One-Pot Synthesis of Indolin-3-ones Mediated by LiN(SiMe3)2/CsF.

Indolin-3-ones are essential heterocycles with wide-ranging biological activities and medicinal values, and therefore, efficient approaches to their synthesis remain in demand. Herein, a novel and operationally simple method to generate indolin-3-ones is reported by using a tandem reaction of N-methylbenzylamines and methyl 2-fluorobenzoates mediated by the LiN(SiMe3)2 and CsF system (34 examples, 30-85% yields). The synthesis of C2-quaternary indolin-3-one further demonstrated the potential practicability of these tandem reactions.

Alkali-Amide-Catalyzed One-Pot Aminoallylation of Aldehydes with Allylbenzenes.

The deprotonation of allylbenzene was successfully demonstrated with a catalytic alkali amide base (NaN(SiMe3)2). The deprotonated allyl anion could be trapped by in situ generated N-(trimethylsilyl) aldimines to provide value-added homoallylic amines (39 examples, 68-98% yields) in a one-pot manner with excellent liner selectivity. Compared with the previously reported method for the synthesis of homoallylic amines, this method does not need to use the preinstalled protection groups on the imines, which need to be removed after the reaction to obtain the N-H free homoallylic amine derivatives.

One-Pot Rapid Access to Benzyl Silanes, Germanes, and Stannanes from Toluenes Mediated by a LiN(SiMe3)2/CsCl System.

Organo-silanes, germanes, and stannanes are considered to be conducive to the development of cross-coupling reactions because they are stable, nontoxic, and easy to handle. Using feedstock toluenes, one-pot direct benzylic C-H silylations, germylations, and stannylations are developed. Simply combining toluenes, LiN(SiMe3)2/CsCl, and R3MCl (M = Si, Ge, Sn) generates a diverse array of bench-stable benzyl silanes, germanes, and stannanes (38 examples, 53-90% yields). The syntheses developed here are easy to access on scale.

Benzylic Aroylation of Toluenes Mediated by a LiN(SiMe3)2/Cs+ System.

Chemoselective deprotonative functionalization of benzylic C-H bonds is challenging, because the arene ring contains multiple aromatic C(sp2)-H bonds, which can be competitively deprotonated and lead to selectivity issues. Recently it was found that bimetallic [MN(SiMe3)2 M = Li, Na]/Cs+ combinations exhibit excellent benzylic selectivity. Herein, is reported the first deprotonative addition of toluenes to Weinreb amides mediated by LiN(SiMe3)2/CsF for the synthesis of a diverse array of 2-arylacetophenones. Surprisingly, simple methyl benzoates also react with toluenes under similar conditions to form 2-arylacetophenones without double addition to give tertiary alcohol products. This finding greatly increases the practicality and impact of this chemistry. Some challenging substrates with respect to benzylic deprotonations, such as fluoro and methoxy substituted toluenes, are selectively transformed to 2-aryl acetophenones. The value of benzylic deprotonation of 3-fluorotoluene is demonstrated by the synthesis of a key intermediate in the preparation of Polmacoxib.

CircRNA_0026344 via exosomal miR-21 regulation of Smad7 is involved in aberrant cross-talk of epithelium-fibroblasts during cigarette smoke-induced pulmonary fibrosis.

For smoking-induced pulmonary fibrosis (PF), a serious disease endangering human health, there is no effective clinical treatment. Aberrant epithelium-fibroblast cross-talk is involved in formation of the excessive extracellular matrix (ECM) that contributes to PF. Circular RNAs have been associated with various pulmonary diseases. However, the mechanisms of circRNAs in PF are not clear. Herein, our goals were to investigate the involvement of circRNA_0026344 in the aberrant epithelium-fibroblast cross-talk induced by cigarette smoke (CS) and to define its mechanism. Chronic exposure (16 weeks) of BALB/c mice to 500 mg/m3 CS induced lung injury and fibrosis in lung tissues. From HBE cells, circRNA_0026344 was selected by microarray analysis and verified as that with the most severe down-regulation caused by cigarette smoke extract (CSE). The regulatory relationship between circRNA_0026344 and miR-21 was assessed by use of bioinformatics, RNA pull-down assays, and qRT-PCR. We found that miR-21 binding sites were present in circRNA_0026344 and, in HBE cells, it could act as a sponge for miR-21. When pcDNA3.0-circRNA_0026344, a high expression plasmid of circRNA_0026344, was transfected into HBE cells, the CSE-induced up-regulation of miR-21 levels was reversed. In MRC-5 cells, HBE-secreted exosomal miR-21 decreased levels of Smad7 and activated the TGF-ß1/Smad3 pathway. By using the Targetscan database, the presence of species-conserved miR-21 binding sites in the Smad7 3'UTR region were predicted. We verified, by use of a luciferase reporter gene, that miR-21 bound to the 3'UTR region of Smad7 mRNA to inhibit its transcription. In conclusion, the results reveal that, in CS-induced pulmonary fibrosis, circRNA_0026344, via exosomal miR-21 regulation of Smad7, is involved in aberrant cross-talk of epithelium-fibroblasts. These results will be useful for the discovery of early biomarkers and for providing therapeutic targets for smoking-induced pulmonary fibrosis.

Nickel-catalyzed reductive coupling of homoenolates and their higher homologues with unactivated alkyl bromides.

