Gene Expression and Metabolome Analysis Reveals Anti-Inflammatory Impacts of 11,17diHDoPE on PM10-Induced Mouse Lung Inflammation.

Oxylipins, the metabolites of polyunsaturated fatty acids, are vital in regulating cell proliferation and inflammation. Among these oxylipins, specialized pro-resolving mediators notably contribute to inflammation resolution. Previously, we showed that the specialized pro-resolving mediators isomer 11,17dihydroxy docosapentaenoic acid (11,17diHDoPE) can be synthesized in bacterial cells and exhibits anti-inflammatory effects in mammalian cells. This study investigates the in vivo impact of 11,17diHDoPE in mice exposed to particulate matter 10 (PM10). Our results indicate that 11,17diHDoPE significantly mitigates PM10-induced lung inflammation in mice, as evidenced by reduced pro-inflammatory cytokines and pulmonary inflammation-related gene expression. Metabolomic analysis reveals that 11,17diHDoPE modulates inflammation-related metabolites such as threonine, 2-keto gluconic acid, butanoic acid, and methyl oleate in lung tissues. In addition, 11,17diHDoPE upregulates the LA-derived oxylipin pathway and downregulates arachidonic acid- and docosahexaenoic acid-derived oxylipin pathways in serum. Correlation analyses between gene expression and metabolite changes suggest that 11,17diHDoPE alleviates inflammation by interfering with macrophage differentiation. These findings underscore the in vivo role of 11,17diHDoPE in reducing pulmonary inflammation, highlighting its potential as a therapeutic agent for respiratory diseases.

Pathway and Production Differences in Branched-Chain Hydroxy Acids as Bioactive Metabolites in Limosilactobacillus fermentum, Ligilactobacillus salivarius, and Latilactobacillus sakei.

Branched-chain hydroxy acids (BCHAs) as bioactive metabolites of Lactobacillaceae include 2-hydroxy isovaleric acid (HIVA), 2-hydroxy isocaproic acid (HICA), and 2-hydroxy-3-methyl isovaleric acid (HMVA). Combining targeted and untargeted metabolomics, this study elucidates differences in extracellular BCHA production in Limosilactobacillus fermentum, Ligilactobacillus salivarius, and Latilactobacillus sakei alongside comparing comprehensive metabolic changes. Through targeted metabolomics, BCHA production among 38 strains exhibited strain specificity, except for L. sakei, which showed significantly lower BCHA production. Explaining the lower production in L. sakei, which lacks the branched-chain amino acid (BCAA)-utilizing pathway, comparison of BCHA production by precursor reaction revealed that the pathway utilizing BCAAs is more dominant than the pathway utilizing pyruvate. Expanding upon the targeted approach, untargeted metabolomics revealed the effects of the reaction compound on other metabolic pathways besides BCHAs. Metabolism alterations induced by BCAA reactions varied among species. Significant differences were observed in glycine, serine, and threonine metabolism, pyruvate metabolism, butanoate metabolism, and galactose metabolism (p < 0.05). These results emphasize the importance of the synergy between fermentation strains and substrates in influencing nutritional components of fermented foods. By uncovering novel aspects of BCAA metabolism pathways, this study could inform the selection of fermentation strains and support the targeted production of BCHAs.

Male castration increases adiposity via small intestinal microbial alterations.

Castration of young males is widely used in the cattle industry to improve meat quality, but the mechanism linking hypogonadism and host metabolism is not clear. Here, we use metataxonomic and metabolomic approaches to evaluate the intestinal microbiota and host metabolism in male, castrated male (CtM), and female cattle. After pubescence, the CtM cattle harbor distinct ileal microbiota dominated by the family Peptostreptococcaceae and exhibit distinct serum and muscle amino acid profiles (i.e., highly abundant branched-chain amino acids), with increased extra- and intramuscular fat storage. We also evaluate the causative factor(s) that underpin the alteration of the intestinal microbiota and host metabolic phenotype in response to hypogonadism. Castration of male mice phenocopies both the intestinal microbial alterations and obese-prone metabolism observed in cattle. Antibiotic treatment and fecal microbiota transplantation experiments in a mouse model confirm that the intestinal microbial alterations associated with hypogonadism are a key contributor to the obese phenotype in the CtM animals. Collectively, targeting the gut microbiota is a potential therapeutic strategy for the treatment of both hypogonadism and obesity.

