Dong‐Hyun Kim

The rapid emergence of metabolomics has enabled system-wide measurements of metabolites in various organisms. However, advances in the mechanistic understanding of metabolic networks remain limited, as most metabolomics studies cannot routinely provide accurate metabolite identification, absolute quantification and flux measurement. Stable isotope labeling offers opportunities to overcome these limitations. Here we describe some current approaches to stable isotope-labeled metabolomics and provide examples of the significant impact that these studies have had on our understanding of cellular metabolism. Furthermore, we discuss recently developed software solutions for the analysis of stable isotope-labeled metabolomics data and propose the bioinformatics solutions that will pave the way for the broader application and optimal interpretation of system-scale labeling studies in metabolomics.

The extracts of Coptidis japonica (rhizoma), Eugenia caryophyllata (flower), Rheum palmatum (rhizoma), Magnolia officinalis (cortex) and Rhusjavanica (galla rhois) potently inhibited the growth of Helicobacter pylori (HP). However, these herbal extracts showed no inhibitory effect on HP urease except Galla rhois. Among the components separated from active herbal extracts by silica gel column chromatography, the inhibitory effects of decursinol angelate and decursin on the growth of HP were the most potent, followed by magnolol, berberine, cinnamic acid, decursinol and gallic acid. Minimum inhibitory concentrations (MICs) of decursin and decursinol angelate were 6-20 microg/ml.

Metabolic pathways in <italic>Magnetospirillum gryphiswaldense</italic> MSR-1 are significantly altered under microaerobic (O ₂ -limited) growth conditions enabling magnetosome formation.

Licorice (Glycyrrhiza glabra L., Leguminosae) is frequently used in traditional medicine to treat inflammatory and allergic diseases. In this study, the main components (glycyrrhizin, 18β-glycyrrhetinic acid, isoliquiritin, and liquiritigenin) were isolated from licorice, and their anti-allergic effects, such as antiscratching behavior and IgE production-inhibitory activity, were evaluated both in vitro and in vivo. Liquiritigenin and 18β-glycyrrhetinic acid most potently inhibited the degranulation of RBL-2H3 cells induced by IgE with the antigen (DNP-HSA) and rat peritoneal mast cells induced by compound 48/80. Liquiritigenin and 18β-glycyrrhetinic acid potently inhibited the passive cutaneous anaphylactic reaction as well as the scratching behavior in mice induced by compound 48/80. These components inhibited the production of IgE in ovalbumin-induced asthma mice but liquiritigenin had little effect. This suggests that the antiallergic effects of licorice are mainly due to glycyrrhizin, 18β-glycyrrhetinic acid, and liquiritigenin, which can relieve IgE-induced allergic diseases such as dermatitis and asthma.