No abstract

This communication shows that it is possible to activate nickel complexes containing the R-iminoenamide ligand using B(C 6 F 5 ) 3 or Al(C 6 F 5 ) 3 to generate catalysts that polymerize ethylene. The polymerization of ethylene using these novel compounds is discussed. The novel activation method is confirmed by the X-ray crystallography studies of the methallyl analogs.

Magnolol, honokiol, and obovatol are well-known bioactive constituents of the bark of Magnolia officinalis and have been used as traditional Chinese medicines for the treatment of neurosis, anxiety, and stroke. We recently isolated novel active compound (named 4-O-methylhonokiol) from the ethanol extract of Magnolia officinalis. The present study aimed to test two different doses of ethanol extracts of Magnolia officinalis (5 and 10 mg/kg/mouse, p.o., 1 week) and 4-O-methylhonokiol (0.75 and 1.5 mg/kg/mouse, p.o., 1 week) administered for 7 days on memory impairment induced by scopolamine (1 mg/kg body weight i.p.) in mice. Memory and learning were evaluated using the Morris water maze and the step-down avoidance test. Both the ethanol extract of Magnolia officinalis and 4-O-methylhonokiol prevented memory impairment induced by scopolamine in a dose-dependent manner. The ethanol extract of Magnolia officinalis and 4-O-methylhonokiol also dose-dependently attenuated the scopolamine-induced increase of acetylcholinesterase (AChE) activity in the cortex and hippocampus of mice, and inhibited AChE activity in vitro with IC50 (12 nM). This study, therefore, suggests that the ethanol extract of Magnolia officinalis and its major ingredient, 4-O-methylhonokiol, may be useful for the prevention of the development or progression of AD.

Levan, a polysaccharide that can be produced by both plants and micro‐organisms, is a sugar polymer composed of fructose, with‐2,6 linkages. Here, we have attempted to assess the possible use of levan produced by Zymomonas mobilis as a cosmeceutical ingredient. In service of this goal, we assessed a host of levan's properties, including its moisturizing effects, cell cytotoxicity, cell proliferation effects and anti‐inflammation effects. Levan exhibited a moisturizing effect that was almost exactly the same as that evidenced by hyaluronic acid, as well as a similar cell proliferation effect in human fibroblast and keratinocyte cell lines. Moreover, in our cell proliferation test, which was conducted using bio‐artificial skin constructed via 3‐dimensional (3‐D) culture after the induction of primary skin inflammation with 0.05% sodium lauryl sulphate (SLS), cell viability in the presence of levan (0.01 and 0.05 mg mL–1) was determined to be higher than cell viability in the absence of levan. In our anti‐inflammation test, which was also conducted using 3‐D artificial skin, and which involved the measurement of a quantity of secreted interleukin‐1 (IL‐1), a pre‐inflammatory mediator induced by SLS, we determined that the quantity of IL‐1 in the 3‐D artificial skin treated with 0.01 and 0.05 mg mL–1 of levan was less than that registered in a skin sample that had been treated only with SLS. In this study, we determined that levan exerted an anti‐inflammatory effect against inflammatory reactions to skin irritants, and also that levan exerted a cell‐proliferative effect in bio‐artificial skin, thereby indicating its potential applicability as a cosmeceutical agent.