Organocatalytic stereoselective conjugate addition of 3-substituted oxindoles with in situ generated ortho-quinone methides

A novel method for the stereoselective conjugate addition of 3-substituted oxindoles to in situ generated o-QMs was described. This process was catalyzed efficiently by a cinchonidine-derived squaramide catalyst in oil-water phase, furnishing the corresponding 3,3-disubsituted oxindole derivatives in moderate to high yields (up to 98%) with high stereoselectivities (up to 95%?ee, 15.4:1?dr). The utility of this reaction was also investigated by the gram-scale synthesis and derivatization of one of the products.     

Application of mid-infared spectroscopy with multivariate analysis for the discrimination of toxic plant,Gelsemium elegans

Gelsemium elegans is a commonly used herb to treat different kinds of diseases. However, the indole alkaloid present in the plant might cause serious side effects. In this research, the infrared spectroscopic identification approach including Fourier transform infrared spectroscopy (FT-IR), Second derivative infrared spectra (SD-IR) and two-dimensional correlation infrared spectra (2D-IR) was used to develop a simple and rapid method to discriminate the stem, leaf and root of the Gelsemium elegans plant. This is because the stem, leaf and root contained different amount of indole alkaloid that contributed to the toxicity. Through this study, all the three parts were successfully identified and discriminated through the infrared spectroscopic identification method. The identification approach was also validated by comparing the samples of the mixture of both stem and root (SR) to the stem and root, respectively and also by comparing different plants with Gelsemium elegans plant. Besides that, all the samples of different parts of the Gelsemium elegans were analyzed with the Principal Component Analysis (PCA) and Soft Independent Modelling of Class Analogy (SIMCA) pattern recognition technique to test and verify the experimental results. The SIMCA model was validated by comparing 70 standard herbs to the model. From the results, macroscopic IR fingerprint method and the classification analysis successfully discriminate not only between Gelsemium elegans samples and standard herbs but also successfully distinguished the three different parts of Gelsemium elegans plant.     

Facile synthesis of blue-emitting carbon dots@mesoporous silica composite spheres

This paper reported a facile and effective approach towards high-efficient composite luminophores by embedding blue-emitting N-doped carbon dots into spherical SiO₂ matrix (CDs@SiO₂). Mesoporous silica microspheres (r-CDs@MSN) with strong luminescence were synthesized by removing CTAB templates in CDs@SiO₂ using reflux with acetone. The r-CDs@MSN possess a spherical morphology with smooth surface and a diameter of 130 nm, while it exhibits an excitation-independent blue emission peak at 440 nm with an internal quantum yield of 21.5%. BET result shows that the corresponding surface area and adsorption total pore volume are 156.27 m²/g and 0.682 cm³/g, which is suitable for the drugs loading and release. The results indicate that r-CDs@MSN might act as a potential fluorescent drug carrier.     

Thermo‐triggered Release of CRISPR‐Cas9 System by Lipid‐Encapsulated Gold Nanoparticles for Tumor Therapy

CRISPR/Cas9 system is a powerful toolbox for gene editing. However, the low delivery efficiency is still a big hurdle impeding its applications. Herein, we report a strategy to deliver Cas9‐sgPlk‐1 plasmids (CP) by a multifunctional vehicle for tumor therapy. We condensed CPs on TAT peptide‐modified Au nanoparticles (AuNPs/CP, ACP) via electrostatic interactions, and coated lipids (DOTAP, DOPE, cholesterol, PEG2000‐DSPE) on the ACP to form lipid‐encapsulated, AuNPs‐condensed CP (LACP). LACP can enter tumor cells and release CP into the cytosol by laser‐triggered thermo‐effects of the AuNPs; the CP can enter nuclei by TAT guidance, enabling effective knock‐outs of target gene (Plk‐1) of tumor (melanoma) and inhibition of the tumor both in vitro and in vivo. This AuNPs‐condensed, lipid‐encapsulated, and laser‐controlled delivery system provides a versatile method for high efficiency CRISPR/Cas9 delivery and targeted gene editing for treatment of a wide spectrum of diseases.     

