Additional Metabolites Research Articles

Exploring genetic links between blood metabolites and gout susceptibility.

Gout, a prevalent form of inflammatory arthritis, has a complex etiology where the causal relationship between metabolites and the disease remains underexplored. This study aims to elucidate the impact of genetically determined blood metabolites on gout. Employing a two-sample bidirectional Mendelian randomization analysis, we examined the association between 1400 blood metabolites and gout. Causal associations were determined using the inverse variance weighted (IVW) method with false discovery rate (FDR) correction. Sensitivity analyses encompassed weighted models, MR-Egger, weighted median, and MR-PRESSO approaches. MR-pleiotropy and Cochran's Q statistic were utilized to evaluate potential heterogeneity and pleiotropy. Additionally, metabolic pathway analyses were conducted to pinpoint relevant pathways. Of the initial 4 serum metabolites identified, 3 known metabolites-hexanoylglutamine levels, mannose content, and the phosphate to mannose ratio-were found to be causally associated with gout, along with 55 serum metabolites identified as potential predictors of gout (PIVW < 0.05). Furthermore, we discovered 3 metabolic pathways implicated in gouty attacks. Our findings, derived from Mendelian randomization, indicate that the identified metabolites and pathways may serve as biomarkers for clinical screening and prevention of gout. Additionally, they offer novel insights into the mechanisms of the disease and potential drug targets. Key points • Conducted a comprehensive Mendelian randomization study involving 1400 blood metabolites to explore their genetic impact on gout development and progression • Identified three key metabolites-hexanoylglutamine, mannose, and the phosphate-to-mannose ratio-with causal associations to gout, highlighting their potential use as biomarkers for early detection and risk stratification • Discovered 55 additional serum metabolites as potential predictors of gout, offering new insights into the pathophysiology of the disease and identifying high-risk individuals • Revealed three novel metabolic pathways involved in gout attacks, providing new therapeutic targets for precision medicine in gout treatment.

Catechol acetylglucose: a newly identified benzoxazinoid-regulated defensive metabolite in maize.

An enormous diversity of specialized metabolites is produced in the plant kingdom, with each individual plant synthesizing thousands of these compounds. Previous research showed that benzoxazinoids, the most abundant class of specialized metabolites in maize, also function as signaling molecules by regulating the production callose as a defense response. We searched for additional benzoxazinoid-regulated specialized metabolites, characterized them, examined whether they too function in herbivore protection, and determined how Spodoptera frugiperda (fall armyworm), a prominent maize pest, copes with these metabolites. We identified catechol acetylglucose (CAG) as a benzoxazinoid-regulated metabolite that is produced from salicylic acid via catechol and catechol glucoside. Genome-wide association studies of CAG abundance identified a gene encoding a predicted acetyltransferase. Knockout of this gene resulted in maize plants that lack CAG and over-accumulate catechol glucoside. Upon tissue disruption, maize plants accumulate catechol, which inhibits S. frugiperda growth. Analysis of caterpillar frass showed that S. frugiperda detoxifies catechol by glycosylation, and the efficiency of catechol glycosylation was correlated with S. frugiperda growth on a catechol-containing diet. Thus, the success of S. frugiperda as an agricultural pest may depend partly on its ability to detoxify catechol, which is produced as a defensive metabolite by maize.

Quantitation and Abundance of Xylazine and Xylazine Metabolites in Human Urine and Plasma by LC-MS/MS

