[Two new benzoyl-sesquiterpenes from Mesona chinensis].

Mesona chinensis is a common medicinal and edible plant in the Lingnan region of China, which has extensive pharmacological activity. However, the study of its chemical constituents is not sufficient. In this study, a variety of modern chromatographic separation techniques were used to isolate two compounds from 95% ethanol extract of the grass parts of M. chinensis. Their absolute configurations were determined by ultraviolet spectroscopy(UV), infrared spectroscopy(IR), high resolution mass spectrometry(HR-ESI-MS), 1D and 2D nuclear magnetic resonance(1D NMR and 2D NMR), and single-crystal X-ray diffraction(SC-XRD). Specifically, they were two new benzoyl-sesquiterpenes and named mesonanol A and mesonanol B, respectively. The results of the pharmacological activity evaluation showed that neither of the two new compounds showed obvious antiviral and anti-inflammatory activities.

Molecular Simulation Studies on the Interactions of Bilirubin at Different States with a Lipid Bilayer.

The unconjugated bilirubin (BR) may penetrate through the cell membrane and cause a severe cytotoxicity. However, the molecular mechanism underlying the penetration of BR into the cell membrane is still largely unknown. In this work, we systematically investigate the interaction of BR and a lipid bilayer under different conditions by using all-atom molecular dynamics simulations. It is found that BR at the Z,Z conformation can easily enter into the interior of the lipid bilayer due to its hydrophobicity. However, when BR transforms from the Z,Z conformation to the E,E conformation (after the blue-light emission), its penetration ability is greatly reduced (especially at its ionized state). This study may offer useful physical insights into the effect of phototherapy on the penetration behavior and the cytotoxicity of the unconjugated BR.

Ginsenoside Rg1 protects against H2O2­induced neuronal damage due to inhibition of the NLRP1 inflammasome signalling pathway in hippocampal neurons in vitro.

Oxidative stress and neuroinflammation are important in the pathogenesis of ageing and age­related neurodegenerative diseases, including Alzheimer's disease. NADPH oxidase 2 (NOX2) is a major source of reactive oxygen species (ROS) in the brain. The nucleotide­binding oligomerisation domain (NOD)­like receptor protein 1 (NLRP1) inflammasome is responsible for the formation of pro­inflammatory molecules in neurons. Whether the NOX2­NLRP1 inflammasome signalling pathway is involved in neuronal ageing and age­related damage remains to be elucidated. Ginsenoside Rg1 (Rg1) is a steroidal saponin found in ginseng. In the present study, the primary hippocampal neurons were treated with H2O2 (200 µM) and Rg1 (1, 5 and 10 µM) for 24 h to investigate the protective effects and mechanisms of Rg1 on H2O2­induced hippocampal neuron damage, which mimics age­related damage. The results showed that H2O2 treatment significantly increased ROS production and upregulated the expression of NOX2 and the NLRP1 inflammasome, and led to neuronal senescence and damage to hippocampal neurons. Rg1 decreased ROS production, reducing the expression of NOX2 and the NLRP1 inflammasome in H2O2­treated hippocampal neurons. Furthermore, Rg1 and tempol treatment significantly decreased neuronal apoptosis and the expression of ß­galactosidase, and alleviated the neuronal senescence and damage induced by H2O2. The present study indicates that Rg1 may reduce NOX2­mediated ROS generation, inhibit NLRP1 inflammasome activation, and inhibit neuronal senescence and damage.

[Determination of eight active components in Radix Hedysari by HPLC and its cluster analysis].

An HPLC method was established for the determination of adenosine, γ-aminobutyric acid (GABA) and six flavonoids (calycosin-7-glucoside, ononin, calycosin, isoliquiritigenin, formononetin and medicarpin） in Radix Hedysari. The samples were extracted with methanol by refluxing for 4 h. The HPLC-DAD was performed on a Diamonsil C(18) column (250 mm × 4.6 mm, 5 µm) with acetonitrile-water as the mobile phase. The column temperature was at 40 ℃ and the flow rate was 1.0 m L·min(-1), while the temperature of drift tube was 110.5 ℃ and the nebulizing gas flow was 3.1 L·min-1 for the ELSD system. The results showed all the eight components had good linear relationships (r(2) =0.992 8-1.000 0) in the range of the test concentration. The RSD of precision, stability and repeatability were less than 2%.The average recovery rates were 96.78%-103.45%, and RSD were 0.29%-1.61%.The index component contents of Radix Hedysari form 24 different origins were determined and used as variable factors in clustering analysis. The results were classified into 2 groups basically in accordance with the regional cluster. And the consequence was in consistent with the results of principal component analysis. This HPLC method is simple, shows good sensitive and accurate, and provides the experimental basis for multi-index control of Radix Hedysari. Clustering analysis for Radix Hedysari quality control has a certain reliability and objectivity.

A facile synthesis to Zn(2)SiO(4):Mn(2+) phosphor with controllable size and morphology at low temperature.

Sphere- and rod-shaped Zn(2)SiO(4):Mn(2+) phosphor nanocrystals were synthesized at 230 degrees C. The process consists of tuning the surfactant concentration in the oil/surfactant/ethanol system. Powder X-ray (XRD) and transmission electron microscopy (TEM) were used to characterize the phase purity, size and morphology. Photoluminescent (PL) spectra were collected and analyzed. Fourier transform infrared (FT-IR) spectra of the samples indicate the removal of surfactant in the phosphor nanoparticles. As a result, the sphere-shaped phosphor nanoparticles of 100 nm in size can be redispersed in ethanol ultrasonically. The suspension maintain stable for over 48 h.