Mechanism and origin of enantioselectivity for organocatalyzed asymmetric heteroannulation of alkynes in the construction of axially chiral C2-arylquinoline.

Axially chiral C2-arylquinoline has been successfully constructed via asymmetric heteroannulation of alkynes catalyzed by chiral phosphoric acid with high yield and high enantioselectivity. Inspired by this intriguing work, theoretical calculations have been carried out, and the detailed reaction mechanism has been elaborated, in which the whole reaction can be divided into steps including hydrogen transfer, C-N bonding, annulation reaction and the final dehydration processes. The initial hydrogen-transfer reaction has two possible pathways, while the subsequent C-N bonding process has eight possible pathways. Then, after the annulation reaction and the final dehydration processes, the major product and byproduct were formed. QTAIM and IGMH analyses were used to illustrate the role of weak intermolecular interactions in the catalytic process, and the distortion/interaction and EDA analyses provided a deeper understanding of the origin of enantioselectivity. The calculated results are consistent with the experimental results. This work would provide valuable insights into asymmetric reactions catalyzed by chiral phosphoric acid.

Clinical Efficacy of Infliximab in Patients With Crohn Disease in Different Locations of Disease Pathology: A Meta-Analysis.

PURPOSE: Infliximab (INX) has been approved for treating Crohn disease (CD) for many years, showing promis-ing efficacy in the clinic. However, the efficacy of the drug and the prognosis of CD vary significantly with dif-ferent locations of disease pathology. This study evaluated the efficacy of INX and prognosis in CD in different locations of disease pathology using systematic meta-analysis. METHODS: We used "Infliximab OR Remicade OR Avakine OR Inflectra OR Renflexis OR Remsima OR IgG1k monoclonal antibody" AND "Crohn's disease OR IBD OR inflammatory bowel disease" as search strategies for searching in PubMed, Wanfang and Embase. A systematic meta-analysis for overall proportions was used to analyze the data. RESULTS: Twelve studies involving 1,978 patients were included. The results confirmed that treatment with INX led to high clinical remission rates (82%, 95% CI: 64%-92%) and low relapse rates (4%, 95% CI: 2%-9%) in patients with CD. Our results also indicated that use of INX in patients with colon only (L2) CD led to lower clinical remission rates, and use of INX in patients with ileum and colon (L3) CD led to higher relapse rates. CONCLUSION: Our findings show different remission rates depending on location of the disease and may be useful for clinicians' choice of therapeutics.

Adenovirus-mediated NDRG2 inhibits the proliferation of human renal cell carcinoma cell line OS-RC-2 in vitro.

The objective of the study is to investigate the inhibitory effects of adenovirus-mediated N-Myc downstream-regulated gene 2 (NDRG2) on the proliferation of human renal cell carcinoma cell line OS-RC-2 in vitro. NDRG2 was harvested by RT-PCR, confirmed by DNA sequencing, and then cloned into the eukaryotic expression vector pIRES2-EGFP, which encodes green fluorescent protein (GFP), to construct pIRES2-EGFP-NDRG2 plasmid. OS-RC-2 cells with NDRG2 negative expression were transfected with pIRES2-EGFP-NDRG2 plasmid. The growth of transfected OS-RC-2 cells was observed under the light and fluorescence microscopes. After colony-forming cell assays, cell proliferation detection, and MTT assays, the growth curves of cells in each group were plotted to investigate the inhibitory effects of adenovirus-mediated NDRG2 on the proliferation of OS-RC-2 cells. Cell cycle was determined by flow cytometry. Confocal laser scanning microscopy was applied to determine the specific location of NDRG2 protein in subcellular level. A eukaryotic expression vector pIRES2-EGFP-NDRG2 was successfully constructed. After NDRG2 transfection, the growth of OS-RC-2 cells was inhibited. Flow cytometry showed that cells were arrested in S phase but the peak of cell apoptosis was not present, and confocal laser scanning microscopy showed that NDRG2 protein was located in mitochondrion. In conclusion, NDRG2 can significantly inhibit the proliferation of OS-RC-2 cells in vitro and its protein is specifically expressed in the mitochondrion.