Effect of secondary metabolites associated with anaerobic soil conditions on ion fluxes and electrophysiology in barley roots

The effects of secondary metabolites produced by waterlogged soils on net K(+), H(+), and Ca(2+) fluxes were studied in the mature zone of roots of two barley (Hordeum vulgare) cultivars contrasting in their waterlogging (WL) tolerance using the noninvasive microelectrode ion flux measuring technique. In WL-sensitive variety 'Naso Nijo', all three lower monocarboxylic acids (formic, acetic, and propionic acids) and three phenolic acids (benzoic, 2-hydroxybenzoic, 4-hydroxybenzoic acids) caused a substantial shift toward steady K(+) efflux, accompanied by an immediate net influx of H(+). Detrimental effects of secondary metabolites on K(+) homeostasis in root cells were absent in WL-tolerant 'TX' variety. Root treatment with Mn(2+) caused only a temporary K(+) loss that returned to the initial level 10 min after treatment. Phenolic acids slightly increased Ca(2+) influx immediately after treatment, while other metabolites tested resulted in transient Ca(2+) efflux from the root. In the long-term (24 h) treatment, all metabolites tested significantly reduced K(+) uptake and the adverse effects of phenolic acids were smaller than for monocarboxylic acids and Mn(2+). Treatment with monocarboxylic acids for 24 h shifted H(+) from net efflux to net influx, while all three phenolic acids did not cause significant effects compared with the control. Based on results of pharmacological experiments and membrane potential measurements, a model explaining the effects of secondary metabolites on membrane transport activity is proposed. We also suggest that plant tolerance to these secondary metabolites could be considered a useful trait in breeding programs.     

The aldehydic metabolites of linoleic acid are cytotoxic against human breast cancer cells

The cytotoxic effect of aldehydic metabolites of linoleic acid, 13-oxo-tridecadienoic acids, on MCF-7 human breast cancer cells was investigated. The metabolites inhibited the growth of the cancer cells and the effect was dependent on both time of exposure and concentration of the metabolites; 50% growth inhibition occurred at approximately 55 and 33 microM, after 3- and 5-day incubations, respectively. The metabolites had greater cytotoxicity than parent linoleic acid or other polyunsaturated fatty acids tested. The antiproliferative effect was partially reversed by 10 microM of dithiothreitol suggesting that attack on thiol groups in cancer cells by highly reactive alpha, beta-unsaturated carbonyl moiety in the metabolites was responsible for the cytotoxic actions.     

常见肠道菌群代谢产物作为疾病诊断的指针的研究进展

人类肠道菌群能够产生多种代谢产物或与人体相互作用产生肠道菌群-宿主共代谢物,显著影响人体各大系统的生理功能。当人体健康状态以及肠道菌群发生变化时,肠道代谢物的种类和含量也会相应受到影响,因此肠道菌群代谢产物具有作为疾病诊断指针的巨大潜力。本文总结了常见的几类肠道微生物代谢产物,包括糖类、胆碱代谢物、脂质、氨基酸与肽类、维生素、胆汁酸、短链脂肪酸、酚、苯甲酰基和苯基衍生物等,及其在不同疾病状态下的作用机理,以期更好地理解肠道菌群、代谢产物和疾病之间的相关性,为疾病的预防、诊断和治疗提供新的靶点。     

冠突曲霉 veA基因缺失型与野生型的差异代谢物研究

为了鉴定冠突曲霉 veA基因缺失型与野生型的差异代谢物,寻找与 veA 基因产孢相关的代谢物,采用气相色谱-质谱联用（GC-MS）的代谢组学技术,分别收集2个菌株培养48h的菌丝体,经液氮研磨、超声萃取、三甲基氯硅烷衍生化后上机检测,将GC-MS检测的数据进行前处理和代谢物注释,并用统计学相关软件进行差异物筛选和相关性分析。结果显示,共鉴定99种代谢物,其中差异代谢物41种,野生型菌株中表达上调的显著差异代谢物有20种, veA缺失型菌株中表达上调的显著差异代谢物有21种,并预测差异代谢物的相关性,发现与623种代谢物产生相关性,其中313种呈正相关,310种呈负相关。筛选出来的差异代谢物涉及有机酸、氨基酸、碳水化合物、醇类、脂肪酸类等多种代谢物质,其中有机酸和氨基酸类代谢物占主导地位。本研究结果为进一步研究冠突曲霉代谢物与产孢的关联提供了一定的理论基础。     

