Synthesis and preliminary evaluation of a modified estradiol-core bearing a fused γ-lactone as non-estrogenic inhibitor of 17β-hydroxysteroid dehydrogenase type 1

A non-estrogenic inhibitor of 17β-hydroxysteroid dehydrogenase type 1 (17β-HSD1) was designed based on a modified 3-hydroxy-estra-1,3,5(10)-triene core having an additional five-member lactone ring and a benzamide group. The inhibitor was synthesized, fully characterized and tested for its ability to inhibit the enzyme activity. Estrogenicity was also investigated and tested on estrogen-dependent T-47D cell line. Interestingly, this steroid derivative showed inhibitory potency towards 17β-HSD1 and did not present residual unwanted estrogenic activity.