Abstract The most common cause of drug overdose fatality in the US involves synthetic opioids such as fentanyl. Recently the Director of the White House Office of National Drug Control Policy designated fentanyl adulterated or associated with xylazine as an emerging threat to the US, and a national response plan will include xylazine testing. Xylazine is a clonidine analog and is not FDA-approved for use in humans but has been increasingly detected in unregulated illicit drugs supplies. Our understanding of xylazine detection, metabolism, and clinical impact on patients, however, is limited. The objectives of this study are to develop a liquid chromatography tandem mass spectrometry (LC-MS/MS) method to detect xylazine and xylazine metabolites in urine and plasma, and to investigate the presence and abundance of xylazine metabolites in remnant urine and plasma samples submitted for clinical testing. This is achieved by first collecting paired urine and serial plasma samples when urine tests positive for xylazine during routine clinical testing. Plasma samples were prepared for LC-MS/MS analysis by protein precipitation with methanol and xylazine-D6 internal standard. Urines were prepared by dilution with xylazine-D6, followed by a hydrolysis with beta-glucuronidase. All experiments were performed using an Aquity HPLC coupled to a Waters TQS-micro triple quadrupole mass spectrometer. LC separation utilized a C18 column with a 4-minute gradient from 2% to 98% mobile phase B (0.1% formic acid and 2mM ammonium acetate in A: water; B: methanol) with a flow rate of 400 μl/min at 50°C. Multiple reaction monitoring for xylazine and 4-OH-xylazine was optimized with commercial standards. Calibration curves for both analytes were prepared from 0.5 – 2,000 ng/mL in plasma, and 5 – 5,000 ng/mL in urine. Product ion scanning was used to detect four additional xylazine metabolites by spectral matching with previously published full scan tandem mass spectra. The highest intensity fragment ions observed in the product ion spectra were used to develop multiple reaction monitoring experiments for four additional xylazine metabolites, previously described as: sulfone-xylazine, oxo-xylazine, OH-sulfone-xylazine, and OH-oxo-xylazine, in 50 remnant urines and 70 individual plasmas. In remnant urines, xylazine concentrations ranged from less than 5 to greater than 5,000 ng/mL. In remnant plasmas, xylazine ranged from less than 0.5 to 158 ng/mL. Previously reported xylazine metabolites were detected in both urine and plasma, and relative peak area ratios were calculated as metabolite-to-xylazine in both matrices. In urine, the highest average peak area ratio (3.1) was observed for sulfone xylazine, after hydrolysis. In plasma, the highest average peak area ratio (1.4) was observed for oxo-xylazine. We were unable to absolutely quantitate either metabolite due to lack of available standards. Future studies include investigation on the association of xylazine exposure and plasma concentrations with clinical presentation and patient outcomes.

Bioprospecting of novel and biologically active compounds and enzymes from a new fungal biobank for industrial biotechnology

Here, we present methods for screening any newly isolated microbial biobank for enzymes, antioxidants, and additional secondary metabolites. Bioactive compounds and enzymes produced by fungi have many applications in industry as valuable leads for pharmaceuticals, nutraceuticals, and potential strains for industrial biotechnology. In this study, fungi collected from Irish habitats were purified and identified by sequencing Internal Transcribed Spacer (ITS) ribosomal DNA regions. Reducing sugars released because of enzyme hydrolysis was used to estimate the relative enzyme activity for carboxymethyl cellulase, pectinase, β-xylanase, arabinoxylanase, mannanase, and galacto-mannanase in the fungal extracts and was normalized against the crude protein content to express relative enzyme activity/milligram. The best enzyme producers were as follows: F1 Clonostachys rosea demonstrated 351.63 U/mg β-xylanase and 645.50 U/mg arabinoxylanase activity; F2 Penicillium expansum had 25 U/mg cellulase and 112.5 U/mg pectinase activity; F3 Fusarium avenaceum had 139.36 U/mg arabinoxylanase, 52.33 U/mg galacto-mannanase, and 45 U/mg mannanase activity; and F9 Trichoderma koningii had 372.15 U/mg β-xylanase and 655.18 U/mg arabinoxylanase activity. In addition to enzyme activity, these strains also exhibited antioxidant activity when tested in Oxygen radical absorbance capacity (ORAC), 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and Ferric ion reducing antioxidant power (FRAP) assays, with activity expressed as μmol Trolox equivalents (TE) per gram of dried fungal extract. In results from the ORAC assay, F1 C. rosea reported 655,669 µmol TE/g; F2 P. expansum had 636,889 µmol TE/g; and F3 F. avenaceum had 4,488,035 µmol TE/g. High DPPH activity was observed for F1 C. rosea at 12,572 µmol TE/g, F3 F. avenaceum at 22,646 µmol TE/g, and F9 T. koningii at 22,558 µmol TE/g. F1 C. rosea, F3: F. avenaceum, and F9 T. koningii also reported high FRAP activity at 36,019 µmol TE/g, 69,325 µmol TE/g, and 25,812 µmol TE/g, respectively. In terms of secondary metabolites, the main compounds detected for the isolates were F1 C. rosea produced benzoic acid, 3-pyridinepropionic acid, and cyclo(-Gly-Phe); F2 P. expansum produced Cyclo(-Gly-Phe) and prenitremone A; F3 F. avenaceum produced cyclo(-Leu-Leu) and p-anisaldehyde; and F9 T. koningii produced cyclo(-Gly-Phe), canescin, citreoviridin X, and cyclopaldic acid. These selected isolates indicate that Irish fungi are a potential source of enzymes and novel biologically active compounds useful in industrial biotechnology and bioproduction supporting sustainability and responsible environmental management.

