Nanoengineered Design of inside-Heating Hot Nanoreactor Surrounded by Cool Environment for Selective Hydrogenations.

Catalysts with designable intelligent nanostructure may potentially drive the changes in chemical reaction techniques. Herein, a multi-function integrating nanocatalyst, Pt-containing magnetic yolk-shell carbonaceous structure, having catalysis function, microenvironment heating, thermal insulation, and elevated pressure into a whole is designed, which induces selective hydrogenation within heating-constrained nanoreactors surrounded by ambient environment. As a demonstration, carbonyl of α, ß-unsaturated aldehydes/ketones are selectively hydrogenated to unsaturated alcohols with a >98% selectivity at a nearly complete conversion under mild conditions of 40 °C and 3 bar instead of harsh requirements of 120 °C and 30 bar. It is creatively demonstrated that the locally increased temperature and endogenous pressure (estimated as ≈120 °C, 9.7 bar) in the nano-sized space greatly facilitate the reaction kinetics under an alternating magnetic field. The outward-diffused products to the "cool environment" remain thermodynamically stable, avoiding the over-hydrogenation that often occurs under constantly heated conditions of 120 °C. Regulation of the electronic state of Pt by sulfur doping of carbon allows selective chemical adsorption of the CO group and consequently leads to selective hydrogenation. It is expected that such a multi-function integrated catalyst provides an ideal platform for precisely operating a variety of organic liquid-phase transformations under mild reaction conditions.

Copper-Catalyzed Cascade Cyclization Reactions of Diazo Compounds with tert-Butyl Nitrite and Alkynes: One-Pot Synthesis of Isoxazoles.

A novel copper-catalyzed [3 + 2] cycloaddition reaction of alkynes with nitrile oxides generated in situ from the coupling reaction of copper carbene and nitroso radical has been developed. The three-component reaction provides a simple and efficient method for the construction of isoxazoles in a highly regioselective manner in a single step. On the basis of the experimental results and density functional theory calculations, a catalytic cycle (CuI-CuII-Cu0-CuI) for this cascade cyclization reaction is proposed.

Withanolides and aromatic glycosides isolated from Nicandra physaloides and their anti-inflammatory activity.

Two new withanolides (1-2) together with five known ones (3-7), and three known aromatic glycosides (8-10) were isolated from the dried stems and leaves of Nicandra physaloides, an edible and medicinal plant. Their structures were identified by extensive spectroscopic analyses or comparison with literature data. The absolute configuration of 2 was assigned via X-ray crystallography. Compound 1 with a spiroketal moiety is relatively unusual in withanolides. Aromatic glycosides (8-10) showed potent inhibitory activity against LPS-induced nitric oxide production in RAW 264.7 macrophages, with IC50 values from 4.69 to 16.12 µM.

Constituents from Apium graveolens and their anti-inflammatory effects.

A phthalide glycoside, (3R, 4R)-4-O-ß-D-glucopyranosyl-senkyunolide (1), and a megastigmane glycoside, (6S, 7R)-3-oxo-megastigma-4, 8-dien-7-O-ß-D-glucoside (2), along with two known aglycones (3-4), were isolated from the 70% EtOH extract of fresh whole grass of Apium graveolens L. Their structures were elucidated by extensive spectroscopic analysis. All of these compounds were tested for their inhibitory effects on nitric oxide (NO) production in the RAW 264.7 macrophages. Among them, compounds 3 and 4 showed potent inhibitory activity against LPS-induced nitric oxide production in RAW 264.7 macrophages, with IC50 values of 24.0 ± 2.1 µM and 28.6 ± 2.4 µM, respectively.

Physapubescin, a natural withanolide as a kidney-type glutaminase (KGA) inhibitor.

Kidney-type glutaminase (KGA) is over expressed in many kinds of cancers that converts glutamine to glutamate for supplying energy, and has become an object for targeted cancer therapy. The structure-based virtual ligand screening identified physapubescin, a withanolide purified from Physalis pubescens L., as a possible inhibitor of KGA with low binding energy. Enzyme inhibition experiments and cell-based assays further confirmed its inhibitory effects on KGA activity, suggesting potential applications of physapubescin and its derivatives as KGA inhibitors.

Two pairs of farnesyl phenolic enantiomers as natural nitric oxide inhibitors from Ganoderma sinense.

Four new farnesyl phenolic compounds, ganosinensols A-D (1-4) were isolated from the 95% EtOH extract of the fruiting bodies of Ganoderma sinense. Two pairs of enantiomers, 1/2, and 3/4 were isolated by HPLC using a Daicel Chiralpak IE column. Their structures were elucidated from extensive spectroscopic analyses and comparison with literature data. The absolute configurations of 1-4 were assigned by ECD spectra. All of these isolated compounds showed potent inhibitory activity against LPS-induced nitric oxide production in RAW 264.7 macrophages, with IC50 values from 1.15 to 2.26µM.