Antiinflammatory effect of the ethanolic extract of Korean native herb Potentilla rugulosa Nakai in Bisphenol-a-stimulated A549 cells.

Potentilla rugulosa Nakai (P. rugulosa) is a perennial herb in the Rosaceae family and found in the Korean mountains. Previously, our findings demonstrated that P. rugulosa contains numerous polyphenols and flavonoids exhibiting important antioxidant and anti-obesity bioactivities. Bisphenol A (BPA) is a xenoestrogen that was shown to produce pulmonary inflammation in humans. However, the mechanisms underlying BPA-induced inflammation remain to be determined. The aim of this study was to examine whether ethanolic extract of P. rugulosa exerted an inhibitory effect on BPA-induced inflammation utilizing an adenocarcinoma human alveolar basal epithelial cell line A549. The P. rugulosa extract inhibited BPA-mediated cytotoxicity by reducing levels of reactive oxygen species (ROS). Further, P. rugulosa extract suppressed the upregulation of various pro-inflammatory mediators induced by activation of the nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways. In addition, inhibition of the NF-κB and MAPK signaling pathways by P. rugulosa extract was found to occur via decrease in the transcriptional activity of NF-κB. Further, blockade of phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) and stress-activated protein kinase/Jun N-terminal kinase (SAPK/JNK) was noted. Thus, our findings suggest that the ethanolic extract of P. rugulosa may act as a natural anti-inflammatory therapeutic agent.

Strain-specific metabolomic diversity of Lactiplantibacillus plantarum under aerobic and anaerobic conditions.

The chemotaxonomic diversity of 20 Lactiplantibacillus plantarum strains was investigated using non-targeted metabolite profiling under different culture conditions. Multivariate and metabolic pathway analyses based on GC-MS and LC-MS/MS datasets showed that amino acid metabolism, especially 2-hydroxy acids, was enriched under aerobic conditions (AE), whereas fatty acid & sugar metabolism was increased under anaerobic conditions (AN). Based on the metabolite profiles, L. plantarum strains were clustered into three main groups (A, B, and C). Overall, 79 and 83 significantly discriminant metabolites were characterized as chemical markers of AE and AN growth conditions, respectively. Notably, alcohols were more abundant in group A whereas amino acids, peptides, purines, and pyrimidines were significantly higher in group C. 2-hydroxy acids and oxylipins biosynthesized through amino acid and fatty acid metabolism, respectively, were more abundant in groups A and B. Furthermore, we observed a strong correlation between the chemical diversity of L. plantarum groups and their antioxidant activity from metabolite extracts. We propose a non-targeted metabolomic workflow to comprehensively characterize the chemodiversity of L. plantarum strain under different culture conditions, which may help reveal specific biomarkers of individual strains depending on the culture conditions.

PGE1 and PGA1 bind to Nurr1 and activate its transcriptional function.

The orphan nuclear receptor Nurr1 is critical for the development, maintenance and protection of midbrain dopaminergic (mDA) neurons. Here we show that prostaglandin E1 (PGE1) and its dehydrated metabolite, PGA1, directly interact with the ligand-binding domain (LBD) of Nurr1 and stimulate its transcriptional function. We also report the crystallographic structure of Nurr1-LBD bound to PGA1 at 2.05 Å resolution. PGA1 couples covalently to Nurr1-LBD by forming a Michael adduct with Cys566, and induces notable conformational changes, including a 21° shift of the activation function-2 helix (H12) away from the protein core. Furthermore, PGE1/PGA1 exhibit neuroprotective effects in a Nurr1-dependent manner, prominently enhance expression of Nurr1 target genes in mDA neurons and improve motor deficits in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-lesioned mouse models of Parkinson's disease. Based on these results, we propose that PGE1/PGA1 represent native ligands of Nurr1 and can exert neuroprotective effects on mDA neurons, via activation of Nurr1's transcriptional function.

Comprehensive Metabolite Profiling of Four Different Beans Fermented by Aspergillus oryzae.