B-298 Quantitation and Abundance of Xylazine and Xylazine Metabolites in Human Urine by LC-MS/MS

Abstract Background The most common cause of drug overdose fatality in the US involves synthetic opioids such as fentanyl. Recently the Director of the White House Office of National Drug Control Policy designated fentanyl associated with xylazine as an emerging threat to the US, and a national response plan will include xylazine testing. Xylazine, a clonidine analog is not FDA-approved for use in humans but has been increasingly detected in unregulated illicit drugs supplies. Our understanding of xylazine detection, metabolism, and clinical impact on patients, however, is limited. The objectives of this study are to develop a liquid chromatography tandem mass spectrometry (LC-MS/MS) method to investigate the presence and abundance of xylazine metabolites in remnant urine samples submitted for clinical testing. Methods Remnant urine samples were identified when tested positive for xylazine during routine clinical LC-MS/MS testing. All experiments were performed using an Acquity HPLC coupled to a Waters TQS-micro triple quadrupole mass spectrometer. Urines were diluted with xylazine-D6 internal standard, hydrolyzed using β-glucuronidase and separated on a 100mm x 2.1mm, 2.6μm Kinetex C18 column (Phenomenex) with a 4 minute step gradient from 2% to 98% mobile phase B (0.1% formic acid and 2mM ammonium acetate in A: water; B: methanol) with a flow rate of 400 μl/min at 50°C. Xylazine and 4-OH-xylazine were detected in positive mode using multiple reaction monitoring, with transitions optimized from standards (Cayman Chemical and/or Sigma Aldrich), resulting in the following transitions: xylazine: 221&amp;gt;90, 221&amp;gt;164; 4-OH xylazine: 237&amp;gt;90, 237&amp;gt;137. Xylazine and 4-OH-xylazine were quantified using calibration curves prepared from 1 - 5,000 ng/mL in negative urine. Product ion scanning (PIS) was used to detect four additional xylazine metabolites, based on spectral matching to previously published full scan high resolution product ion spectra. The highest abundance fragment ions and identified retention times from PIS experiments were used to perform targeted detection for sulfone-xylazine (253&amp;gt;181, 253&amp;gt;147), oxo-xylazine (235&amp;gt;122, 235&amp;gt;114), OH-sulfone-xylazine (269&amp;gt;197, 269&amp;gt;163), and OH-oxo-xylazine (251&amp;gt;197, 251&amp;gt;148). Results Xylazine was detected at &amp;gt;=1 ng/mL in 38% (54/138) of fentanyl positive urines. A subset (n= 362) of urines that screened positive for opiates, amphetamines, or cocaine metabolite, were also tested but xylazine was detected in only 1 urine that did not contain fentanyl.Xylazine concentrations quantified in 61 remnant urines ranged from &amp;lt;1 to &amp;gt;5,000 ng/mL. 4-OH-xylazine concentrations ranged from &amp;lt;1 to 509 ng/mL. We observed five previously reported xylazine metabolites: 4-OH-xylazine, oxo-xylazine, sulfone-xylazine, OH-oxo-xylazine, OH-sulfone-xylazine. The mean concentration ratio of 4-OH-xylazine-to-xylazine was 0.11. The mean peak area ratios (metabolite-to-xylazine) for sulfone-xylazine, OH-oxo-xylazine, OH-sulfone-xylazine, and oxo-xylazine were 3.5, 3.8, 2.1, and &amp;lt;0.1, respectively. The proposed sulfone-xylazine and OH-oxo-xylazine metabolites were observed to have the most abundant signal of all detected metabolites, although there is currently no commercially available standard to facilitate quantification. Conclusions Xylazine and 4-OH-xylazine were quantitated in 61 patient urines. Four additional xylazine metabolites were observed and relative abundance to xylazine was estimated using peak areas. Future studies include quantitation of xylazine and xylazine metabolites in plasma and association of xylazine detection with clinical presentation and patient outcomes.