Metabolomics Analysis of Metabolites in <i>Forsythia suspense</i> Fruit Using UPLC/ESI-Q TRAP-MS/MS

Forsythiae Fructus, the fruit of Forsythia suspense is a traditional Chinese hebal medicine that has the antiviral and antioxidant effects in China. Modern analytical chemistry studies showed that the extracts of Forsythiae Fructus contain many bioactive components, such as flavonoids, lignans, phenolic acids, and terpenoids, which can be used to anti-inflammatory and treat toxicity, tonsillitis, ulcers, pharyngitis and acute nephritis. In order to study the types and quantities of metabolites in Forsythiae Fructus, we isolated, identified and analysed metabolites between two varieties of Forsythiae Fructus using UPLC/ESI-Q TRAP-MS/MS. The results showed that a total of 407 metabolites were identified in Forsythiae Fructus using UPLC/ESI-Q TRAP-MS/MS, including 21 terpenoids, 68 phenolic acids, 63 flavonoids, 43 amino acids and derivatives, 22 alkaloids, 55 lipids, 24 lignans and coumarins, 31 nucleotides and derivatives, 29 organic acids, and 51 other metabolites. Among, lignans and coumarins, terpenoids, organic acids, lipids, and phenolic acids were rich in Forsythiae Fructus, which accounted for more than 60% of the total metabolite content. Differential metabolite analysis revealed that 80 metabolites differed significantly between the two types of Forsythiae Fructus. Our results greatly enrich the Forsythiae Fructus phytochemical composition database and provide valuable information for further study of the metabolites of Forsythiae Fructus.     

不饱和脂肪酸参与调控金针菇菌柄伸长的潜在分析

金针菇Flammulina filiformis菌柄是产量构成的重要组成部分,也是评价质量的重要指标。菌盖下方0.6-1.5cm是菌柄的伸长区,其他区段不伸长。为了研究菌柄伸长的调控机制,我们采用液相色谱-串联质谱联用（LC-MS/MS）技术对金针菇菌柄的伸长区、过渡区和非伸长区进行检测,结合层次聚类分析（HCA）、t检验等统计学方法对差异代谢物进行研究,并通过KEGG分析代谢物富集情况。结果显示,共有69种代谢物在伸长区、过渡区和非伸长区呈现梯度差异,其中52种代谢物含量为梯度性降低,17种代谢物为梯度性增加。这些差异代谢物主要归属于脂肪酸、氨基酸、核苷酸、生物碱等,其中脂肪酸及其衍生物占主导地位,尤其是油酸、花生四烯酸和肾上腺酸含量在菌柄伸长区显著高于其他区段。根据金针菇菌柄的代谢物积累特点,推测脂肪酸及其衍生物可能参与调控金针菇菌柄伸长。     

两种光照处理下苦荞芽菜的代谢物分析

以黑暗和光照处理下苦荞（Fagopyrum tataricum（L.）Gaertner）品种‘晋荞2号’种子萌发所得的芽菜为材料,利用气相色谱-质谱联用分析技术,对两种处理下苦荞芽菜代谢产物的差异进行分析。结果显示,两种光照处理下苦荞芽菜的代谢产物差异明显,在芽菜中共检测出383种代谢产物,其中不同光照处理造成了137种代谢产物的显著差异,他们主要集中在氨基酸及其衍生物、糖类及其衍生物、芳香族化合物和脂肪酸等。除氨基酸及其衍生物外,其余绝大多数差异代谢物的含量在光照组芽菜中较高;KEGG代谢通路分析结果表明,差异代谢物富集于136条物质代谢通路。说明光照能够促进苦荞芽菜多数营养代谢物的生成和积累,营养组分较暗培养更为丰富,营养价值更高。     

Impact of Lactobacillus paracasei IMC502 in coculture with traditional starters on volatile and non-volatile metabolite profiles in yogurt