Fermented bean products are used worldwide; most of the products are made using only a few kinds of beans. However, the metabolite changes and contents in the beans generally used during fermentation are unrevealed. Therefore, we selected four different beans (soybean, Glycine max, GM; wild soybean, Glycine soja, GS; common bean, Phaseolus vulgaris, PV; and hyacinth bean, Lablab purpureus, LP) that are the most widely consumed and fermented with Aspergillus oryzae. Then, metabolome and multivariate statistical analysis were performed to figure out metabolite changes during fermentation. In the four beans, carbohydrates were decreased, but amino acids and fatty acids were increased in the four beans as they fermented. The relative amounts of amino acids were relatively abundant in fermented PV and LP as compared to other beans. In contrast, isoflavone aglycones (e.g., daidzein, glycitein, and genistein) and DDMP-conjugated soyasaponins (e.g., soyasaponins ßa and γg) were increased in GM and GS during fermentation. Notably, these metabolite changes were more significant in GS than GM. In addition, the increase of antioxidant activity in fermented GS was significant compared to other beans. We expect our research provides a basis to extend choice for bean fermentation for consumers and food producers.

Extract of Pinus densiflora needles suppresses acute inflammation by regulating inflammatory mediators in RAW264.7 macrophages and mice.

CONTEXT: Pinus densiflora Siebold & Zucc. (Pinaceae) needle extracts ameliorate oxidative stress, but research into their anti-inflammatory effects is limited. OBJECTIVE: To investigate antioxidant and anti-inflammatory effects of a Pinus densiflora needles (PINE) ethanol extract in vitro and in vivo. MATERIALS AND METHODS: We measured levels of reactive oxygen species (ROS), superoxide dismutase (SOD) and inflammatory mediators in lipopolysaccharide (LPS)-stimulated RAW264.7 cells at various PINE concentrations (25, 50 and 100 µg/mL; but 6.25, 12.5 and 25 µg/mL for interleukin-1ß and prostaglandin E2 (PGE2)). Thirty ICR mice were randomized to six groups: vehicle, control, PINE pre-treatment (0.1, 0.3 and 1 mg/left ear for 10 min followed by arachidonic acid treatment for 30 min) and dexamethasone. The posttreatment ear thickness and myeloperoxidase (MPO) activity were measured. RESULTS: PINE 100 µg/mL significantly decreased ROS (IC50, 70.93 µg/mL, p < 0.01), SOD (IC50, 30.99 µg/mL, p < 0.05), malondialdehyde (p < 0.01), nitric oxide (NO) (IC50, 27.44 µg/mL, p < 0.01) and tumour necrosis factor-alpha (p < 0.05) levels. Interleukin-1ß (p < 0.05) and PGE2 (p < 0.01) release decreased significantly with 25 µg/mL PINE. PINE 1 mg/ear inhibited LPS-stimulated expression of cyclooxygenase-2 and inducible NO synthase in RAW264.7 macrophages and significantly inhibited ear oedema (36.73-15.04% compared to the control, p < 0.01) and MPO activity (167.94-105.59%, p < 0.05). DISCUSSION AND CONCLUSIONS: PINE exerts antioxidant and anti-inflammatory effects by inhibiting the production of inflammatory mediators. Identified flavonoids such as taxifolin and quercetin glucoside can be attributed to effect of PINE.

Integrated genomic and transcriptomic analysis reveals unique mechanisms for high osmotolerance and halotolerance in Hyphopichia yeast.

The yeast species Hyphopichia is common in nature and strongly competitive under harsh environmental conditions. Here, we characterized Hyphopichia burtonii KJJ43 and H. pseudoburtonii KJS14, which exhibit strong halotolerance, using genomic and transcriptomic analyses. The genomes of H. burtonii and H. pseudoburtonii comprised eight chromosomes with 85.17% nucleotide identity and significant divergence in synteny. Notably, both Hyphopichia genomes possessed extended gene families of amino acid permeases and ATP-binding cassette (ABC) transporters, whose dynamic expression patterns during osmotic stress were revealed using transcriptome profiling. Intriguingly, we found unique features of the HOG pathway activated by Hog1p even under non-osmotic stress conditions and the upregulation of cytosolic Gpd1 protein during osmotic stress. Associated with hyperfilamentation growth under high osmotic conditions, a set of genes in the FLO family with induced expression in response to NaCl, KCl, and sorbitol supplementation were identified. Moreover, comparative transcriptome analysis reveals the NaCl-specific induction of genes involved in amino acid biosynthesis and metabolism, particularly BAT2. This suggests the potential association between oxoacid reaction involving branched-chain amino acids and osmotolerance. The combined omics analysis of two Hyphopichia species provides insights into the novel mechanisms involved in salt and osmo-stress tolerance exploited by diverse eukaryotic organisms.

