In this study, we developed a metal-free and highly chemoselective method for the reduction of aromatic nitro compounds. This reduction was performed using tetrahydroxydiboron [B2(OH)4] as the reductant and 4,4′-bipyridine as the organocatalyst and could be completed within 5 min at room temperature. Under optimal conditions, nitroarenes with sensitive functional groups, such as vinyl, ethynyl, carbonyl, and halogen, were converted into the corresponding anilines with excellent selectivity while avoiding the undesirable reduction of the sensitive functional groups.

BackgroundThe beneficial effects of ginsenoside species have been well demonstrated in a number of studies. However, the function of ginsenoside Ro (GRo), an oleanane-type saponin, has not been sufficiently investigated. Thus, the aim of the present study was to investigate the anti-inflammatory effects of GRo in vitro using the Raw 264.7 mouse macrophage cell line treated with lipopolysaccharide (LPS), and to clarify the possible mechanism of GRo involving heme oxygenase-1 (HO-1), which itself plays a critical role in self-defense in the presence of inflammatory stress.MethodsRaw 264.7 cells were pretreated with GRo (up to 200μM) for 1 h before treatment with 1 μg/mL LPS, and both cell viability and inflammatory markers involving HO-1 were evaluated.ResultsGRo significantly increased cell viability in a dose dependent manner following treatment with LPS, and decreased levels of reactive oxygen species and nitric oxide. GRo decreased inflammatory cytokines such as nitric oxide synthase and cyclooxygenase-2 induced by LPS. Moreover, GRo increased the expression of HO-1 in a dose dependent manner. Cotreatment of GRo with tin protoporphyrin IX, a selective inhibitor of HO-1, not only inhibited upregulation of HO-1 induced by GRo, but also reversed the anti-inflammatory effect of GRo in LPS treated Raw 264.7 cells.ConclusionGRo induces anti-inflammatory effects following treatment with LPS via upregulation of HO-1.

Development of a simple, effective, and practical method for (Z)-selective semihydrogenation of alkynes have been considered necessary for easy-to-access applications in organic laboratory scales. Herein, (Z)-selective semihydrogenation of alkynes was...

(Z)-1,8-Di­(pyren-1-yl)­oct-4-ene (1) was prepared as a probe for olefin metathesis. The conversions of substrate by olefin metathesis under various conditions were calculated using the ratiometric fluorescence intensity change of 1. The conversions calculated by 1 and gas chromatography were consistent. These results show that conversions of olefin metathesis can be simply obtained from the fluorescence change of 1 and this method can be applied to the high-throughput screening (HTS) method for various olefin metathesis.