UC-1770

The inhibition of soluble epoxide hydrolase (sEH) has emerged as an attractive therapeutic strategy through the stabilization of endogenous bioactive epoxyeicosatrienoic acids. Most of the inhibitors developed to date contain a central urea pharmacophore; however, these compounds often suffer from physicochemical limitations, particularly limited aqueous solubility. Herein, we report the design, synthesis, and biological evaluation of a new family of 2‐(1‐benzylpiperidin‐4‐yl)acetamides inspired by the reference sEH inhibitor 1‐(1‐propionylpiperidin‐4‐yl)‐3‐(4‐(trifluoromethoxy)phenyl)urea (TPPU). Replacement of the urea pharmacophore in TPPU with an amide significantly improved aqueous solubility but reduced inhibitory potency. Surprisingly, substitution of the trifluoromethyl group of TPPU with a pentafluorosulfanyl substituent restored potency against human sEH, leading to the identification of a promising hit compound. Subsequent structure–activity relationship studies guided by the Topliss Batchwise Scheme (TBS) enabled systematic optimization of the aromatic substitution pattern and revealed that electronic effects are the main drivers of inhibitory potency, leading to several analogs displaying strong activity across human, mouse, and rat sEH. However, their further development was discontinued due to safety‐related liabilities identified during the screening cascade. Nevertheless, these results highlight the utility of the underexplored pentafluorosulfanyl group and the TBS strategy for optimizing amide‐based sEH inhibitors.

The soluble epoxide hydrolase (sEH) is widely studied for its therapeutic potential in inflammation, cardiovascular disease, and pain through stabilization of endogenous epoxyeicosatrienoic acid (EET). Here, we evaluated the impact of several urea-type sEH inhibitors on steroid hormone synthesis; another pathway in which sEH may be involved. Steroidogenesis assays employing the adrenocortical carcinoma cell line H295R demonstrated that TPPU and several other urea-type sEH inhibitors induce dose-dependent suppression of multiple steroid hormones without cytotoxicity, whereas the amide-based GSK2256294A had no effect on steroid production or cell survival. Substrate-to-product ratio analysis suggested selective modulation of CYP17, CYP21, and 17β-hydroxysteroid dehydrogenase activities, with only partial transcriptional changes in select steroidogenic genes. Exogenous 11,12-epoxyeicosatrienoic acid (EET) did not reproduce these effects, and TPPU maintained suppression under dbcAMP stimulation, indicating an off-target mechanism downstream of cAMP signaling. Collectively, these findings reveal that urea-based sEH inhibitors suppress adrenal steroidogenesis via scaffold-dependent, off-target mechanisms independent of sEH. In addition, it suggests that sEH is not involved directly in steroid metabolism.