The evolution of plant responses underlying specialized metabolism in host-pathogen interactions.

In the course of plant evolution from aquatic to terrestrial environments, land plants (embryophytes) acquired a diverse array of specialized metabolites, including phenylpropanoids, flavonoids and cuticle components, enabling adaptation to various environmental stresses. While embryophytes and their closest algal relatives share candidate enzymes responsible for producing some of these compounds, the complete genetic network for their biosynthesis emerged in embryophytes. In this review, we analysed genomic data from chlorophytes, charophytes and embryophytes to identify genes related to phenylpropanoid, flavonoid and cuticle biosynthesis. By integrating published research, transcriptomic data and metabolite studies, we provide a comprehensive overview on how these specialized metabolic pathways have contributed to plant defence responses to pathogens in non-vascular bryophytes and vascular plants throughout evolution. The evidence suggests that these biosynthetic pathways have provided land plants with a repertoire of conserved and lineage-specific compounds, which have shaped immunity against invading pathogens. The discovery of additional enzymes and metabolites involved in bryophyte responses to pathogen infection will provide evolutionary insights into these versatile pathways and their impact on environmental terrestrial challenges.This article is part of the theme issue 'The evolution of plant metabolism'.

Urine metabolomic profiles of autism and autistic traits-A twin study.

Currently, there are no reliable biomarkers for autism diagnosis. The heterogeneity of autism and several co-occurring conditions are key challenges to establishing these. Here, we used untargeted mass spectrometry-based urine metabolomics to investigate metabolic differences for autism diagnosis and autistic traits in a well-characterized twin cohort (N = 105). We identified 208 metabolites in the urine samples of the twins. No clear, significant metabolic drivers for autism diagnosis were detected when controlling for other neurodevelopmental conditions. However, we identified nominally significant changes for several metabolites. For instance, phenylpyruvate (p = 0.019) and taurine (p = 0.032) were elevated in the autism group, while carnitine (p = 0.047) was reduced. We furthermore accounted for the shared factors, such as genetics within the twin pairs, and report additional metabolite differences. Based on the nominally significant metabolites for autism diagnosis, the arginine and proline metabolism pathway (p = 0.024) was enriched. We also investigated the association between quantitative autistic traits, as measured by the Social Responsiveness Scale 2nd Edition, and metabolite differences, identifying a greater number of nominally significant metabolites and pathways. A significant positive association between indole-3-acetate and autistic traits was observed within the twin pairs (adjusted p = 0.031). The utility of urine biomarkers in autism, therefore, remains unclear, with mixed findings from different study populations.

Lactate promotes the biofilm-to-invasive-planktonic transition in Salmonella enterica serovar Typhimurium via the de novo purine pathway.

