Perilla Leaf Extract Attenuates Asthma Airway Inflammation by Blocking the Syk Pathway.

Perilla frutescens (L.) Britton is a classic herbal plant used widely against asthma in China. But its mechanism of beneficial effect remains undermined. In the study, the antiallergic asthma effects of Perilla leaf extract (PLE) were investigated, and the underlying mechanism was also explored. Results showed that PLE treatment significantly attenuated airway inflammation in OVA-induced asthma mice, by ameliorating lung pathological changes, inhibiting recruitment of inflammatory cells in lung tissues and bronchoalveolar lavage fluid (BALF), decreasing the production of inflammatory cytokines in the BALF, and reducing the level of immunoglobulin in serum. PLE treatment suppressed inflammatory response in antigen-induced rat basophilic leukemia 2H3 (RBL-2H3) cells as well as in OVA-induced human peripheral blood mononuclear cells (PBMCs). Furthermore, PLE markedly inhibited the expression and phosphorylation of Syk, NF-κB, PKC, and cPLA2 both in vivo and in vitro. By cotreating with inhibitors (BAY61-3606, Rottlerin, BAY11-7082, and arachidonyl trifluoromethyl ketone) in vitro, results revealed that PLE's antiallergic inflammatory effects were associated with the inhibition of Syk and its downstream signals NF-κB, PKC, and cPLA2. Collectively, the present results suggested that PLE could attenuate allergic inflammation, and its mechanism might be partly mediated through inhibiting the Syk pathway.

Drastic enhancement of catalytic activity via post-oxidation of a porous MnII triazolate framework.

Mn(III) is a powerful active site for catalytic oxidation of alkyl aromatics, but it can be only stabilized by macrocyclic chelating ligands such porphyrinates. Herein, by using benzobistriazolate as a rigid bridging ligand, a porous Mn(II) azolate framework with a nitrogen-rich coordinated environment similar to that of metalloporphyrins was synthesized, in which the Mn(II) ions can be post-oxidized to Mn(III) to achieve drastic increase of catalytic (aerobic) oxidation performance.

Photoluminescent Metal-Organic Frameworks for Gas Sensing.

Luminescence of porous coordination polymers (PCPs) or metal-organic frameworks (MOFs) is sensitive to the type and concentration of chemical species in the surrounding environment, because these materials combine the advantages of the highly regular porous structures and various luminescence mechanisms, as well as diversified host-guest interactions. In the past few years, luminescent MOFs have attracted more and more attention for chemical sensing of gas-phase analytes, including common gases and vapors of solids/liquids. While liquid-phase and gas-phase luminescence sensing by MOFs share similar mechanisms such as host-guest electron and/or energy transfer, exiplex formation, and guest-perturbing of excited-state energy level and radiation pathways, via various types of host-guest interactions, gas-phase sensing has its unique advantages and challenges, such as easy utilization of encapsulated guest luminophores and difficulty for accurate measurement of the intensity change. This review summarizes recent progresses by using luminescent MOFs as reusable sensing materials for detection of gases and vapors of solids/liquids especially for O2, highlighting various strategies for improving the sensitivity, selectivity, stability, and accuracy, reducing the materials cost, and developing related devices.

Putting an ultrahigh concentration of amine groups into a metal-organic framework for CO2 capture at low pressures.

Tremendous efforts have been devoted to increasing the CO2 capture performance of porous materials, especially for low CO2 concentration environments. Here, we report that hydrazine can be used as a diamine short enough to functionalize the small-pore metal-organic framework [Mg2(dobdc)] (H4dobdc = 2,5-dihydroxyl-1,4-benzenedicarboxylic acid). By virtue of the ultrahigh concentration of free amine groups (6.01 mmol g-1 or 7.08 mmol cm-3) capable of reversible carbamic acid formation, the new material [Mg2(dobdc)(N2H4)1.8] achieves a series of new records for CO2 capture, such as single-component isotherm uptakes of 3.89 mmol g-1 or 4.58 mmol cm-3 at the atmospheric CO2 concentration of 0.4 mbar at 298 K and 1.04 mmol g-1 or 1.22 mmol cm-3 at 328 K, as well as more than a 4.2 mmol g-1 or 4.9 mmol cm-3 adsorption/desorption working capacity under dynamic mixed-gas conditions with CO2 concentrations similar to those in flue gases and ambient air.