The impact of Lactobacillus paracasei IMC502 co-fermented with traditional starters on metabolites in yogurt was evaluated using metabolomic analysis. Forty-four volatile metabolites were determined using headspace solid phase microextraction and gas chromatography-mass spectrometry, including alcohols, esters, organic acids, carbonyl and sulfur compounds. Acetaldehyde, diacetyl, acetoin, acetone, butanoic and acetic acid were present in yogurts in higher intensity, which are the major volatile metabolites related to yogurt flavor. L. paracasei IMC502 did not affect the amounts of acetaldehyde, diacetyl and acetoin while promoted the formation of acetone and butanoic acid. A total of 196 non-volatile metabolites including nucleosides, amino acids, carbohydrates, lipids were analyzed using UPLC-Q-TOF-MS. Non-volatile metabolite profiles of these two types of yogurts were distinguished and 94 differential metabolites were screened using multivariate statistical analysis, which were mainly associated with the biosynthesis of secondary metabolites, amino acid metabolism and nucleotide metabolism. The impact of storage on metabolites was also investigated. The amounts of the majority of carbonyl compounds, organic acids and free amino acids increased, while those of acetaldehyde, diacetyl and lactose decreased during storage. This study provides insights into the metabolic mechanism of L. paracasei and represents a real advance in the study of the metabolites in yogurt.     

肠道微生物代谢物在肝硬化中的作用

肝硬化是由多因素引起的终末期肝病,也是导致慢性肝病患者病死的主要原因之一。随着微生物相关多组学的发展和应用,越来越多的研究发现,肠道微生物及其代谢产物如短链脂肪酸、胆汁酸和内毒素等在肝硬化等肝脏疾病中发挥主要作用,但这些肠道微生物代谢产物影响肝硬化发展的机制依然不明确。因此,根据近年来关于肠道微生物及其代谢产物与肝硬化关系的研究,本文重点介绍几种研究比较深入的微生物代谢物以及其影响肝硬化发展的潜在的作用机制,并简要介绍微生物代谢物治疗肝硬化的方法,以期为肝硬化的病理生理学机制、诊断和治疗提供新的见解。

     

Corticosteroid side-chain oxidations--I. Structural effects on the excreted isotope ratios of 4-14C- and 21-3H-labelled corticosteroid metabolites in rabbit urine

The metabolic fates of 4-14C- and 21-3H-labelled corticosteroids have been investigated in the rabbit by analysis of the normalized isotope ratios of neutral and acidic metabolites excreted in the urine. Isotope ratios of excreted radioactivity declined in the order cortisol (F) greater than corticosterone (B) greater than 11-desoxycortisol (S) greater than deoxycorticosterone (DOC). Steroid acids, isolated in alumina fraction C, represented 19.0, 15.0, 9.7 and 2.7% of the doses of DOC, B, S and F, respectively, and the isotope ratios declined in the order F greater than B greater than S greater than DOC. HPLC of steroid acid methyl ester derivatives indicated generally low isotope ratios for DOC and S steroid acids, consistent with complete side-chain oxidation to 20-oxo-21-oic acids and/or 17-carboxylic acids. Several B metabolite methyl esters peaks also exhibited low isotope ratios, but both B and F metabolites gave methyl esters that retained significant tritium consistent with the presence of 20-hydroxysteroid acids. The 21-hydroxy-steroid metabolite fractions had isotope ratios of F = S greater than B greater than DOC. HPLC showed that 20-oxo (tetrahydro) metabolites of B and F had reduced isotope ratios unlike the C-20 reduced (hexahydro) metabolites of DOC and S. It may be concluded that the metabolic fate of the corticoid side-chain in the rabbit is dependent on the steroid structure and may result in the excretion of both 20-oxo and 20-hydroxysteroid acids.     

Regulatory functions of bacterial exometabolites

This review deals with the issue of growth autoregulation and survival in bacterial cultures under starvation conditions. Based on our results and on published data, the conclusion has been drawn that low-molecular products of metabolism (carboxylic acids, amino acids, and other metabolites) perform regulatory functions. The same compounds also control the ecological relationship between microorganisms at the interspecific level, and affect their antagonistic activity. It is suggested that complexes of bacterial metabolites can be used for controlling the composition of various microbiocenosis, including those of humans.     