Evaluation of Metabolite Profiles of Ginseng Berry Pomace Obtained after Different Pressure Treatments and Their Correlation with the Antioxidant Activity.

Ginseng berry pomace (GBP) is a byproduct of ginseng berry processing and is rich in numerous bioactive components, including ginsenosides and their derivatives. The application of GBP as a beneficial biomaterial is currently limited. In this study, we aimed to evaluate their potential as a promising source of bioactive compounds using metabolite profiling. The GBP obtained after different ultra-high-pressure (UHP) treatments was analyzed by GC-TOF-MS and UHPLC-LTQ-Orbitrap-MS/MS. In multivariate analyses, we observed a clear demarcation between the control and UHP-treated groups. The results demonstrated that the relative abundance of primary metabolites and a few ginsenosides was higher in the control, whereas UHP treatment contained higher levels of fatty acids and sugars. Furthermore, GBPs were fractionated using different solvents, followed by UHPLC-LTQ-Orbitrap-MS/MS analyses. The heatmap revealed that phenolics (e.g., quercetin, kaempferol) and fewer polar ginsenosides (e.g., F4, Rh2) were abundant in the ethyl acetate fraction, whereas the levels of lignans (e.g., 7-hydroxysecoisolariciresinol, syringaresinol) and fatty acids (e.g., trihydroxy-octadecenoic acid, oxo-dihydroxy-octadecenoic acid) were high in chloroform. Correlation analysis showed that phenolics, less polar ginsenosides, and fatty acids were positively correlated with the antioxidant activity of GBP. Our study highlights GBP as a functional ingredient for the development of high-quality ginseng berry products.

Anti-Gastritis and Anti-Lung Injury Effects of Pine Tree Ethanol Extract Targeting Both NF-κB and AP-1 Pathways.

An ethanol extract (Pd-EE) of Pinus densiflora Siebold and Zucc was derived from the branches of pine trees. According to the Donguibogam, pine resin has the effects of lowering the fever, reducing pain, and killing worms. The purpose of this study is to investigate whether Pd-EE has anti-inflammatory effects. During in vitro trials, NO production, as well as changes in the mRNA levels of inflammation-related genes and the phosphorylation levels of related proteins, were confirmed in RAW264.7 cells activated with lipopolysaccharide depending on the presence or absence of Pd-EE treatment. The activities of transcription factors were checked in HEK293T cells transfected with adapter molecules in the inflammatory pathway. The anti-inflammatory efficacy of Pd-EE was also estimated in vivo with acute gastritis and acute lung injury models. LC-MS analysis was conducted to identify the components of Pd-EE. This extract reduced the production of NO and the mRNA expression levels of iNOS, COX-2, and IL-6 in RAW264.7 cells. In addition, protein expression levels of p50 and p65 and phosphorylation levels of FRA1 were decreased. In the luciferase assay, the activities of NF-κB and AP-1 were lowered. In acute gastritis and acute lung injury models, Pd-EE suppressed inflammation, resulting in alleviated damage.

Exploring the metabolomic diversity of plant species across spatial (leaf and stem) components and phylogenic groups.