The catalytic generation of homoenolates and their higher homologues has been a long-standing challenge. Like the generation of transition metal enolates, which have been used to great affect in synthesis and medicinal chemistries, homoenolates and their higher homologues have much potential, albeit largely unrealized. Herein, a nickel-catalyzed generation of homoenolates, and their higher homologues, via decarbonylation of readily available cyclic anhydrides has been developed. The utility of nickel-bound homoenolates and their higher homologues is demonstrated by cross-coupling with unactivated alkyl bromides, generating a diverse array of aliphatic acids. A broad range of functional groups is tolerated. Preliminary mechanistic studies demonstrate that: (1) oxidative addition of anhydrides by the catalyst is faster than oxidative addition of alkyl bromides; (2) nickel bound metallocycles are involved in this transformation and (3) the catalyst undergoes a single electron transfer (SET) process with the alkyl bromide.

Downregulated lncRNA UCA1 accelerates proliferation and migration of vascular smooth muscle cells by epigenetic regulation of MMP9.

Function of long non-coding RNA urothelial carcinoma antigen 1 (lncRNA UCA1) in regulating the proliferative and migratory abilities of vascular smooth muscle cells (VSMCs) by mediating matrix metalloproteinase-9 (MMP9) level were elucidated. After treatment with different concentrations of ox-LDL for different time points, lncRNA UCA1 level in VSMCs was determined by quantitative real-time polymerase chain reaction (qRT-PCR). Subcellular distribution of UCA1 was analyzed. Proliferative and migratory abilities of VSMCs transfected with pcDNA-UCA1 were assessed. Protein level of MMP9 in HA-VSMCs treated with different concentrations of ox-LDL for different time points was also determined. The potential interaction between UCA1 and enhancer of zeste homolog 2 (EZH2) was identified by RNA immunoprecipitation (RIP) assay. Recruitment ability of EZH2 to MMP9 promoter region influenced by UCA1 was determined by Chromatin immunoprecipitation (ChIP) assay. Finally, the potential function of MMP9 in UCA1-mediated cellular behavior of VSMCs was explored. UCA1 was time-dependently and dose-dependently upregulated in VSMCs by ox-LDL treatment. Proliferative and migratory abilities of VSMCs were enhanced by treatment of 100 mg/l ox-LDL for 48 h, which were further reduced after transfection of pcDNA-UCA1. Subcellular distribution analysis showed that UCA1 was mainly distributed in the nucleus. Protein level of MMP9 was gradually elevated with the treatment of increased concentrations of ox-LDL in VSMCs. Its level was downregulated by transfection of pcDNA-UCA1 in VSMCs. The interaction between UCA1 and EZH2 was confirmed by RIP assay. Transfection of pcDNA-UCA1 stimulated the binding of EZH2 on MMP9 promoter region. Finally, overexpression of MMP9 reversed the decreased proliferative and migratory abilities in ox-LDL-treated VSMCs overexpressing UCA1. Downregulated UCA1 accelerates VSMCs to proliferate and migrate through negatively regulating MMP9 level.

The Antithrombotic Effects of Low Molecular Weight Fragment from Enzymatically Modified of Laminaria Japonica Polysaccharide.

BACKGROUND Laminaria japonica polysaccharide (LJP), a fucose enriched sulfated polysaccharide has been demonstrated to have excellent anticoagulant and antithrombotic activities. However, the antithrombotic effect of low molecular weight polysaccharide from enzymatically modified of LJP (LMWEP) remains unknown. MATERIAL AND METHODS LMWEP was prepared by fucoidanase enzymatic hydrolysis, and the antithrombotic and anticoagulant activities, and the underlying mechanism were investigated thoroughly. Rats were randomly divided into 6 groups (8 rats in each group): the blank control group, the blank control group treated with LMWEP (20 mg/kg), the model group, the model group treated with heparin (2 mg/kg), the model group treated with LJP (20 mg/kg), and the model group treated with LMWEP (20 mg/kg). After 7 days of intravenous administration, blood was collected for biochemical parameters examinations. RESULTS LMWEP increased the activated partial thromboplastin time (APTT), thrombin time (TT), prothrombin time (PT), 6-keto prostaglandin F1alpha (6-Keto-PGF1alpha), and endothelial nitric oxide synthase (eNOS). In addition, LMWEP decreased fibrinogen (FIB), endothelin-1 (ET-1), thromboxane B2 (TXB2), erythrocyte sedimentation rate (ESR), and hematocrit (HCT). CONCLUSIONS LMWEP, an enzymatically modified fragment with a molecular weight of 25.8 kDa, is a potential antithrombotic candidate for treatment of thrombosis related diseases.

A double-indole structure fluorescent probe for monitoring sulfur dioxide derivatives with distinct ratiometric fluorescence signals in mammalian cells.

Based on the addition reaction of the sulfur dioxide derivative to the CC double bond, the probe HDI was designed and synthesized. The two-channel fluorescent probe HDI changed from orange to colorless and the fluorescence changed from red to blue when the bisulfite was detected. And the probe responds rapidly to bisulfite within 2 min, with high sensitivity and specificity. In addition, the probe can be used to detect the concentration of bisulfite with a low detection limit (80 nM). Cytological experiments have also demonstrated that probe HDI has low cytotoxicity and could be used for ratiometric detection of sulfur dioxide derivatives in living cells.