Catalytic Asymmetric Peroxidation of α,β-Unsaturated Nitroalkenes by a Bifunctional Organic Catalyst

A new enantioselective peroxidation of α,β-unsaturated nitroalkenes was realized with an easily accessible acid–base bifunctional organic catalyst derived from cinchona alkaloids. This reaction provides unprecedented easy access to optically active chiral peroxides, as illustrated by the asymmetric synthesis of β-peroxy nitro compounds

Catalytic Enantioselective Peroxidation of α,β-Unsaturated Aldehydes for the Asymmetric Synthesis of Biologically Important Chiral Endoperoxides

We have developed an unprecedented highly enantioselective catalytic peroxidation of enals. Critical to this development is the discovery that varying the structure of the hydroperoxide has a significant impact on the enantioselectivity of the organocatalytic asymmetric peroxidation. This novel transformation enabled the development of an enantioselective route toward the core structure shared by all members of the stolonoxide family of anticancer natural products, a connected <i>trans</i>-3,6-disubstituted-1,2-dioxane and <i>trans</i>-2,5-disubstituted-tetrahydrofuran ring system. Our route also features an unprecedented cyclization cascade of a chiral bis­(epoxy)­hydroperoxide. The new methodology and synthetic strategy established in this work should be applicable to the enantioselective synthesis of a broad range of chiral 1,2-dioxolanes and 1,2-dioxanes, thereby facilitating biological and medicinal chemistry studies of peroxy natural products

A Vancomycin-Templated DNA-Encoded Library for Combating Drug-Resistant Bacteria

It is an urgent need to tackle the global crisis of multidrug-resistant bacterial infections. We report here an innovative strategy for large-scale screening of new antibacterial agents using a whole bacteria-based DNA-encoded library (DEL) of vancomycin derivatives via peripheral modifications. A bacterial binding affinity assay was established to select the modification fragments in high-affinity compounds. The optimal resynthesized derivatives demonstrated excellently enhanced activity against various resistant bacterial strains and provided useful structures for vancomycin derivatization. This work presents the new concept in a natural product-templated DEL and in antibiotic discovery through bacterial affinity screening, which promotes the fight against drug-resistant bacteria

A Vancomycin-Templated DNA-Encoded Library for Combating Drug-Resistant Bacteria

It is an urgent need to tackle the global crisis of multidrug-resistant bacterial infections. We report here an innovative strategy for large-scale screening of new antibacterial agents using a whole bacteria-based DNA-encoded library (DEL) of vancomycin derivatives via peripheral modifications. A bacterial binding affinity assay was established to select the modification fragments in high-affinity compounds. The optimal resynthesized derivatives demonstrated excellently enhanced activity against various resistant bacterial strains and provided useful structures for vancomycin derivatization. This work presents the new concept in a natural product-templated DEL and in antibiotic discovery through bacterial affinity screening, which promotes the fight against drug-resistant bacteria

In Vivo Study of the Efficacy of the Essential Oil of <i>Zanthoxylum bungeanum</i> Pericarp in Dextran Sulfate Sodium-Induced Murine Experimental Colitis

The purpose of this study was to investigate the protective effects and mechanisms of the essential oil of <i>Zanthoxylum bungeanum</i> pericarp (ZBEO) on dextran sulfate sodium (DSS)-induced experimental colitis in mice. ZBEO decreased DSS-induced body weight loss, the disease activity index, colon length shortening, colonic pathological damage, and myeloperoxidase activities. The production of pro-inflammatory mediators was significantly alleviated by ZBEO. Further mechanistic analysis showed that ZBEO inhibited inflammation by regulating NF-κB and PPARγ pathways. ZBEO also inhibited NLRP3 activation in colitis in mice. Furthermore, ZBEO contributed to the maintenance of tight junction architecture by regulating the expression of zonula occludens-1 during colitis. Surprisingly, treatment with ZBEO increased levels of the commensal bacteria containing <i>Lactobacillus</i> and <i>Bifidobacteria</i> but reduced <i>Escherichia coli</i> levels in the feces of mice. These results suggested that supplementation with ZBEO might provide a new dietary strategy for the prevention of ulcerative colitis