Developing potential agents against atherosclerosis: Design, synthesis and pharmacological evaluation of novel dual inhibitors of oxidative stress and Squalene Synthase activity

For the treatment of multifactorial and complex diseases, it has become increasingly apparent that compounds acting at multiple targets often deliver superior efficacy compared to compounds with high specificity for only a single target. Based on previous studies demonstrating the important antioxidant and anti-hyperlipidemic effect of morpholine and 1,4-benzo(x/thi)azine derivatives (A-E), we hereby present the design, synthesis and pharmacological evaluation of novel dual-acting molecules as a therapeutic approach for atherosclerosis. Analogues 1–10 were rationally designed through structural modifications of their parent compounds (A-E) in order for structure-activity relationship studies to be carried out. Most compounds showed a significant inhibition against Squalene Synthase activity exhibiting at the same time a very potent multimodal antioxidant (against lipid peroxidation and as free-radical scavengers) effect, thus bringing to light the 2-aryl-1,4-benzo(x/thia)zin-2-ol scaffold as an outstanding pharmacophore for the design of potent antioxidants. Finally, the replacement of the octahydro-1,4-benzoxazine moiety of lead compound D with its respective 1,4-benzothiazine (compound 4), although conserved (anti-hypercholesterolemic) or even improved (anti-hyperlipidemic) activity, did not preserve the anti-diabetic effect of D. [Display omitted] •Synthesis and pharmacological evaluation of new morpholine and 1,4-benzo(x/thi)azine derivatives.•Most compounds significantly inhibited Squalene Synthase activity (IC50 7–28 μΜ).•They exhibited at the same time a very potent multimodal antioxidant profile.•2-aryl-1,4-benzo(x/thia)zin-2-ol is a new pharmacophore for the design of potent antioxidants.•Compound 4 exhibited a significant in vivo hypocholesterolemic and hypolipidemic activity.