Antitumor and immunomodulatory activity of Astragalus membranaceus polysaccharides in H22 tumor-bearing mice.

As a result of a unique synergy between ligand-free Fe/ppm Pd nanoparticles and PEG-containing designer surfactants, a facile and selective reduction of nitro-containing aromatics and heteroaromatics can be effected in water at room temperature in the presence of NaBH4. This new nanotechnology involves low catalyst loadings, is highly chemoselective, and tolerates a wide variety of functional groups. The process, which includes recycling of the entire aqueous medium, offers a general, environmentally responsible, and notably safe approach to highly valued reductions of nitro-containing compounds.

Safe and Selective Nitro Group Reductions Catalyzed by Sustainable and Recyclable Fe/ppm Pd Nanoparticles in Water at Room Temperature

Electron-deficient ruthenium nanoparticles supported on Ru fulleride nanospheres allow the successive and chemoselective hydrogenation of nitrobenzene to aniline and then to cyclohexylamine. The catalysts were prepared in a straightforward manner by decomposition under dihydrogen of [Ru(COD)(COT)] in the presence of C60. The nitrobenzene hydrogenation reaction is solvent sensitive and proceeds more quickly in methanol than in other alcohols. The same behavior, i.e. a two-step successive hydrogenation, has been observed for several substituted nitroarenes. Density functional theory calculations suggest that the observed chemoselectivity is mainly governed by the presence of surface hydrides on the electron-deficient Ru nanoparticles. At the threshold value of 1.5 H per Ru surface atom, the formation of aniline is favored due to the net preference of the NO2 coordination.

Controlled and Chemoselective Hydrogenation of Nitrobenzene over Ru@C60 Catalysts

The concurrent hydrogenation of aromatic and nitro groups poses particular challenges due to the highly differing adsorption strengths of the two chemical moieties on the surfaces of metal catalysts. In a study of the hydrogenation of nitrobenzene as a model reaction, catalysts of ruthenium supported on carbon nanotubes (Ru/CNT) provided an ideal compromise, allowing for hydrogenation of both the aromatic ring and the nitro group. The use of methyl-labeled substrates enabled tracking the pathway of specific substrates and obtaining insight into the relative rates for the hydrogenation of nitrobenzene and intermediates. Together with findings on the coadsorption of nitrobenzene and aniline on the Ru/CNT catalyst, an advanced mechanistic model for the hydrogenation of nitrobenzene emerges.

Concurrent Hydrogenation of Aromatic and Nitro Groups over Carbon-Supported Ruthenium Catalysts

Omega-3 fatty acid-derived mediator, Resolvin E1, ameliorates 2,4-dinitrofluorobenzene-induced atopic dermatitis in NC/Nga mice.

Epicutaneously administered chemical antigens like 2,4-dinitrofluorobenzene (DNFB), evoke an atopic dermatitis (AD)-like dermatitis reaction in NC/Nga mice under specific pathogen free (SPF) conditions. Astragalus membranaceus (AM), is a popular herbal medicine used to treat allergic diseases in East Asia. In the present study, we examined whether AM suppress AD-like skin lesions in NC/Nga mice treated with DNFB under SPF conditions. Oral administration of AM to DNFB-treated NC/Nga mice was found to inhibit ear thickness increases and the skin lesions induced by DNFB. Moreover, IFN-gamma production by CD4(+) T cells from the lymph nodes of DNFB-treated NC/Nga mice was significantly inhibited by AM treatment, although levels of IL-4 and total IgE in serum were not. Study findings suggest that AM may suppress the development of AD-like dermatitis in DNFB-treated NC/Nga mice by reducing IFN-gamma production.

https://bpb.pharm.or.jp/bpb/200708/b08_1468.pdf?origin=publicationDetail

Seung Geun Oh

Papers

Oral administration of Astragalus membranaceus inhibits the development of DNFB-induced dermatitis in NC/Nga mice.

One pot catalytic NO2 reduction, ring hydrogenation, and N-alkylation from nitroarenes to generate alicyclic amines using Ru/C-NaNO2