BACKGROUND: Plants have been used as an important source of indispensable bioactive compounds in various cosmetics, foods, and medicines. However, the subsequent functional annotation of these compounds seems arduous because of the largely uncharacterized, vast metabolic repertoire of plant species with known biological phenotypes. Hence, a rapid multi-parallel screening and characterization approach is needed for plant functional metabolites. RESULTS: Fifty-one species representing three plant families, namely Asteraceae, Fabaceae, and Rosaceae, were subjected to metabolite profiling using gas chromatography time-of-flight mass spectrometry (GC-TOF-MS) and ultrahigh-performance liquid chromatography quadrupole orbitrap ion trap tandem mass spectrometry (UHPLC-Q-orbitrap-MS/MS) as well as multivariate analyses. Partial least squares discriminant analysis (PLS-DA) of the metabolite profiling datasets indicated a distinct clustered pattern for 51 species depending on plant parts (leaves and stems) and relative phylogeny. Examination of their relative metabolite contents showed that the extracts from Fabaceae plants were abundant in amino acids, fatty acids, and genistein compounds. However, the extracts from Rosaceae had higher levels of catechin and ellagic acid derivatives, whereas those from Asteraceae were higher in kaempferol derivatives and organic acids. Regardless of the different families, aromatic amino acids, branch chain amino acids, chlorogenic acid, flavonoids, and phenylpropanoids related to the shikimate pathway were abundant in leaves. Alternatively, certain amino acids (proline, lysine, and arginine) as well as fatty acids levels were higher in stem extracts. Further, we investigated the associated phenotypes, i.e., antioxidant activities, affected by the observed spatial (leaves and stem) and intra-family metabolomic disparity in the plant extracts. Pearson's correlation analysis indicated that ellagic acid, mannitol, catechin, epicatechin, and quercetin derivatives were positively correlated with antioxidant phenotypes, whereas eriodictyol was positively correlated with tyrosinase inhibition activity. CONCLUSIONS: This work suggests that metabolite profiling, including multi-parallel approaches and integrated bioassays, may help the expeditious characterization of plant-derived metabolites while simultaneously unraveling their chemodiversity.

Physiologic and Metabolic Changes in Crepidiastrum denticulatum According to Different Energy Levels of UV-B Radiation.

Ultraviolet B (UV-B) light, as a physical elicitor, can promote the secondary metabolites biosynthesis in plants. We investigated effects of different energy levels of UV-B radiation on growth and bioactive compounds of Crepidiastrum denticulatum. Three-week-old seedlings were grown in a plant factory for 5 weeks. Plants were subjected to different levels of UV-B (0, 0.1, 0.25, 0.5, 1.0, and 1.25 W m-2), 6 h a day for 6 days. All UV-B treatments had no negative effect on the shoot dry weight; however, relatively high energy treatments (1.0 and 1.25 W m-2) inhibited the shoot fresh weight. UV-B light of 0.1, 0.25, and 0.5 W m-2 did not affect total chlorophyll and H2O2 contents; however, they increased total carotenoid content. On 4 days, 0.25 W m-2 treatment increased antioxidant capacity, total hydroxycinnamic acids (HCAs) content, and several sesquiterpenes. Treatments with 1.0 and 1.25 W m-2 increased total carotenoid, total HCAs, and H2O2 contents, and destroyed chlorophyll pigments, reducing maximum quantum yield of photosystem II and causing visible damage to leaves. Partial least squares discrimination analysis (PLS-DA) showed that secondary metabolites were distinguishably changed according to energy levels of UV-B. The potential of 0.25 W m-2 UV-B for the efficient production of bioactive compounds without growth inhibition in C. denticulatum was identified.

Characterization of Metabolic Changes under Low Mineral Supply (N, K, or Mg) and Supplemental LED Lighting (Red, Blue, or Red-Blue Combination) in Perilla frutescens Using a Metabolomics Approach.

In order to achieve premium quality with crop production, techniques involving the adjustment of nutrient supply and/or supplemental lighting with specific light quality have been applied. To examine the effects of low mineral supply and supplemental lighting, we performed non-targeted metabolite profiling of leaves and stems of the medicinal herb Perilla frutescens, grown under a lower (0.75×) and lowest (0.1×) supply of different minerals (N, K, or Mg) and under supplemental light-emitting diode (LED) lighting (red, blue, or red-blue combination). The lowest N supply increased flavonoids, and the lowest K or Mg slightly increased rosmarinic acid and some flavonoids in the leaves and stems. Supplemental LED lighting conditions (red, blue, or red-blue combination) significantly increased the contents of chlorophyll, most cinnamic acid derivatives, and rosmarinic acid in the leaves. LED lighting with either blue or the red-blue combination increased antioxidant activity compared with the control group without LED supplementation. The present study demonstrates that the cultivation of P. frutescens under low mineral supply and supplemental LED lighting conditions affected metabolic compositions, and we carefully suggest that an adjustment of minerals and light sources could be applied to enhance the levels of targeted metabolites in perilla.