Salmonella enterica serovar Typhimurium (S. Typhimurium) infection triggers an inflammatory response that changes the concentration of metabolites in the gut impacting the luminal environment. Some of these environmental adjustments are conducive to S. Typhimurium growth, such as the increased concentrations of nitrate and tetrathionate or the reduced levels of Clostridia-produced butyrate. We recently demonstrated that S. Typhimurium can form biofilms within the host environment and respond to nitrate as a signaling molecule, enabling it to transition between sessile and planktonic states. To investigate whether S. Typhimurium utilizes additional metabolites to regulate its behavior, our study delved into the impact of inflammatory metabolites on biofilm formation. The results revealed that lactate, the most prevalent metabolite in the inflammatory environment, impedes biofilm development by reducing intracellular c-di-GMP levels, suppressing the expression of curli and cellulose, and increasing the expression of flagellar genes. A transcriptomic analysis determined that the expression of the de novo purine pathway increases during high lactate conditions, and a transposon mutagenesis genetic screen identified that PurA and PurG, in particular, play a significant role in the inhibition of curli expression and biofilm formation. Lactate also increases the transcription of the type III secretion system genes involved in tissue invasion. Finally, we show that the pyruvate-modulated two-component system BtsSR is activated in the presence of high lactate, which suggests that lactate-derived pyruvate activates BtsSR system after being exported from the cytosol. All these findings propose that lactate is an important inflammatory metabolite used by S. Typhimurium to transition from a biofilm to a motile state and fine-tune its virulence.IMPORTANCEWhen colonizing the gut, Salmonella enterica serovar Typhimurium (S. Typhimurium) adopts a dynamic lifestyle that alternates between a virulent planktonic state and a multicellular biofilm state. The coexistence of biofilm formers and planktonic S. Typhimurium in the gut suggests the presence of regulatory mechanisms that control planktonic-to-sessile transition. The signals triggering the transition of S. Typhimurium between these two lifestyles are not fully explored. In this work, we demonstrated that in the presence of lactate, the most dominant host-derived metabolite in the inflamed gut, there is a reduction of c-di-GMP in S. Typhimurium, which subsequently inhibits biofilm formation and induces the expression of its invasion machinery, motility genes, and de novo purine metabolic pathway genes. Furthermore, high levels of lactate activate the BtsSR two-component system. Collectively, this work presents new insights toward the comprehension of host metabolism and gut microenvironment roles in the regulation of S. Typhimurium biology during infection.

Using umbilical cord tissue to identify prenatal ethanol exposure and co-exposure to other commonly misused substances.

Substance misuse during pregnancy can result in a variety of poor pregnancy outcomes. Objective data reporting the prevalence of neonates born with ethanol metabolites (evidence of prenatal ethanol exposure) in their fluids or tissues are limited. A secondary analysis of umbilical cord tissue specimens received for routine toxicological analysis was conducted. Prevalences of ethyl glucuronide (EtG), a long-term direct ethanol biomarker, were determined using a new laboratory tool, LDTD-MSMS. Additionally, other commonly misused substances were determined using routine procedures. Of 12,995 specimens, 238 (1.8%) specimens contained EtG. Concentrations of EtG ranged from 5 ng/g to 6679 ng/g (median 47 ng/mg; IQR: 16 ng/g, 203 ng/g). Of those 238 EtG-positive specimens, nearly 58% (N = 138) contained additional substances or metabolites. Self-report of substance use during pregnancy is under-reported. We have demonstrated co-exposure of substances with ethanol is higher than previous reports.

Bioactivation of cinnamic alcohol in a reconstructed human epidermis model and evaluation of sensitizing potency of the identified metabolites.