Direct and indirect effects of microbiota-derived metabolites on neuroinflammation in multiple sclerosis

Multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE) are highly influenced by changes in the microbiota and of microbiota-derived metabolites, including short chain fatty acids, bile acids, and tryptophan derivatives. This review will discuss the effects of microbiota-derived metabolites on neuroinflammation driven by central nervous system-resident cells and peripheral immune cells, and their influence on outcomes of EAE and MS.     

Metabolomic analysis of livers and serum from high-fat diet induced obese mice

Liver and serum metabolites of obese and lean mice fed on high fat or normal diets were analyzed using ultraperformance liquid chromatography-quadrupole-time-of-flight mass spectrometry, gas chromatography-mass spectrometry, and partial least-squares-discriminant analysis (PLS-DA). Obese and lean groups were clearly discriminated from each other on PLS-DA score plot and major metabolites contributing to the discrimination were assigned as lipid metabolites (fatty acids, phosphatidylcholines (PCs), and lysophosphatidylcholines (lysoPCs)), lipid metabolism intermediates (betaine, carnitine, and acylcarnitines), amino acids, acidic compounds, monosaccharides, and serotonin. A high-fat diet increased lipid metabolites but decreased lipid metabolism intermediates and the NAD/NADH ratio, indicating that abnormal lipid and energy metabolism induced by a high-fat diet resulted in fat accumulation via decreased β-oxidation. In addition, this study revealed that the levels of many metabolites, including serotonin, betaine, pipecolic acid, and uric acid, were positively or negatively related to obesity-associated diseases. On the basis of these metabolites, we proposed a metabolic pathway related to high-fat diet-induced obesity. These metabolites can be used to better understand obesity and related diseases induced by a hyperlipidic diet. Furthermore, the level changes of these metabolites can be used to assess the risk of obesity and the therapeutic effect of obesity management.     

基于广泛靶向代谢组学分析黑老虎不同部位成分差异

为提高黑老虎(Kadsura coccinea)资源的综合利用率，采用广泛靶向代谢组学技术鉴定并分析了根、茎、叶代谢组分差异及高度富集成分。结果表明，在根、茎和叶中分别鉴定出642、650和619个代谢物，以酚酸、脂质、类黄酮和有机酸为主；叶与根、茎与根的共有成分分别为566和650个，显著差异成分有442和393个，主要为酚酸、类黄酮和脂质，差异代谢物在苯丙烷生物合成、黄酮与黄酮醇生物合成通路中显著富集。代谢物总丰度和次生代谢物丰度均表现为叶>根>茎，叶中酚酸、类黄酮和脂质及茎中酚酸积累量显著高于根，而氨基酸及其衍生物、萜类、木脂素、香豆素、生物碱的丰度在根中显著上调。因此，黑老虎根、茎、叶有大量共有成分，叶和茎中酚酸、叶中类黄酮和脂质高度富集，含有新绿原酸、绿原酸、槲皮素等多个丰度较高且具有重要生物活性化合物，具有较高利用价值。     

基于UPLC-MS/MS技术的代谢组学方法研究麸皮对杨树桑黄代谢的影响

桑黄孔菌属.Sanghuangporus是一类具有重要药用价值的大型真菌,目前被国际公认为抗肿瘤效果最好的药用真菌之一.本研究以添加麸皮栽培的杨树桑黄Sanghuangporus vaninii子实体为研究对象,基于液质联用技术的广泛靶向代谢组学研究,从杨树桑黄子实体中检测出355种代谢产物,差异代谢物86种,上调51...     

Effects of amino acids and ethanolamine on choline uptake and phosphatidylcholine biosynthesis in baby hamster kidney-21 cells.

