RESUMO
A total synthesis of kopsone was achieved, featuring stereoselective preparation of an acyclic aldehyde having a protected hydroxylamine moiety via Ireland-Claisen rearrangement and intramolecular cycloaddition of an eight-membered cyclic nitrone to form the 2-azabicyclo[3.3.1]nonane skeleton.
RESUMO
Acrolein (ACR) is a metabolic byproduct in vivo and a ubiquitous environmental toxicant. It is implicated in the initiation and development of many diseases through multiple mechanisms, including the induction of oxidative stress. Currently, our understanding of the body defense mechanism against ACR toxicity is still limited. Given that hydrogen sulfide (H2S) has strong antioxidative actions and it shares several properties of ACR scavenger glutathione (GSH), we, therefore, tested whether H2S could be involved in ACR detoxification. Taking advantage of two cell lines that produced different levels of endogenous H2S, we found that the severity of ACR toxicity was reversely correlated with H2S-producing ability. In further support of the role of H2S, supplementing cells with exogenous H2S increased cell resistance to ACR, whereas inhibition of endogenous H2S sensitized cells to ACR. In vivo experiments showed that inhibition of endogenous H2S with CSE inhibitor markedly increased mouse susceptibility to the toxicity of cyclophosphamide and ACR, as evidenced by the increased mortality and worsened organ injury. Further analysis revealed that H2S directly reacted with ACR. It promoted ACR clearance and prevented ACR-initiated protein carbonylation. Collectively, this study characterized H2S as a presently unrecognized endogenous scavenger of ACR and suggested that H2S can be exploited to prevent and treat ACR-associated diseases.
