Semi-synthesis and Crystal Structure of Sophoridine N-oxide

Sophoridine N-oxide was synthesized and characterized by 1H-NMR,EI-MS,IR and elemental analysis,together with X-ray single-crystal diffraction analysis,and its crystal structure was reported for the first time.The crystal belongs to the orthorhombic system,space group P212121 with a = 8.321（2）,b = 15.650（3）,c = 24.352（5） ,V = 3171.1（11） 3,Z = 8,Dc = 1.258 g/cm3,λ（CuKα） = 1.54178,F（000） = 1440,the final R = 0.0351 and wR = 0.0970.The crystal structure shows Sophoridine N-oxide crystallizes with two host molecules of similar conformation and four water solvent molecules in the asymmetric unit.In the crystal structure,intermolecular O-H…O hydrogen bonds link the constituent molecules into a 2D layer structure,which further extends to a 3D supramolecular architecture via Van der Waals interactions and intermolecular O-H…O hydrogen bonds.

The Evidence for Ferroelectricity on Magnetite Ceramics below the Verwey Transition

We report the temperature-and frequency-dependent dielectric spectrum of magnetite ceramic single phase samples at 77.4–300 K and 200 Hz–1 MHz.In temperature-dependent dc resistivity,the sharp transition expected in single crystals is much suppressed.At higher temperatures,the grain boundaries contribute to the relaxation process.Below 120 K,the temperature-dependent dielectric constant reveals a weak broadened peak as cooling,from our analysis this behavior may be intrinsically correlated with the charge ordering of Fe^(3+) and Fe^(2+).Under a relatively low dc bias at 77.4 K,the polarization of the magnetite ceramic decreases,while under a much stronger electrical field,the dielectric spectrum in the lower frequency region is suppressed remarkably for the excitation of carriers bounded by grain boundaries.

Anticancer Activity of Total Flavonoids Isolated from Xianhe Yanling Recipe(仙鹤延龄方)

Objective：To investigate the anticancer activity of the total flavonoids isolated from a herbal formula,Xianhe Yanling Recipe（仙鹤延龄方）,a recipe commonly used in cancer patients in China.Methods： The in vitro anticancer activity of the total flavonoids was determined using the 3-（4,5-dimethylthiazole-2-yl）-2,5- diphenyltetrazolium bromide（MTT） assay on three cancer cell lines：MCF-7（a human breast adenocarcinoma cell line）,HepG-2（a human hepatocellular carcinoma cell line） and ES-2（a human ovarian cancer cell line）. The in vivo anticancer effect of the total flavonoids was assessed in a mouse tumor model bearing H22-induced hepatocellular carcinoma,and cisplatin was used as a positive control.Results：The total flavonoids exerted a powerful inhibitory effect on the three cell lines,with 50%inhibiting concentrations（IC_（50）） of 24.948,31.569 and 6.923μg/mL,respectively.In vivo studies showed that the total flavonoids had dose-dependent inhibitory effects on hepatocellular carcinoma in mice.Conclusion：The total flavonoids from Xianhe Yanling Recipe have potential anticancer activity,and further researches and development are warranted.

Enhanced catalysis of ultrasmall Au-MoS_2 clusters against reactive oxygen species for radiation protection

Ionizing radiation produces excessive reactive oxygen species(ROS) which impose detrimental effects on biological systems. Thus, it is important to explore clinically safe and efficacious radioprotection agents to scavenge ROS and reduce the risks of radiotherapy. Recently, emerging catalytic nanomaterials such as sulfide nanomaterials have shown capability of clearing ROS in vivo by unique electron transfers between atoms, but their catalytic activities are yet suboptimal. As such, there is an unmet need to improve catalytic properties for stronger antioxidant activities and radiation protection. Herein, we prepared ultrasmall Au-MoS_2 clusters(~2.5 nm) and they showed enhanced catalytic properties via gold intercalation facilitating increased active sites and synergistic effects. Electrocatalysis results revealed that the catalytic activity of Au-MoS_2 towards H2O_2 was superior to ultrasmall MoS_2 without Au. As a result, we found that improving the electrocatalytic property of Au-MoS_2 can effectively enhance corresponding antioxidant activities and radioprotection effects in vivo. In addition, Au-MoS_2 also showed significant radioprotection in vitro and dramatically reduced the excess of radiation-induced adverse ROS. It also rescued radiation-induced DNA damages and protected the bone marrow hematopoietic system from ionizing radiation.

Oxysophoridine Suppresses the Growth of Hepatocellular Carcinoma in Mice:In Vivo and cDNA Microarray Studies

Objective：To observe the in vivo effects of oxysophoridine on hepatocellular carcinoma in mice and to study the related mechanisms.Methods：C57BL mice were inoculated with mouse hepatoma H22 cells subcutaneously,then divided into 5 groups（14 per group）,and treated with oxysophoridine（50,100,or 150 mg/kg） or cisplatin（4 mg/kg） for 10 days.Inhibitory rate of tumor,body weight gain,and influence indices on internal organs（liver,spleen and thymus） were evaluated.The differentially expressed genes between the oxysophoridine-treated group,and the control group were analyzed using cDNA microarray and quantitative real-time PCR（qRT-PCR） experiments.Results：Compared with the tumor weight of the control group（2.75±0.66 g）,oxysophoridine significantly suppressed hepatocellular carcinoma growth in mice（P0.01）,with 0.82±0.36 g,0.57±0.22 g,and 1.22±0.67 g for the tumor weight in the low,moderate,and high dose treatment group, respectively.The moderate dose led to the highest inhibitory rate,79.3%.Observation of body weight gain and influence on three organs showed that compared with cisplatin,oxysophoridine produced fewer side effects in vivo.cDNA microarray and qRT-PCR showed that the most significant differentially expressed genes in the tumor samples of oxysophoridine-treated mice were mostly involved in regulating apoptosis,with the Tnfrsf11b （osteoprotegerin） gene being the most significantly affected.Conclusion：Oxysophoridine was a promising compound for developing drugs against hepatocellular carcinoma,and its anti-hepatoma effect was probably related to osteoprotegerin activation.

Highly efficient catalytic scavenging of oxygen free radicals with graphene-encapsulated metal nanoshields

Normal levels of oxygen free radicals play an important role in cellular signal transduction, redox homeostasis, regulatory pathways, and metabolic processes. However, radiolysis of water induced by high-energy radiation can produce excessive amounts of exogenous oxygen free radicals, which cause severe oxidative damages to all cellular components, disrupt cellular structures and signaling pathways, and eventually lead to death. Herein, we show that hybrid nanoshields based on single-layer graphene encapsulating metal nanoparticles exhibit high catalytic activity in scavenging oxygen superoxide （·O2^-）, hydroxyl （·OH）, and hydroperoxyl （HO2·） free radicals via electron transfer between the single-layer graphene and the metal core, thus achieving biocatalytic scavenging both in vitro and in vivo. The levels of the superoxide enzyme, DNA, and reactive oxygen species measured in vivo dearly show that the nanoshields can efficiently eliminate harmful oxygen free radicals at the cellular level, both in organs and circulating blood. Moreover, the nanoshields lead to an increase in the overall survival rate of gamma ray-irradiated mice to up to 90%, showing the great potential of these systems as protective agents against ionizing radiation.