Cinnamic alcohol is a natural compound, widely used in fragrances, which can cause allergic contact dermatitis. Cinnamic alcohol lacks intrinsic reactivity and autoxidation or metabolic activation is necessary for it to act as a sensitizer. Bioactivation of cinnamic alcohol was explored using human liver microsomes, human liver S9 and SkinEthic™ Reconstructed Human Epidermis. A targeted multiple reaction monitoring mass spectrometry method was employed to study and quantify cinnamic alcohol along with eight potential phase I or phase II metabolites. The reconstructed human epidermis model, treated with cinnamic alcohol, was also analyzed with a non-targeted high-resolution mass spectrometry method to identify metabolites not included in the targeted method. Two metabolites identified with the targeted method, namely, pOH-cinnamic alcohol and pOH-cinnamic aldehyde, have not previously been identified in a metabolic in vitro system. Their reactivity toward biologically relevant nucleophiles was investigated and compared to their sensitizing potency in vivo in the murine local lymph node assay (LLNA). According to the LLNA, the pOH-cinnamic alcohol is non-sensitizing and pOH-cinnamic aldehyde is a moderate sensitizer. This makes pOH-cinnamic aldehyde less sensitizing than cinnamic aldehyde, which has been found to be a strong sensitizer in the LLNA. This difference in sensitizing potency was supported by the reactivity experiments. Cinnamic sulfate, previously proposed as a potential reactive metabolite of cinnamic alcohol, was not detected in any of the incubations. In addition, experiments examining the reactivity of cinnamic sulfate toward a model peptide revealed no evidence of adduct formation. The only additional metabolite that could be identified with the non-targeted method was a dioxolan derivative. Whether or not this metabolite, or one of its precursors, could contribute to the sensitizing potency of cinnamic alcohol would need further investigation. Cinnamic alcohol is one of the most common fragrance allergens and as it is more effective to patch test with the actual sensitizer than with the prohapten itself, it is important to identify metabolites with sensitizing potency. Further, improved knowledge of metabolic transformations occurring in the skin can improve prediction models for safety assessment of skin products.

Integrating functional metagenomics to decipher microbiome-immune interactions.

Microbial metabolites can be viewed as the cytokines of the microbiome, transmitting information about the microbial and metabolic environment of the gut to orchestrate and modulate local and systemic immune responses. Still, many immunology studies focus solely on the taxonomy and community structure of the gut microbiota rather than its functions. Early sequencing-based microbiota profiling approaches relied on PCR amplification of small regions of bacterial and fungal genomes to facilitate identification of the microbes present. However, recent microbiome analysis methods, particularly shotgun metagenomic sequencing, now enable culture-independent profiling of microbiome functions and metabolites in addition to taxonomic characterization. In this review, we showcase recent advances in functional metagenomics methods and applications and discuss the current limitations and potential avenues for future development. Importantly, we highlight a few examples of key areas of opportunity in immunology research where integrating functional metagenomic analyses of the microbiome can substantially enhance a mechanistic understanding of microbiome-immune interactions and their contributions to health and disease states.

Endosymbiont-derived metabolites are essential for tick host reproductive fitness.

Coxiella-like endosymbionts (CLE) are essential to the brown dog tick Rhipicephalus sanguineus for feeding and reproduction. This symbiosis is based on the supplementation of B vitamins lacking in the blood diet. The involvement of additional metabolites has been suggested, but no experimental evidence is available as yet to confirm a metabolic interaction. Here, we show that B vitamins and L-proline, both of which contribute to tick reproductive fitness, are produced by CLE. These findings demonstrate the importance of symbiont-derived metabolites for the host's persistence and shed light on the complex bacteria-host metabolic interaction, which can be channeled to manipulate and control tick populations.

Metabolomics reveals altered metabolites in cirrhotic patients with severe portal hypertension in Tibetan population.

