirical force field.
• Performed energetic optimization of various opiate structures, including PET, phenazocine, fentanyl, carfentanil, ohmefentanyl, prodine derivatives, methadone, and etonitazene.
• Analyzed molecular electrostatic potentials and identified six key spatial positions for receptor interaction.

Main Results:

• A novel model for mu-selective opiate conformation-activity relationships was developed.
• Identified two distinct binding orientations for the protonated nitrogen atom of opiates interacting with the receptor.
• The model successfully explains the diverse activities of the examined opiates in a unified manner.
• Predicted the most active stereoisomer of ohmefentanyl based on the proposed model.

Conclusions:

• The developed model offers new insights into critical opiate-receptor interactions.
• The findings provide a unified framework for understanding the activity of various mu-selective opiates.
• This research facilitates the design of novel analgesics with improved efficacy and selectivity.