Fathoming Aspergillus oryzae metabolomes in formulated growth matrices.

The stochasticity of Aspergillus oryzae (Trivially: the koji mold) pan-metabolomes commensurate with its ubiquitously distributed landscapes, i.e. growth matrices have been seemed uncharted since its food fermentative systems are mostly being investigated. In this review, we explicitly have discussed the likely tendencies of A. oryzae metabolomes pertaining to its growth milieu formulated with substrate matrices of varying nature, composition, texture, and associated physicochemical parameters. We envisaged typical food matrices, namely, meju, koji, and moromi as the semi-natural cultivation models toward delineating the metabolomic patterns of the koji mold, which synergistically influences the organoleptic and functional properties of the end products. Further, we highlighted how tailored conditions in sub-natural growth matrices, i.e. synthetic cultivation media blends, inducers, and growth surfaces, may influence A. oryzae metabolomes and targeted phenotypes. In general, the sequential or synchronous growth of A. oryzae on formulated matrices results in a number of metabolic tradeoffs with its immediate microenvironment influencing its adaptive and regulatory metabolomes. In broader context, evaluating the metabolic plasticity of A. oryzae relative to the tractable variables in formulated growth matrices might help approximate its growth and metabolism in the more complex natural matrices and environs. These approaches may considerably help in the design and manipulation of hybrid cultivation systems towards the efficient harnessing of commercial molds.

Physiological and Metabolomic Responses of Kale to Combined Chilling and UV-A Treatment.

Short-term abiotic stress treatment before harvest can enhance the quality of horticultural crops cultivated in controlled environments. Here, we investigated the effects of combined chilling and UV-A treatment on the accumulation of phenolic compounds in kale (Brassica oleracea var. acephala). Five-week-old plants were subjected to combined treatments (10 °C plus UV-A LED radiation at 30.3 W/m2) for 3-days, as well as single treatments (4 °C, 10 °C, or UV-A LED radiation). The growth parameters and photosynthetic rates of plants under the combined treatment were similar to those of the control, whereas UV-A treatment alone significantly increased these parameters. Maximum quantum yield (Fv/Fm) decreased and H2O2 increased in response to UV-A and combined treatments, implying that these treatments induced stress in kale. The total phenolic contents after 2- and 3-days of combined treatment and 1-day of recovery were 40%, 60%, and 50% higher than those of the control, respectively, and the phenylalanine ammonia-lyase activity also increased. Principal component analysis suggested that stress type and period determine the changes in secondary metabolites. Three days of combined stress treatment followed by 2-days of recovery increased the contents of quercetin derivatives. Therefore, combined chilling and UV-A treatment could improve the phenolic contents of leafy vegetables such as kale, without growth inhibition.

Integrated Metabolomics and Transcriptomics Unravel the Metabolic Pathway Variations for Different Sized Beech Mushrooms.

Beech mushrooms (Hypsizygus marmoreus) are largely relished for their characteristic earthy flavor, chewy-texture, and gustatory and nutritional properties in East Asian societies. Intriguingly, the aforementioned properties of beech mushroom can be subsumed under its elusive metabolome and subtle transcriptome regulating its various stages of growth and development. Herein, we carried out an integrated metabolomic and transcriptomic profiling for different sized beech mushrooms across spatial components (cap and stipe) to delineate their signature pathways. We observed that metabolite profiles and differentially expressed gene (DEGs) displayed marked synergy for specific signature pathways according to mushroom sizes. Notably, the amino acid, nucleotide, and terpenoid metabolism-related metabolites and genes were more abundant in small-sized mushrooms. On the other hand, the relative levels of carbohydrates and TCA intermediate metabolites as well as corresponding genes were linearly increased with mushroom size. However, the composition of flavor-related metabolites was varying in different sized beech mushrooms. Our study explores the signature pathways associated with growth, development, nutritional, functional and organoleptic properties of different sized beech mushrooms.

