Asymmetric Aziridination of <i>N</i>‑Sulphonyl Ketimines with Unfunctionalized Ketones: A One-pot Approach to Multisubstituted Fused Aziridines

A highly diastereo- and enantioselective aziridination of <i>N</i>-sulphonyl ketimines with unfunctionalized ketones was reported. In this efficient method, a sequential direct asymmetric Mannich reaction and oxidative C–H amination were involved, which enabled a straightforward route to multisubstituted-fused aziridines in one pot. More importantly, two different products could be selectively obtained in the reaction by adding or removing a metal additive

Antiangiogenic phenylpropanoid glycosides from <i>Gynura cusimbua</i>

<p>A new phenylpropanoid glycoside, named <i>α</i>-L-rhamnopyranosyl-(1↔2)-<i>β</i>-D-[4″-(8<i>E</i>)-7-(3,4-dihydroxyphenyl)-8-propenoate, 1″-O-(7<i>S</i>)-7-(3,4-dihydroxyphenyl)-7-methoxy-ethyl]-glucopyranoside (<b>1</b>), together with nine known compounds (<b>2–10</b>) were isolated from the active fraction (<i>n</i><b>-</b>Butanol fraction) of <i>Gynura cusimbua</i> for the first time. The known compounds (<b>2–10</b>) were identified as phenylpropanoid glycosides on the basis of extensive spectral data and references. The antiangiogenic activities of compounds (<b>1–10</b>) were evaluated by MTT assay on HUVECs and wild-type zebrafish <i>in vivo</i> model assay. As a result, compounds <b>1</b>, <b>6</b>, <b>7</b>, <b>8</b> and <b>10</b> exhibited certain antiangiogenic activities.</p

Synthesis of 1,3-Disubstituted Imidazo[1,5‑<i>a</i>]pyridines from Amino Acids via Catalytic Decarboxylative Intramolecular Cyclization

A copper/iodine cocatalyzed decarboxylative cyclization of α-amino acids is described. Starting from the readily available amino acids and either 2-benzoylpyridines or 2-benzoylquinolines, 1,3-disubstituted imidazo­[1,5-<i>a</i>]­pyridines and 1,3-disubstituted imidazo­[1,5-<i>a</i>]­quinolines were prepared in excellent yields

Scalable Electrochemical Dehydrogenative Lactonization of C(sp²/sp³)–H Bonds

A practical, electrochemical method is developed for the direct dehydrogenative lactonization of C­(sp²/sp³)–H bonds under external oxidant- and metal-free conditions, delivering diverse lactones, including coumarin derivatives with excellent regioselectivity. The scalable nature of this newly developed electrochemical process was demonstrated on a 40 g scale following an operationally simple protocol. The remote lactonization of C­(sp³)–H bonds would constitute an important synthetic advance toward electrochemical C–O bond formation

Rhodium-Catalyzed/Copper-Mediated Tandem C(sp²)–H Alkynylation and Annulation: Synthesis of 11-Acylated Imidazo[1,2‑<i>a</i>:3,4‑<i>a</i>′]dipyridin-5-ium-4-olates from 2<i>H</i>‑[1,2′-Bipyridin]-2-ones and Propargyl Alcohols

A rhodium-catalyzed/copper-mediated tandem C­(sp²)–H alkynylation and intramolecular annulation of 2<i>H</i>-[1,2′-bipyridin]-2-ones with propargyl alcohols for the synthesis of 11-acylated imidazo­[1,2-<i>a</i>:3,4-<i>a</i>′]­dipyridin-5-ium-4-olates is described

Cp*Co^III-Catalyzed Synthesis of Pyrido­[2′,1′:2,3]­pyrimido­[1,6‑<i>a</i>]­indol-5-iums via Tandem C–H Activation and Subsequent Annulation from 1‑(Pyridin-2-yl)‑1<i>H</i>‑indoles and Internal Alkynes

A Cp*Co^III-catalyzed C2-selective C–H alkenylation/annulation cascade transformation of 1-(pyridin-2-yl)-1<i>H</i>-indoles with internal alkynes to afford pyrido­[2′,1′:2,3]­pyrimido­[1,6-<i>a</i>]­indol-5-iums is presented. Moreover, 6,7-dihydro-4<i>H</i>-pyrido­[2′,1′:2,3]­pyrimido­[1,6-<i>a</i>]­indole, a new functionalized <i>N</i>-fused indole core heterocycle, could be constructed effectively via reduction of pyrido­[2′,1′:2,3]­pyrimido­[1,6-<i>a</i>]­indol-5-ium by NaBH₄

Hepatoprotective phenylethanoid glycosides from <i>Cirsium setosum</i>

<p>Two new phenylethanoid glycosides, namely <i>β</i>-D-glucopyranoside, 1″-<i>O</i>-(7<i>S</i>)-7-(3-methoxyl-4-hydroxyphenyl)-7-methoxyethyl-3″-<i>α</i>-L-rhamnopyranosyl-4″-[(8<i>E</i>)-7-(3-methoxyl-4-hydroxyphenyl)-8-propenoate] (<b>1</b>) and <i>β</i>-D-glucopyranoside, 1″-<i>O</i>-(7<i>S</i>)-7-(3-methoxyl-4-hydroxyphenyl)-7-methoxyethyl-3″-<i>α</i>-L-rhamnopyranosyl-4″-[(8<i>E</i>)-7-(4-hydroxyphenyl)-8-propenoate] (<b>2</b>), together with six phenylethanoid glycosides were isolated from <i>Cirsium setosum</i>. Their structures were elucidated by their spectroscopic data and references. Compounds <b>2</b>, <b>4</b>, <b>5</b>, <b>7</b> and <b>8</b> (10 μM) exhibited moderate hepatoprotective activities. Compounds (<b>3–8</b>) were obtained from this plant for the first time.</p

Mechanistic effect of the human GJB6 gene and its mutations in HaCaT cell proliferation and apoptosis

<div><p>We constructed lentiviral vectors containing the human wild-type GJB6 gene and the mutant variants A88V and G11R. The three proteins were stably expressed by the Tet-on system in the HaCaT cell line and used to study the functional effect of the variants. The CCK-8 assay and flow cytometric analyses were used to determine the levels of cell proliferation and apoptosis. Western blot analyses were performed to analyze the relevant clinical indicators of hidrotic ectodermal dysplasia and markers of apoptosis in transfected HaCaT cells. The CCK8 assay and the flow cytometry results showed a significant increase (P<0.05) in the apoptosis of HaCaT cells expressing the A88V and G11R mutants. In addition, we demonstrated that the A88V and G11R mutants induced the apoptosis of transfected HaCaT cells via the activation of caspase-3, -8, -9, and PARA. No change was observed in the activity of BAX compared with the control. This study provides further clarification on the mechanisms underlying the effect of the mutant variants A88V and G11R of the GJB6 gene on the induction of HaCaT cell apoptosis.</p></div