Structure-based Molecular Hybridization Design Of Keap1-Nrf2 Inhibitors As Novel Protective Agents Of Acute Lung Injury

Nuclear factor-erythroid 2 related factor 2（Nrf2）was dissociated from Kelch-like epichlorohydrin-related protein 1（Keap1）in the cytoplasm and penetrated into the nucleus to bind antioxidant response elements（ARE）to resist internal and external harmful substances when stimulated by reactive oxygen or active nitrogen.The Keap1-Nrf2 ARE signaling pathway was closely associated with a variety of diseases,such as diabetes,cancer,Alzheimer’s disease,and acute lung injury（ALI）.In recent years,more and more studies have shown that Nrf2 is an important target for the treatment of ALI.Therefore,the discovery of Keap1-Nrf2 inhibitors was of great significance for the treatment of acute lung injury.This thesis mainly carried out the design,synthesis and anti-acute lung injury research of naphthalenesulfonamide-isothiocyanate derivatives.The specific content includes the following two parts.The first part:NXPZ-2,a naphthalensulfonamide derivative,was previously reported to effectively inhibit the Keap1-Nrf2 PPI by our group.In the present work,a series of novel isothiocyanate-containing naphthalensulfonamides were designed by a structure-based molecular hybridization strategy.Three series of twenty-two naphthalenesulfonamide-isothiocyanate derivatives were obtained through 10 steps of substitution reaction,reduction reaction,coupling and addition reaction.The second part:Among these derivatives,using the fluorescence polarization experiment,we found that they generally have good Keap1-Nrf2 PPI inhibitory activity and low cytotoxicity.The molecular docking software explained that the activity of sulfoxide is better than that of thioether and sulfone sulfonamide-isothiocyanate derivatives.Compounds NXPZ-2,SCN-16,10a and 11 with good in vitro Keap1-Nrf2 inhibitory activity(K_D2<1μM)together with the Nrf2 activator of SFN were selected to evaluate their anti-inflammatory activity in LPS-induced mouse peritoneal macrophages.These compounds could significantly suppress the productions of ROS and NO and the expression of pro-inflammatory cytokine TNF-α,among which sulfoxide SCN-16 had the best activity.Meanwhile,SCN-16 could significantly trigger Nrf2 nuclear translocation which was much apparently than the parent compound NXPZ-2.Our results suggested SCN-16 could be a novel lead compound targeting Keap1-Nrf2 protective pathway for clinical treatment of ALI.