The effects of amino acids and ethanolamine on choline uptake and phosphatidylcholine biosynthesis in baby hamster kidney (BHK-21) cells were investigated. The cells were incubated with labelled choline in the presence of an amino acid or ethanolamine. The uptake of labelled choline was noncompetitively inhibited by amino acids. Glycine, L-alanine, L-serine, L-leucine, L-aspartate, and L-arginine were effective inhibitors and a maximum of 22% inhibition of choline uptake was obtained with 5 mM glycine. Analyses of the labelings in the choline-containing metabolites revealed that the conversion of choline to CDP-choline and subsequently phosphatidylcholine was not affected by the presence of amino acids. The uptake of choline was also inhibited by ethanolamine in a concentration-dependent manner. Kinetic studies on the uptake of choline indicated that the inhibition by ethanolamine was competitive in nature. Although ethanolamine is a potent inhibitor of choline kinase, analyses of the labelings in the choline-containing metabolites indicated that the conversion of choline to phosphocholine was not affected in the cells incubated with ethanolamine. Ethanolamine did not change the pool sizes of phosphocholine and CDP-choline. Based on the specific radioactivity of CDP-choline and the labeling of phosphatidylcholine, the rates of phosphatidylcholine biosynthesis were not significantly different between the control and the ethanolamine-treated cells. In view of the concentrations of amino acids (millimolar) and ethanolamine (micromolar) in most cell culture media, it appeared that only amino acids were important metabolites for the regulation of choline uptake in BHK-21 cells. We conclude that both amino acids and ethanolamine have no direct effect on the biosynthesis of phosphatidylcholine.     

广叶绣球菌不同生长阶段栽培基质中代谢物差异分析

【背景】栽培基质的利用是广叶绣球菌(Sparassis latifolia)栽培中重要的生理过程，但栽培过程中基质代谢物的变化尚不清楚。【目的】通过不同生长阶段栽培基质中差异代谢物分析挖掘关键代谢物，为广叶绣球菌基质利用机理研究提供理论参考。【方法】利用UHPLC-MS/MS技术分析广叶绣球菌菌丝(Myc)、原基(Pri)和子实体(FB)生长阶段栽培基质中代谢产物的变化，通过不同数据库进行代谢物注释并进行KEGG通路富集分析。利用LC-MS/MS技术检测不同发育阶段绣球菌中植物类激素含量。【结果】三个不同栽培阶段基质中共鉴定出代谢产物1 360个。不同比较组(Pri vs. Myc、FB vs. Myc和FB vs. Pri)间共有的差异代谢产物179个，含量最高的50个代谢物主要包括氨基酸、脂质、吡喃酸、吡喃酮和植物类激素等物质。其中氨基酸含量在Myc、Pri和FB阶段基质中逐渐降低，而吡喃酸和吡喃酮类化合物含量逐渐升高。植物类激素中的赤霉素在Pri和FB阶段基质中含量较高，茉莉酸在Myc阶段基质中含量较高。对不同发育阶段绣球菌植物类激素进行检测，发现赤霉素GA7仅在原基中检测到，1...     

Metabolic products of arachidonic acid in rats

The pattern of eicosanoid metabolites appearing in urine and feces following oral administration of radioactive arachidonic acid was investigated using rats deficient in essential fatty acids. About 70-80% of the radioactivity in the urine during the first day after feeding was adsorbed to XAD-2 resin and represented eicosanoid metabolites, whereas the rest of the radioactivity was mainly 3H2O. The eicosanoid metabolites were fractionated into different polarity classes using reverse phase Sep-Pak C18 cartridges. Gas chromatographic analysis of the urinary metabolites following their derivatization into methyl ester-methoxime-tert-butyl-dimethylsilyl ethers revealed that nearly one-half of the metabolites had ECL values less than 22 and represented metabolites more oxidized than commonly described. Only 30% of the metabolites had ECL values between 26 to 32, corresponding to the values for the metabolites that originate from exogenously infused prostaglandins. A large portion of the eicosanoid metabolites was also excreted with the feces. The isotopic patterns from the reverse phase chromatography indicated that many of the fecal metabolites may be similar to those in urine although some metabolites in feces were not present in urine. Based on the specific radioactivity of the administered arachidonic acid, it appeared that at least 6 to 8 mg of eicosanoid metabolites were excreted through urine and feces within 24 hrs following an oral bolus of 60 mg arachidonic acid. The rapid increase and subsequent decrease in eicosanoid metabolite excretion after oral administration of arachidonate indicates that the dietary intake of polyunsaturated fatty acids may have a more rapid effect upon the endogenous production of eicosanoids than is generally recognized.