Portal hypertension (PHT) presents a challenging issue of liver cirrhosis. This study aims to identify novel biomarkers for severe PHT (SPHT) and explore the pathophysiological mechanisms underlying PHT progression. Twenty-three Tibetan cirrhotic patients who underwent hepatic venous pressure gradient (HVPG) measurement were included. Eleven patients had an HVPG between 5 mmHg and 15 mmHg (MPHT), while 12 had an HVPG ≥16 mmHg (SPHT). Peripheral sera were analyzed using liquid chromatograph-mass spectrometer for metabolomic assessment. An additional 14 patients were recruited for validation of metabolites. Seven hundred forty-five metabolites were detected and significant differences in metabolomics between MPHT and SPHT patients were observed. Employing a threshold of p < 0.05 and a variable importance in projection score >1, 153 differential metabolites were identified. A significant number of these metabolites were lipids and lipid-like molecules. Pisumionoside and N-decanoylglycine (N-DG) exhibited the highest area under the curve (AUC) values (0.947 and 0.9091, respectively). Additional differential metabolites with AUC >0.8 included 6-(4-ethyl-2-methoxyphenoxy)-3,4,5-trihydroxyoxane-2-carboxylic acid, sphinganine 1-phosphate, 4-hydroxytriazolam, 4,5-dihydroorotic acid, 6-hydroxy-1H-indole-3-acetamide, 7alpha-(thiomethyl)spironolactone, 6-deoxohomodolichosterone, glutaminylisoleucine, taurocholic acid 3-sulfate, and Phe Ser. Enzyme-linked immunosorbent assay further confirmed elevated levels of sphinganine 1-phosphate, N-DG, and serotonin in SPHT patients. Significant disruptions in linoleic acid, amino acid, sphingolipid metabolisms, and the citrate cycle were observed in SPHT patients. Pisumionoside and N-DG are identified as promising biomarkers for SPHT. The progression of PHT may be associated with disturbances in lipid, linoleic acid, and amino acid metabolisms, as well as alterations in the citrate cycle.

Bio-guided isolation of a new sesquiterpene from Artemisia cina with anthelmintic activity against Haemonchus contortus L3 infective larvae.

Haemonchus contortus is a blood-feeding gastrointestinal parasite that impacts grazing sheep, causing economic losses in animal production. Due to its anthelmintic resistance, alternative antiparasitic treatments like plant-based anthelmintics are necessary to explore. Artemisia cina (Asteraceae) is a plant whose n-hexane extract and ethyl acetate extract exhibit anthelmintic activity against H. contortus, the n-hexane more active. To discover additional bioactive metabolites, a chemical analysis was performed on ethyl acetate extract, which presented an LC90 of 3.30 mg/mL and allowed the isolation of 11-[(1R,5S,7R,8R,10S,)-1,8-dihydroxy-5,10-dimethyl-4-oxodecahydroazulen-7-yl] acrylic acid. This new sesquiterpene was identified through one and two-dimensional NMR. The compound was named cinic acid and displayed an LC50 of 0.13 (0.11-0.14) mg/mL and LC90 of 0.40 (0.37-0.44) mg/mL, which, compared with ethyl acetate extract larvicidal activity, was 256-fold more active at LC50 and 15.71-fold at LC90. In this study, a new sesquiterpene with larvicidal activity against H. contortus L3 infective larvae was isolated from the ethyl acetate extract of Artemisia cina.

Converging cytokine and metabolite networks shape asymmetric T cell fate at the term human maternal-fetal interface.

Placentation presents immune conflict between mother and fetus, yet in normal pregnancy maternal immunity against infection is maintained without expense to fetal tolerance. This is believed to result from adaptations at the maternal-fetal interface (MFI) which affect T cell programming, but the identities (i.e., memory subsets and antigenic specificities) of T cells and the signals that mediate T cell fates and functions at the MFI remain poorly understood. We found intact recruitment programs as well as pro-inflammatory cytokine networks that can act on maternal T cells in an antigen-independent manner. These inflammatory signals elicit T cell expression of co-stimulatory receptors necessary for tissue retention, which can be engaged by local macrophages. Although pro-inflammatory molecules elicit T cell effector functions, we show that additional cytokine (TGF-β1) and metabolite (kynurenine) networks may converge to tune T cell function to those of sentinels. Together, we demonstrate an additional facet of fetal tolerance, wherein T cells are broadly recruited and restrained in an antigen-independent, cytokine/metabolite-dependent manner. These mechanisms provide insight into antigen-nonspecific T cell regulation, especially in tissue microenvironments where they are enriched.

Quantification of Efavirenz Hydroxymetabolites in Human Plasma Using LC-HRMS/MS.

