Blocking oestradiol synthesis pathways with potent and selective coumarin derivatives

Area of Science:

• Medicinal Chemistry
• Endocrinology
• Drug Discovery

Background:

• Oestradiol synthesis is crucial in hormone-dependent diseases like breast cancer and endometriosis.
• The sulphatase pathway and aromatase pathway are key regulators of oestradiol levels.
• Targeting these pathways offers therapeutic strategies for hormone-related conditions.

Purpose of the Study:

• To synthesize and evaluate 3-phenylcoumarin analogues as inhibitors of 17-beta-hydroxysteroid dehydrogenase 1 (HSD1).
• To explore structure-activity relationships for HSD1 inhibition and cross-reactivity.
• To identify novel inhibitors for the sulphatase and aromatase pathways.

Main Methods:

• Synthesis of 3-phenylcoumarin analogues with polar substituents.
• Enzyme inhibition assays for HSD1.
• Docking-based structure-activity relationship analysis.
• Cross-reactivity testing against related enzymes (oestrogen receptor, aromatase, CYP1A2, MAOs).

Main Results:

• Five analogues demonstrated significant HSD1 inhibition (≥62% at 5 µM).
• Three analogues showed potent HSD1 inhibition (≥68% at 1 µM).
• Identified 3-imidazolecoumarin as a potent aromatase inhibitor.
• Most analogues had modest activity against 17-beta-hydroxysteroid dehydrogenase 2.

Conclusions:

• The coumarin scaffold can be modified to selectively inhibit key enzymes in oestradiol synthesis.
• Targeted inhibition of HSD1 and aromatase offers a dual approach for treating breast cancer and endometriosis.
• Developed compounds show promise for therapeutic intervention in hormone-dependent diseases.