Protective effects of parecoxib on rat primary astrocytes from oxidative stress induced by hydrogen peroxide

Objective： To investigate the protective effects of parecoxib from oxidative stress induced by hydrogen peroxide （H202） in rat astrocytes in vitro. Methods： All experiments included 4 groups： （1） negative control （NC） group, without any treatment; （2） H202 treatment group, 100 μmol/L H202 treatment for 24 h; （3） and （4） parecoxib pre- treatment groups, 80 and 160 μmol/L parecoxib treatment for 24 h, respectively, and then treated with 100 μmol/L H202. Several indices were investigated, and the expressions of Bax, Bcl-2, and brain-derived neurotrophic factor （BDNF） were quantified. Results： Compared to the NC group, exposure to H202 resulted in significant morphological changes, which could be reversed by pretreatment of parecoxib. In addition, H202 treatment led to loss of viability （P=0.026） and increased intracellular reactive oxygen species （ROS） levels （P〈0.001）, and induced apoptosis （P〈0.01） in the primary astrocytes relative to the NC group. However, in the parecoxib pretreatment groups, all the above changes reversed significantly （P〈0.05） as compared to the H202 treatment group, and were nearly unchanged when compared to the NC group. Mechanical investigation showed that dysregulated Bax, Bcl-2, and BDNF could be im- plicated in these changes. Conclusions： Our results indicated that parecoxib provided a protective effect from oxidative stress induced by exposure to H202.

Chloride anion-induced dimer capsule based on a polyfluorinated macrocycle meta-WreathArene

[1_n]metacyclophanes are a class of important building blocks for supramolecular assembly of artificial capsules. Herein we present the preparation and properties of a novel polyfluorinated macrocycle metaWreath Arene, a C_(2)-symmetrical [14]metacyclophane. Adopting a cone conformation in acetone solution,the macrocycle can form dimer capsules through hydrogen bonds induced by chloride anions. Each dimer capsule consists of two meta-Wreath Arene and two chloride anions, and has been unambiguously characterized both in solution and in solid state.

Fine-tuning the molecular energy levels by incorporating thiophene units onto the π-backbone of core-expanded naphthalene diimides

A series of core-expanded naphthalene diimides（NDI-DTYM） and thiophene-based derivatives（1a-c）were designed and synthesized to investigate the relationship between molecular structures and the highest occupied molecular orbital（HOMO） energy levels but has little impact on the lowest unoccupied molecular orbital（LUMO） energy levels.The results demonstrated that increasing the number of thiophene units can gradually elevate the HOMO energy levels but had little impact on the LUMO energy levels.The n-channel organic field-effect transistors（OFETs） based on 1b and 1c have demonstrated that these almost unchanged LUMO energy levels are proper to transport electrons.

A self-assembled framework that interpenetrates in crystal but does not interpenetrate in solution

A porous supramolecular framework has been for the first time revealed to undergo interpenetration in crystal and noninterpenetration in solution.A new supramolecular organic framework Bu-SOF has been constructed from the co-assembly of a tetracationic tetrahedral monomer and cucurbit[8]uril(CB[8])in water through the encapsulation of two anti-parallel n-butyl chains by CB[8].X-ray diffraction analysis reveals that Bu-SOF forms 3-fold interpenetrated networks in crystals grown by evaporation of its solution in water.1 H NMR,dynamic light scattering and isothermal titration calorimetric experiments confirm that Bu-SOF is also formed in water.Solid samples,prepared by lyophilizing the aqueous solution of Bu-SOF,can adsorb nanoscaled organic dyes,supporting the porosity of the framework and thus non-interpenetration in solution.The avoidance of interpenetration of Bu-SOF in solution has been attributed to the filling of water inside the porous framework as well as the electrostatic repulsion of the appended bipyridinium units of the tetrahedral building block.