Towards β-selectivity in functional estrogen receptor antagonists.

Area of Science:

• Medicinal Chemistry
• Molecular Pharmacology
• Drug Discovery

Background:

• Estrogen receptors (ERs) play critical roles in various physiological processes.
• Selective modulation of ERα and ERβ subtypes is crucial for targeted therapies.
• Benzo[b]naphtho[1,2-d]furan and benzo[b]naphtho[1,2-d]thiophene scaffolds are explored for potential ER activity.

Purpose of the Study:

• To synthesize and evaluate novel ligands based on benzo[b]naphtho[1,2-d]furan and benzo[b]naphtho[1,2-d]thiophene frameworks.
• To investigate the structure-activity relationships and binding modes of these ligands with ERα and ERβ.
• To identify selective ERβ antagonists for potential therapeutic applications and mechanistic studies.

Main Methods:

• Synthesis of ligands incorporating different basic side chains (BSCs).
• In vitro competitive binding assays to determine receptor affinity.
• Cell-based luciferase reporter assays to assess functional antagonism.
• Molecular docking techniques to model ligand-receptor interactions.

Main Results:

• Introduction of BSCs generally decreased affinity for both ERα and ERβ.
• Two compounds (9c and 9f) emerged as potent, low micromolar ERβ antagonists.
• Compounds 9c and 9f showed no activity against ERα at the tested concentrations.
• Molecular modeling provided insights into differential binding modes between ERα and ERβ.

Conclusions:

• Novel benzo[b]naphtho[1,2-d]furan/thiophene derivatives were synthesized and characterized.
• Selective ERβ antagonists (9c and 9f) were discovered with potential for elucidating ER subtype-specific roles.
• The identified ligands offer a promising chemical platform for developing subtype-selective ER modulators.