Activity of sEH and Oxidant Status during Systemic Bovine Coliform Mastitis

Bovine coliform mastitis presents treatment challenges because of systemic inflammation and oxidative stress. Soluble epoxide hydrolase (sEH) is a promising therapeutic target in conditions characterized by inflammation and oxidative stress but has not been evaluated in cattle. We compared sEH activity and oxidant status in healthy Holstein dairy cows to those with systemic coliform mastitis (n = 5/group) using complementary approaches. First, the activity of sEH on [3H]-trans-diphenyl-propene oxide (tDPPO) was assessed ex vivo using tissue homogenates (mammary, liver, and kidney). Second, the concentrations of sEH substrates and metabolites in plasma, milk, and urine were determined as an index of in vivo sEH activity. Oxidant status was assessed in serum and milk. Data were analyzed by non-parametric methods. Metabolism of tDPPO was greater in mammary tissues from cows with coliform mastitis compared to controls. In contrast, ratios of sEH substrates and metabolites predicted lower sEH activity in cows with coliform mastitis than controls. Milk oxidant status showed greater prooxidant levels in coliform mastitis cows. Cows with coliform mastitis exhibit increased sEH activity in mammary tissue; at the same time, milk oxidant status is increased. Future studies should characterize sEH activity and oxidant status patterns and explore therapies targeting sEH during coliform mastitis.

A two-step strategy for the selective conversion of ethanol to propene and hydrogen

Simultaneous production of propene and hydrogen from ethanol is the promising way of a renewable feedstock conversion into valuable products. Propene is used for the production of polypropene plastics, acrylonitrile, propene oxide, and many other manufactures; hydrogen is considered the most viable energy carrier for the future. Conventional reaction schemes of the direct one-step catalytic conversion of ethanol into propene include the reaction of the isopropanol dehydration to propene. However, the dehydration ability of a catalyst inevitably gives rise to the ethanol dehydration to ethene that diminishes the propene yield. To avoid ethanol dehydration to ethene, the two-step process is composed of the ethanol conversion to acetone in the first step and the acetone conversion to propene in the second step. The thermodynamic analysis of the known reaction pathways for the ethanol conversion to propene shows that a 74.6% yield of propene can be achieved even at a low temperature of 200oC. According to the literature data, possible catalysts can be Cu/La2Zr2O7 or Fe3O4 for the first step, and the mixed Ag–In/SiO2 and K3PW12O40 catalyst for the second step. We speculate that the propene yield may reach 72% using these catalysts in the two-step process.

Direct epoxidation of propene on silylated Au–Ti catalysts: a study on silylation procedures and the effect on propane formation

Silylation was employed on an active Au/Ti–SiO2 catalyst, in order to enhance catalyst performance for the direct epoxidation of propene to propene oxide (PO) using H2 and O2.

Epoxidation of propene using Au/TiO2: on the difference between H2 and CO as a co-reactant

The role of the reducing gas in the direct epoxidation of propene to propene oxide (PO) using O2 over a Au/TiO2 catalyst was studied through experiments and density functional theory calculations.