Design, synthesis, and biological evaluation of anti-EV71 agents.

Enterovirus 71 (EV71) is a major causative agent of hand, foot and mouth disease (HFMD), which can spread its infections to the central nervous and other systems with severe consequences. In this article, design, chemical synthesis, and biological evaluation of various anti-EV71 agents which incorporate Michael acceptors are described. Further SAR study demonstrated that lactone type of Michael acceptor provided a new lead of anti-EV71 drug candidates with high anti-EV71 activity in cell-based assay and enhanced mouse plasma stability. One of the most potent compounds (2K, cell-based anti-EV71 EC50=0.028µM), showed acceptable stability profile towards mouse plasma, which resulted into promising pharmacokinetics in mouse via IP administration.

Byproduct-catalyzed four-component reactions of aldehydes with hexamethyldisilazane, chloroformates, and nucleophiles in acetonitrile leading to protected primary amines, beta-amino esters, and beta-amino ketones.

Multicomponent reactions are a very powerful tool for the construction of complex organic molecules by using readily available starting materials. While most of the multicomponent reactions discovered so far consist of three components, the reactions with four or more components remain sparse. We have successfully developed several four-component reactions using a catalytic amount of water as a hydrolyzing agent to decompose byproduct chlorotrimethylsilane (TMSCl) to yield secondary byproduct HCl that serves as a catalyst. In the presence of 40 mol % of water, the four-component reaction of aldehydes with hexamethyldisilazane (HMDS), chloroformates, and silylated nucleophiles proceeds smoothly at room temperature to give a range of protected primary amines in moderate to excellent yields. Importantly, a wide variety of protic carbon nucleophiles, such as beta-keto esters, beta-diketones, and ketones, have further been explored as suitable substrates for the synthesis of protected beta-amino esters and beta-amino ketones that are useful building blocks for various pharmaceuticals and natural products. These four-component reactions proceed through a pathway of tandem nitrogen protection/imine formation/imine addition, and the decomposition of byproduct TMSCl, generated in the first step of nitrogen protection, with water results in the formation of secondary byproduct HCl, a strong Brønsted acid that catalyzes the following imine formation/imine addition. Taking advantage of the fact that alcohols or phenols are also able to decompose byproduct TMSCl to yield secondary byproduct HCl, no catalyst is needed at all for the four-component reactions with aldehydes bearing hydroxy groups.

[Total flavones derived from Lagotis brevituba maxim reduce the levels of inflammatory cytokines in cerebral cortex and hippocampus of Alzheimer's disease mice].

Objective To investigate the mechanism behind the treatment of Alzheimer's disease (AD) with total flavones derived from Lagotis brevituba maxim (TF-LBM). Methods Fifty SAMP8 mice (aged 8 months) were randomly divided into 5 groups, (150, 300, 600) mg/kg TF-LBM groups, 0.65 g/kg donepezil HCl group and AD model group; 10 SAMR1 mice (aged 8 months) were used as a control group of normal aging. The AD model group and the normal aging control group were given the same volume of distilled water as TF-LBM groups. Eight weeks after intragastric administration, Morris water maze experiment was conducted to calculate the latency of place navigation. After the behavioral experiment, the brain cortical tissue and hippocampus (CA1 region) of the mice from various groups were taken to observe the morphological changes of the cortical tissue and hippocampus and test IL-1ß, IL-6, TNF-α content. Results Compared with the model group, the escape latency of the normal aging group, the high-dose TF-LBM group and the donepezil HCl group were evidently shortened; compared with the normal aging group, IL-1ß, IL-6, TNF-αof the model group increased significantly; compared with the model group, IL-1ß content of the low-dose TF-LBM group had no obvious difference, while IL-1ß content of the median-dose and high-dose TF-LBM groups and the donepezil HCl group decreased significantly; IL-6 content decreased in all TF-LBM groups and the donepezil HCl group; TNF-α level in the low-dose and median-dose TF-LBM groups had no evident difference, while it was reduced significantly in the high-dose TF-LBM group and the donepezil HCl group. Compared with the normal aging group, IL-1ß, IL-6 and TNF-α content of the model group increased significantly; compared with the model group, IL-1ß, IL-6 and TNF-α content of all TF-LBM groups and the donepezil HCl group decreased. Conclusion TF-LBM can improve the behavior change of SAMP8 mice with AD. TF-LBM can reduce the content of IL-6, IL-1ß and TNF-α in cerebral cortex and hippocampus CA1.

Catalytic coupling of N-benzylic sulfonamides with silylated nucleophiles at room temperature.

In the presence of 2-10 mol% of Tf(2)NH, a range of N-benzylic sulfonamides smoothly react with allylic, propargylic, benzylic, or hydrido silanes at room temperature via sp(3) carbon-nitrogen bond cleavage to afford structurally diverse products in moderate to excellent yields and with high chemo- and regioselectivity.

FeSO4 x 7H2O-catalyzed four-component synthesis of protected homoallylic amines.

An efficient catalytic four-component reaction of carbonyl compounds (or acetals/ketals), benzyl chloroformate (CbzCl), 1,1,1,3,3,3-hexamethyldisilazane (HMDS), and allyltrimethylsilane has been successfully developed to produce Cbz-protected homoallylic amines in the presence of 5 mol % of iron(II) sulfate heptahydrate (FeSO4 x 7H2O), an inexpensive and environmentally friendly catalyst, at room temperature.