Autothermal reforming of methane over Ni catalysts supported over ZrO2-CeO2-Al2O3

Ni catalysts supported on Al2O3, ZrO2-Al2O3, CeO2-Al2O3 and ZrO2-CeO2-Al2O3 were prepared by coprecipitation method, and their catalytic performances for autothermal reforming of methane to hydrogen were investigated. The Ni-supported catalysts were characterized by XRD, TPR and XPS. The relationship between the structures and catalytic activities of the catalysts was discussed. The results showed that the catalytic activity and stability of the Ni/ZrO2-CeO2-Al2O3 catalyst was better than those of other catalysts with the highest CH4 conversion, H2/CO and H2/COx ratio at 750 ℃. The catalyst showed a little deactivation along the reaction time during its 72 h on stream with the mean deactivation rate of 0.08%/h. The catalytic performance of the Ni/ZrO2-CeO2-Al2O3 catalyst was also affected by reaction temperature, no2 ： nCH4 molar ratio and nH2O ： nCH4 molar ratio. TPR, XRD and XPS measurements indicated that the formation of ZrO2-CeO2 solid solution could improve the dispersion of NiO, and inhibit the formation of NiAl2O3, and thus significantly promoted the catalytic activity of the Ni/ZrO2-CeO2-Al2O3 catalyst.     

苯并咪唑取代胺类及其金属配合物的研究与应用

概述了双苯并咪唑取代胺类、三苯并咪唑取代胺类及四苯并咪唑取代胺类配体及其金属配合物的研究和应用。研究报道,这些配体与人体必需的微量元素铜、锌、钴、镍、锰等金属形成的配合物能较好地模拟SOD分子中与金属离子配位的组氨酸的结构,且具有较好的拟SOD生物活性。     

Detection of new phenylpropanoids from Dendrobium chrysanthum

Herba Dendrobii has been documented in the Compendium of Materia Medica, with special efficacy in nourishing Yin and treating diabetes. However, the chemical profile of Dendrobium chrysanthum Lindl. has not been reported yet. The compositions were analysed with UPLC/Q-TOF-MS/MS. 53 compounds were tentatively characterised, and 14 compounds might be new compounds. Some novel lactones of poly-phenylpropanoids were firstly detected, and di-p-hydroxyphenylpropionic acidic p-coumaric acid lactone, a new compound of the first example, was obtained and identified. UPLC/Q-TOF-MS/MS was a feasible and efficient method to discover the unique compounds in complex matrices of D. chrysanthum.     

Two new hirsutane-type sesquiterpenoids chondrosterins N and O from the marine fungus Chondrostereum sp.

The marine fungus Chondrostereum sp. was collected from a soft coral Sarcophyton tortuosum from the South China Sea. This fungus was cultured in glucose-peptone-yeast (GPY) medium and the culture broth was extracted with EtOAc. By the method of ¹H NMR pre-screening and tracing the diagnostic proton signals of the methyl groups, two new hirsutane-type sesquiterpenoids, chondrosterins N and O (1 and 2) were isolated from the metabolite extracts. Their structures were elucidated on the basis of MS, 1D and 2D NMR data.     

Catalytic Reaction of Aryldiazoacetates with Indole and Its Derivatives:Profound Effect of N‐1 Substitutent on the Reaction Pathways

The reaction of indole and its derivatives with aryldiazoacetates has been studied in the presence of copper and rhodium catalysts. The electronic property of N-1 substitutent showed significant effect on the reaction pathways. The electron-donating group favored the formation of the β-alkylation products, while the electron-withdrawing group favored the formation of the cyclopropane products. A reaction mechanism was proposed based on the experimental data and previous research results. The structure of aryl group in diazo compounds also affected the yield of the β-alkylation products or the cyclopropane products.