Cerium oxide (CeO2) was tested as a packing material in liquid chromatography for the separation of C60 and C70 fullerenes. The separation of C60 and C70 fullerenes could be achieved within 20 min by using pure n-hexane as the mobile phase. Furthermore, some higher fullerenes could also be separated in less than 40 min. The peak area was reproducible to a large extent. The separation of fullerenes by liquid chromatography on CeO2 is shown to be an effective method for their isolation in large amounts. The column efficiency of the CeO2 column was compared with commercial silica gel and ODS columns. The main advantage of the CeO2 column is its ability to separate large amounts of fullerenes (C60 and C70) in toluene. 相似文献
Platinum‐group metals on activated carbon catalysts, represented by Pd/C, Ru/C, Rh/C, etc., are widely utilized to accomplish green and sustainable organic reactions due to their favorable features, such as easy handling, recoverability, and reusability. The efficient oxidation methods of various organic compounds using heterogeneous platinum‐group metals on carbons with or without added oxidants are summarized in this Personal Account. The oxidation of internal alkynes into diketones was effectively catalyzed by Pd/C in the presence of dimethyl sulfoxide and molecular oxygen or pyridine N‐oxide. The Pd/C‐catalyzed mild combustion of gaseous hydrogen with molecular oxygen provided hydrogen peroxide, which could be directly utilized for the oxidation of sulfide derivatives into sulfoxides. Furthermore, the Ru/C‐catalyzed aerobic oxidation of primary and secondary alcohols gave the corresponding aldehydes and ketones, respectively. On the other hand, the dehydrogenative oxidation of secondary alcohols into ketones was achieved using Rh/C in water, and primary alcohols were effectively dehydrogenated by Pd/C in water under mildly reduced pressure to produce carboxylic acids.
The phase‐transition behaviors, crystal structures, and dielectric properties of four kinds of simple 1:1 organic salts of (C12H25NH3+)(benzenesulfonate) and (C12H25NH3+)(pyridine sulfonates) were examined from the viewpoint of intermolecular hydrogen‐bonding interactions and dynamic conformational transformation in molecular assemblies. Crystals of (C12H25NH3+)(benzenesulfonate) and (C12H25NH3+)(3‐pyridinesulfonate) were isostructural and solid–solid and solid–liquid‐crystal smectic A (SmA) phase transitions were observed. These two crystals formed rodlike cation–anion assemblies. However, the two salts, (C12H25NH3+)(2‐pyridinesulfonate) and (C12H25NH3+)(4‐pyridinesulfonate), formed largely bent L ‐shaped cation–anion conformations. Interesting conformational transformations from rodlike to L ‐shaped assemblies were observed in (C12H25NH3+)(2‐pyridinesulfonate) and (C12H25NH3+)(3‐pyridinesulfonate). 相似文献
The oxidation of 10–10′ singly linked corrole dimers with DDQ at low concentration in CHCl3 afforded meso–meso, β–β, β–β triply linked 2H‐corrole dimers (with two inner NH groups in each corrole unit), which exhibited characteristic 1H NMR and absorption spectra attributable to their nonaromatic electronic networks. These 2H‐corrole dimers were reduced with NaBH4 to aromatic 3H‐corrole dimers, which were unstable and easily oxidized back to the 2H‐corrole dimers upon exposure to air. Bis(zinc(II)) complexes of the 2H‐corrole dimers were synthesized and characterized as rare examples of nonaromatic zinc(II) corrole complexes. 相似文献
2-DE is one of the most powerful methods for analyzing proteins expressed in cells and tissues. Immunodetection of proteins blotted on a polymer membrane is the method of choice for detecting specific proteins in 2-D gels. To precisely locate spots of immunoreactive proteins in 2-D gels, both dye staining and immunodetection were performed on the same PVDF membrane. Prior to immunodetection, nonspecific adsorption of the antibodies to the membrane was blocked with a synthetic polymer-based reagent (N-102) after protein transfer. The protein was then stained with colloidal gold or CBB followed by protein spot identification by LC-MS. Described herein is a method for multiplex analysis of proteins transferred to a PVDF membrane. Proteins that were phosphorylated at tyrosine in the phosphoproteome of rice callus or human ovarian cancer cells were detected by immunoblotting and subsequently identified with high precision. 相似文献
A lipoplex (i.e., pDNA#1/lipid complex and transfection reagent for pDNA delivery) containing galactosylceramide (GalCer) and an amidine-bearing lipid (TRX) was examined whether the bound pDNA was specifically ingested by hepatocyte via asialoglycoprotein receptor (ASGPR) and then expressed protein. Gel electrophoresis and small-angle X-ray scattering (SAXS) confirmed that the TRX-GalCer liposome#2 complexed with pDNA and the resultant lipoplex took a hexagonally packed inverted cylinder structure when the GalCer composition was less than 20 wt.% of the total lipid. When the lipoplex carrying pGL3 (luciferase-cording pDNA) was administrated to HepG2, the luciferase activity was increased with increasing the GalCer composition until it reached 3 wt.% and then decreased upon further addition of GalCer. When we added galactose itself as a competitor, the luciferase activity was decreased, while glucose did not show such decrease, suggesting that HepG2 ingested the lipoplex via ASGPR-mediated endocytosis. This paper indicated that the hexagonally packed inverted cylinder structures of lipoplex may not always provide excellent transfection and presented a possibility that the TRX lipoplex#3 can obtain a cellulartargeting ability through the receptors for oligosaccharide. 相似文献
A collection of plants from the country of Georgia (Galanthus caucasicus, Magnolia obovata, Cocculus laurifolius, and Veratrum lobelianum) has been studied for their alkaloid content. Our studies led to the isolation and identification of 24 alkaloids, three of which are being identified and reported for the first time. 相似文献
A reactive radical species, nitric oxide (NO), was encapsulated in a unimolecular form inside an open‐cage fullerene derivative under high‐pressure conditions in the solid state. Surprisingly, the molecular complex showed sharp 1H NMR signals despite the existence of the paramagnetic species inside the carbon cage. Owing to the paramagnetic shifts, the escape rate of the NO was determined experimentally. After constructing a stopper on the rim of the opening, the NO was found to stay inside the cage even at 50 °C. The ESR measurements of the powdery sample showed paramagnetic properties at low temperature. The single‐crystal X‐ray structure analysis clearly demonstrated the existence of the encapsulated NO molecule, suggesting rapid rotation inside the cage. The 1H NMR chemical shifts displayed a large temperature dependence owing to the paramagnetic effects. 相似文献