No abstract

Hypervalent iodine oxidants have been widely applied in organic reactions due to their low toxicity, ready availability, and ease of handling. We produced an oxidant, [phenyliodine(III)bis(trifluoroethoxide)] (PIFE) by anodic oxidation of iodobenzene, which possesses comparable or superior properties to those of commercially available congeners, such as [phenyliodine(III)bis(trifluoroacetate)] (PIFA) and [phenyliodine(III)diacetate] (PIDA). The availability of PIFE was demonstrated by construction of several nitrogen-containing molecular skeletons; construction of quinolinone derivatives by PIFE occurred smoothly in moderate yield. In addition, the carbazole derivatives were synthesized in higher yields than with use of PIFA. Application of this methodology enabled synthesis of the bioactive tetrahydropyrroloiminoquinone-, carbazole-, and pyrroloindole-class natural products, including makaluvamines, damirones, glycozoline, debromofrustraminol B, and CPC-1.

Oxidative cyclization of N-acetyltryptamine by using iodobenzene diacetate (PIDA) provided the corresponding 1,2,3,3a,8,8a-hexahydropyrrolo[2,3-b]indol-3a-ol derivative, which could be derivatized following appropriate protection of the two amino and tert-hydroxyl groups. The facile one-pot procedure for cyclization and introduction of the oxygen functionality was applied in concise routes for the synthesis of the natural products CPC-1 and debromoflustraminol B.

Highly enantioselective desymmetrization of σ-symmetric 3′-substituted 2′,6′-dimethoxybiphenyl-2,6-diyl diacetate derivatives to the corresponding monoacetates was effected by using Rhizopus oryzae lipase (ROL) and porcine pancreatic lipase (PPL), despite the remoteness of the C(3′) substituent from the acetate groups. ROL promoted hydrolysis of the pro-S acetates, irrespective of the type of C(3′) substituent, whereas PPL promoted hydrolysis of the pro-R acetates, and selectivity was only attainable when the C(3′) substituent was a polar group.

It is known that the consumption of bacteria such as lactobacilli and bifidobacteria has beneficial effects on human immune function. Most of them are Gram-positive bacteria, and there are few reports on Gram-negative bacteria.In this study, we evaluated the effects of intake of Gluconacetobacter hansenii GK-1 (GK-1), Gram-negative acetic acid bacteria, for 12 weeks on physical condition and immune indices. We conducted a randomized, double-blind, placebo-controlled, parallel-group study in 100 healthy adults. The subjects were randomized into the GK-1 and the placebo groups. The diary-administered physical condition survey was conducted during the study period. The evaluation of salivary sIgA levels, NK-cell activity, and serum IFN-γ levels and quality of life survey was conducted before, in 6 weeks, and 12 weeks after the start of ingestion. Based on the physical condition survey, the cumulative onset-days of symptoms were significantly suppressed in the GK-1 group compared to the placebo group regarding the evaluation of 13 symptoms related to immunity, every 3 weeks. Additionally, salivary sIgA levels per hour were significantly increased in the GK-1 group compared with the placebo group at 6 and 12 weeks. Despite no significant differences in the NK-cell activity, serum IFN-γ levels or quality of life survey between the groups. Serum IFN-γ levels in the GK-1 group were significantly elevated at 12 weeks after the start of ingestion compared with those before ingestion. In conclusion, intake of GK-1 was shown to increase salivary sIgA levels and improve physical condition. This suggested that oral intake of GK-1 may help maintain the immune system.