Copper(ii)-catalyzed synthesis of multisubstituted indoles through sequential Chan-Lam and cross-dehydrogenative coupling reactions.

Starting from arylboronic acids and ester ()-3-aminoacrylates, one-pot syntheses of diverse indole-3-carboxylic esters have been described through copper(ii)-catalyzed sequential Chan-Lam -arylation and cross-dehydrogenative coupling (CDC) reactions. The initial Chan-Lam arylation can proceed in DMF at 100 °C for 24 h to give ester ()-3-(arylamino)acrylate intermediates in the presence of Cu(OAc)/tri--butylphosphine tetrafluoroborate, a catalytic amount of myristic acid as the additive, KMnO and KHCO. Sequentially, these arylated intermediates can undergo an intramolecular oxidative cross-dehydrogenative coupling process in mixed solvents (DMF/DMSO = 2 : 1) at 130 °C to give C3-functionalized multi-substituted indole derivatives.

Tunable synthesis of quinolinone-fused isoquinolines through sequential one-pot nucleophilic addition and palladium-catalyzed intramolecular C-H alkenylation.

An efficient sequential one-pot synthesis of fused heterocycles based on 4-quinolinone and isoquinoline scaffolds of biological interest has been developed. In all cases, the first nucleophilic addition of 2-aryl quinolin-4(1H)-ones to alkynyl bromides in tert-pentyl alcohol can proceed in a chemo-, regio- and stereoselective manner to give (Z)-N-(1-bromo-1-alken-2-yl)quinolin-4-ones at 110 °C. Sequentially, these in situ functionalized adducts can undergo direct intramolecular aromatic C-H alkenylation in the presence of PdCl2 (5 mol%) in mixed solvents (tert-pentyl alcohol/DMF = 1 : 1), affording the novel quinolinone-fused isoquinoline derivatives in good yields.

Synthesis of 4H-Chromen-4-one Derivatives by Intramolecular Palladium-Catalyzed Acylation of Alkenyl Bromides with Aldehydes.

The palladium-catalyzed intramolecular acylation of alkenyl bromides and aldehydes was developed for an efficient synthesis of 4H-chromen-4-ones. With Pd(PPh)/Xphos as the catalyst and KCO as the base, this protocol was applied to synthesize a small library of diversely functionalized flavonoids in moderate to good yields in 1,4-dioxane.

[Antioxidant activity of different extracts from Astragalus mongholicus].

Objective: To study the antioxidant activities of different extracts from Astragalus mongholicus.

Method: The antioxidant activities of the total flavanoids (TFA), the total saponins (TSA) and the total polysaccharides (TPA) from A. mongholicus were measured by means of biochemiluminescence.

Astragaloside IV improved intracellular calcium handling in hypoxia-reoxygenated cardiomyocytes via the sarcoplasmic reticulum Ca-ATPase.

Although astragaloside IV, a saponin isolated from Astragalus membranaceus, has been shown to protect the myocardium against ischemia/reperfusion injury, its effect on the status of sarcoplasmic reticulum (SR) Ca2+ transport in the injured myocardium remains largely unknown. In this study, we investigated whether in cultured cardiomyocytes subjected to hypoxia and reoxygenation (H/R) administration of astragaloside IV during H/R attenuates the myocardial cell injury and prevents changes in Ca2+ handling activities and gene expression of SR Ca2+ pump. Cultured cardiomyocytes from neonatal rats were exposed to 6 h of hypoxia followed by 3 h of reoxygenation.

Protective effect of astragalosides on myocardial injury by isoproterenol in SD rats.

We have extracted and roughly purified astragalosides (AS) from Astragalus membranaceus, a natural herb used as a traditional Chinese medicine, regarded to have pharmacodynamic benefits of protecting injured myocardium. We hypothesized that the astragalosides might exert beneficial effect in myocardial lesion by preserving both energy metabolism and Ca(2+) homeostasis. Sprague-Dauley (SD) rats were injected with isoproterenol (ISO) subcutaneous (s.

Simultaneous analysis of seven astragalosides in Radix Astragali and related preparations by liquid chromatography coupled with electrospray ionization time-of-flight mass spectrometry.

A method has been developed for the qualitative and quantitative analysis of pharmacologically active astragalosides isolated from several species of the genus Astragalus by high performance liquid chromatography coupled with electrospray ionization time-of-flight mass spectrometry. Seven astragalosides in Radix Astragali and their commercial pharmaceutical preparations were analyzed using the developed method. The extracted ion current chromatograms were obtained from the total ion current chromatogram using the m/z of [M+Na]+ ions produced by target compounds for peak determination.

Effect of astragalosides on intracellular calcium overload in cultured cardiac myocytes of neonatal rats.

Astragalosides were the main active components from a native Chinese herb Astragalus membranaceus. Recent studies have shown that Astragalosides have a protective effect on myocardial injury in rats. The present study was designed to investigate the effect of Astragalosides on intracellular calcium overload and sarcoplasmic reticulum calcium load (SR Ca2+ load) in cultured cardiac myocytes from neonatal rats.