Abstract

Angiotensin-Converting Enzyme (ACE) plays a pivotal role in the renin–angiotensin system, modulating blood pressure and electrolyte homeostasis by deactivating bradykinin and activating angiotensin II. Metabolites from Senecio nutans (1 and 3), a plant indigenous to the Andean region of the Atacama Desert, and their respective oximes, 2 and 4, were subjected to molecular docking analysis, employing six ACE crystal structures. ACE activity assays revealed that oximes exhibited superior inhibitory effects compared to metabolites. Among the compounds investigated, 2 emerged as the most potent ACE inhibitor (2 = 11.5 ?M and 4 = 13.4 ?M). The vascular contractile response to Angiotensin I showed significant (p < 0.05) reductions in Ang I contraction with 2, 3, and 4 (97 ± 6%, 81 ± 6%, 81 ± 3% compared to control), while 1 exhibited no such effect. These results reinforce the potential of 2 as a promising ACE inhibitor and highlight its impact on vascular contractility. As such, it is a promising candidate for ACE inhibition and hypertension treatment. © 2025 by the authors.