Discovery of Novel Ortho-Aminophenol Derivatives Targeting Lipid Peroxidation with Potent Antiferroptotic Activities.

The concept of ferroptosis inhibition has gained growing recognition as a promising therapeutic strategy for addressing a wide range of diseases. Here, we present the discovery of four series of ortho-aminophenol derivatives as potential ferroptosis inhibitors beginning with the endogenous substance 3-hydroxyanthranilic acid (3-HA) by employing quantum chemistry techniques, in vitro and in vivo assays. Our findings reveal that these ortho-aminophenol derivatives exhibit unique intra-H bond interactions, compelling ortho-amines to achieve enhanced alignment with the aromatic π-system, thereby expanding their activity. Notably, compounds from all four series display remarkable activity against RSL3-induced ferroptosis, showcasing an activity 100 times more than that of 3-HA. Furthermore, these compounds also demonstrate robust in vivo efficacy in protecting mice from kidney ischemia-reperfusion injury and acetaminophen-induced hepatotoxicity. In summary, we provide four distinct series of active scaffolds that significantly expand the chemical space of ferroptosis inhibitors, serving as valuable insights for future structural modifications.

Design, synthesis, and biological evaluation of 2-amino-6-methyl-phenol derivatives targeting lipid peroxidation with potent anti-ferroptotic activities.

The suppression of ferroptosis is emerging as a promising therapeutic strategy for effectively treating a wide range of diseases, including neurodegenerative disorders, organ ischemia-reperfusion injury, and inflammatory conditions. However, the clinical utility of ferroptosis inhibitors is significantly impeded by the limited availability of rational drug designs. In our previous study, we successfully unraveled the efficacy of ferrostatin-1 (Fer-1) attributed to the synergistic effect of its ortho-diamine (-NH) moiety. In this study, we present the discovery of the ortho-hydroxyl-amino moiety as a novel scaffold for ferroptosis inhibitors, employing quantum chemistry as well as in vitro and in vivo assays. 2-amino-6-methylphenol derivatives demonstrated remarkable inhibition of RSL3-induced ferroptosis, exhibiting EC50 values ranging from 25 nM to 207 nM. These compounds do not appear to modulate iron homeostasis or lipid reactive oxygen species (ROS) generation pathways. Nevertheless, they effectively prevent the accumulation of lipid peroxides in living cells. Furthermore, compound 13 exhibits good in vivo activities as it effectively protect mice from kidney ischemia-reperfusion injury. In summary, compound 13 has been identified as a potent ferroptosis inhibitor, warranting further investigation as a promising lead compound.

Structural Change and Radical Generation of a Cadmium-Based Metal-Organic Framework Induced by an Electric Field.

Herein we report the structural change and radical generation of a cadmium-based metal-organic framework (Cd-MOF) induced by external electric fields. Under a weaker single electric field, different coordination modes of Cd-L lead to 3D → 2D structural change. Under stronger superposed electric fields, Cd-MOF was excited to produce a stable free radical. This study will provide a new avenue for the controlled assembly of MOFs.