Strategy for Screening of Antioxidant Compounds from Two Ulmaceae Species Based on Liquid Chromatography-Mass Spectrometry.

Liquid chromatography-mass spectrometry (LC-MS)-based untargeted metabolomics implies that annotated metabolites can serve as potential markers of the associated bioactivities of plant extracts. Firstly, we selected Aphananthe aspera and Zelkova serrata (Family: Ulmaceae) from 16 Korean plant species based on their distinct principal component analysis (PCA) patterns in LC-MS datasets and antioxidant activity assays. Further, we chose 40% solid-phase extraction (SPE) extracts of the two species displaying the highest antioxidant activities coupled with distinct PCA patterns. Examining the metabolite compositions of the 40% SPE extracts, we observed relatively higher abundances of quercetin, kaempferol, and isorhamnetin O-glucosides for A. aspera, whereas quercetin, isorhamnetin O-glucuronides, and procyanidin dimer were relatively higher in Z. serrata. These metabolites were clearly distinguished in pathway map and displayed strong positive correlations with antioxidant activity. Further, we performed preparative high-performance liquid chromatography (prep-HPLC) analysis coupled with the 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) assay to validate their functional correlations. As a result, quercetin O-sophoroside was determined as the main antioxidant in A. aspera, while isorhamnetin O-glucuronide and procyanidin dimer were the primary antioxidants in Z. serrata. The current study suggests that the LC-MS-based untargeted metabolomics strategy can be used to illuminate subtle metabolic disparities as well as compounds associated with bioactivities.

Cultivar-Specific Changes in Primary and Secondary Metabolites in Pak Choi (Brassica Rapa, Chinensis Group) by Methyl Jasmonate.

Glucosinolates, their hydrolysis products and primary metabolites were analyzed in five pak choi cultivars to determine the effect of methyl jasmonate (MeJA) on metabolite flux from primary metabolites to glucosinolates and their hydrolysis products. Among detected glucosinolates (total 14 glucosinolates; 9 aliphatic, 4 indole and 1 aromatic glucosinolates), indole glucosinolate concentrations (153-229%) and their hydrolysis products increased with MeJA treatment. Changes in the total isothiocyanates by MeJA were associated with epithiospecifier protein activity estimated as nitrile formation. Goitrin, a goitrogenic compound, significantly decreased by MeJA treatment in all cultivars. Changes in glucosinolates, especially aliphatic, significantly differed among cultivars. Primary metabolites including amino acids, organic acids and sugars also changed with MeJA treatment in a cultivar-specific manner. A decreased sugar level suggests that they might be a carbon source for secondary metabolite biosynthesis in MeJA-treated pak choi. The result of the present study suggests that MeJA can be an effective agent to elevate indole glucosinolates and their hydrolysis products and to reduce a goitrogenic compound in pak choi. The total glucosinolate concentration was the highest in "Chinese cabbage" in the control group (32.5 µmol/g DW), but indole glucosinolates increased the greatest in "Asian" when treated with MeJA.

Fumarate-Mediated Persistence of Escherichia coli against Antibiotics.

Bacterial persisters are a small fraction of quiescent cells that survive in the presence of lethal concentrations of antibiotics. They can regrow to give rise to a new population that has the same vulnerability to the antibiotics as did the parental population. Although formation of bacterial persisters in the presence of various antibiotics has been documented, the molecular mechanisms by which these persisters tolerate the antibiotics are still controversial. We found that amplification of the fumarate reductase operon (FRD) inEscherichia coliled to a higher frequency of persister formation. The persister frequency ofE. coliwas increased when the cells contained elevated levels of intracellular fumarate. Genetic perturbations of the electron transport chain (ETC), a metabolite supplementation assay, and even the toxin-antitoxin-relatedhipA7mutation indicated that surplus fumarate markedly elevated theE. colipersister frequency. AnE. colistrain lacking succinate dehydrogenase (SDH), thereby showing a lower intracellular fumarate concentration, was killed ∼1,000-fold more effectively than the wild-type strain in the stationary phase. It appears thatSDHandFRDrepresent a paired system that gives rise to and maintainsE. colipersisters by producing and utilizing fumarate, respectively.