New anthraquinone derivatives from the roots of Berchemia floribunda

A new naphthoquinone-anthraquinone dimer named floribundiquinone E(1)and a new anthraquinone 2-acetylphyscion(2)were isolated from the roots of Berchemia floribunda Brongn.Their structures were elucidated on the basis of spectroscopicmethods.     

Assembly and Immunogenicity of Human Papillomavirus Type 16 Major Capsid Protein（ HPV16 L1） in Pichia pastoris

IntroductionHPV16 L1 protein can self-assemblein vitrointovirus-like particles(VLPs),the morphology of which issimilar to that of native virions[1]. Human papilloma-viruses(HPV) belong to a family of nonenveloped,double-stranded DNA viruses, and more than…     

(Z)-a-Selanyl Alkenyl Grignard Reagents as Convenient Precursors for Stereoselective Synthesis of Trisubstituted Alkenes

Many biologically active compounds occurring in nature possess the structural skeleton of trisubstituted alkenes1-3. Difunctional group reagents, which have two different functional groups linked to the olefinic carbon atoms, for example, Se-Zr, Se-B, Se-Sn play important roles in organic synthesis, especially in developing a lot of convenient methods for stereoselective synthesis of substituted alkenes4. Recently, Tingoli et al.5 reported that (Z)-a-selanylvinyl p-toluenesulfonates can u…     

Magnetism tuned by intercalation of various metal ions in coordination polymer

Insertion of various metal ions have changed the ferromagnetic coordination frameworks into paramagnetic, superparamagnetic, or ferromagnetic. The net charge and radius of the ions determined the magnetism of the host frameworks.     

Surface carboxyl groups enhance the capacities of carbonaceous oxygen electrodes for aprotic lithium-oxygen batteries: A direct observation on binder-free electrodes

Carbon cloth was proposed as an ideal model to investigate the effect of surface functional groups. The introduction of surface carboxyl groups significantly enhances the capacities of carbonaceous oxygen diffusion electrodes for the lithium-oxygen batteries.     

Catalytic Oxidation of Dimethyl Ether to Hydrocarbons over SnO2/MgO and SnO2/CaO Catalysts

A novel reverse microemulsion method was used to prepare SnO2/MgO and SnO2/CaO catalysts. It was found that both the catalysts were active for the reaction of catalytic oxidation of dimethyl ether (DME) in the temperature range of 275 to 300℃. SnO2/CaO catalyst exhibits much higher activity than SnO2/MgO. On SnO2/CaO catalyst, DME conversion of 21.8% was obtained at 300℃, while selectivities to methyl formate (MF) and dimethoxyethane (DMET) of 19.1% and 59.0% respectively were obtained at 275℃.     

Differentiation of isomeric polyaromatic hydrocarbons by electrospray Ag(I) cationization mass spectrometry

Abundant Ag(I)-cationized complexes of 13 polyaromatic hydrocarbons (PAHs), [Ag+PAH](+) and [Ag+2(PAH)](+), were readily generated by electrospray ionization (ESI). In-source collision-induced dissociation (CID) of the [Ag+2(PAH)](+) complex yielded the monomer complex [Ag+PAH](+), which fragmented further to yield the radical molecular ion [PAH](+.). Based on significant differences in relative intensities of [Ag+2(PAH)](+), [Ag+PAH](+) and [PAH](+.), isomeric PAHs can be differentiated. The [PAH](+.)/[Ag+PAH](+) ion intensity ratio was found to increase with decreasing ionization potentials (IPs) of PAHs. The ratio was significantly different for the isomeric PAHs studied over a wide range of PAH concentrations (1.6-100 nmol/mL), and showed good measurement reproducibility; the coefficient of variation of inter-day measurements was in the range 3-12% for four representative PAHs (n = 5). Detection limits for phenanthrene, pyrene, chrysene and benzo[a]pyrene, in the form of the monomer complexes [(107)Ag+PAH](+) and measured in the selected-ion monitoring (SIM) mode, were 0.31, 0.63, 0.16 and 1.25 pmol/5 microl injection, respectively (S/N ratio approximately 2-3).     

Interfacial Behaviors of Azocalixarene Derivatives at the Air/Water Interface and Photochromism in the Langmuir-Blodgett Films

The azocalixarenes is a novel chromogenic compound and their spectra properties have been reported. A number of them have been applied as selective ionophores in extractive process1 or as selective ligands in ion selective electrodes and optical sensors based on spectra changes2. Some amphiphilic azocalixarene derivatives with hydrophobic long alkyl chains were synthesized and their interfacial behaviors at the air / water interface have also been investigated3. However, the photochromism of t…     

Total Synthesis of Naloxone

Naloxone (1) is one of the 14-hydroxyl substituted opium antagonists which are valuable medications for treat ment of opiate abuse, opiate overdose, and alcohol addiction. Here, the total synthesis of naloxone was described. We selected 2,6-dihydroxynaphalene (2) as the starting material.     

A novel chalcone derivative from Onychium japonicum

A novel chalcone derivative was isolated from Onychium japonicum and its structure was elucidated by spectroscopic methods. The isolated compound showed cytotoxic activity against the human carcinoma cell lines Hela and BEL-7402 in vitro.