Efavirenz (EFV) is a drug used to treat HIV. Low plasma concentrations of EFV result in suboptimal viral suppression, whereas high concentrations can cause adverse neuropsychiatric side reactions. Some studies have identified a correlation between the plasma concentrations of EFV metabolites and neurotoxicity. To our knowledge, no studies have investigated the metabolism of EFV in young children and its effect on treatment outcomes. Therefore, the aim of this study was to develop and validate a method for quantifying EFV and its metabolites in human plasma derived from children. Sample preparation was performed using protein precipitation of 100 µL plasma. Thereafter, an aliquot of the supernatant was used to quantify EFV, 7-hydroxyefavirenz (7-OH-EFV), 8-hydroxyefavirenz (8-OH-EFV), and a newly discovered metabolite ("EFAdeg") associated with 8-OH-EFV. A second aliquot of the supernatant was hydrolyzed using β-glucuronidase/arylsulfatase and used with the first aliquot to quantify phase II metabolites. The analyses were performed using a Dionex Ultimate 3000RS LC-system coupled with a Q Exactive Orbitrap mass spectrometer. The method has a measuring range of 100-50,000 ng/mL (EFV, 8-OH-EFV), 125-25,000 ng/mL (7-OH-EFV), and 200-10,000 ng/mL ("EFAdeg"). All criteria of the European Medicines Agency guidelines regarding precision, accuracy, and selectivity were met. Of note, carryover must be considered for 8-OH-EFV. Overall, the validated method was successfully applied to plasma samples obtained from children and confirmed the presence of the newly discovered metabolite, "EFAdeg." An LC-HRMS/MS method for the quantification of EFV and its phase I and II metabolites was developed and validated. This method is suitable for analyzing plasma samples from children. Furthermore, studies using this method identified an additional metabolite that may influence the concentration of 8-OH-EFV in patient samples.

Soil and unsaturated zone as a long-term source for pesticide metabolites in groundwater

Pesticide metabolites are frequently detected in groundwater, often exceeding the concentrations of their parent pesticides. Ceasing the application of certain pesticides has often not led to the expected decrease in metabolite concentrations in groundwater, which is potentially caused by residues in soil. Whereas pesticide residues in soils are well-documented, there are only few studies about metabolite residues. We investigated if the soil/unsaturated zone can act as a long-term source for metabolites in groundwater by combining soil analysis, groundwater analysis and numerical modelling. The field study focused on the herbicide chloridazon (CLZ) and its frequently detected metabolites desphenyl-chloridazon (DPC) and methyl-desphenyl-chloridazon (MDPC) while in the model additional pesticides and metabolites were considered. In soil samples from an agricultural area, where the last CLZ application was 5 to 10 years ago, we observed 10 times (DPC: 0.22 – 7.4 µg kg−1) and 6 times (MDPC: 0.12 – 3.1 µg kg−1) higher metabolite concentrations compared to CLZ (< 0.050 – 1.0 µg kg−1). Calculations suggested that the majority of the metabolites (DPC: 63 - 96%, MDPC: 74 – 97%) were sorbed despite their lower sorption tendency. The metabolite retention was in particular related to the organic carbon content. The calculated pore water concentrations were highest in the deepest part of the soil profile (75 – 100 cm) with median concentrations of 3.6 and 1.7 µg L−1 for DPC and MDPC, respectively. The groundwater concentrations of DPC and MDPC were 3 to 3.5 times higher in monitoring wells downgradient from the agricultural zone than upgradient of it. This increase highlights the potential of soil and unsaturated zone as a long-term metabolite source after the application stop of pesticides, consistent with the calculated elevated pore water concentrations. Numerical flow and transport model simulations suggested that this input from soil and unsaturated zone can cause elevated metabolite concentrations (> 0.1 µg L−1) in groundwater over more than one decade. The study highlights that soil and unsaturated zone can act as a long-term source of pesticide metabolites even if they have much higher mobility than the parent compound.

A pseudoautosomal glycosylation disorder prompts the revision of dolichol biosynthesis

Dolichol is a lipid critical for N-glycosylation as a carrier for activated sugars and nascent oligosaccharides. It is commonly thought to be directly produced from polyprenol by the enzyme SRD5A3. Instead, we found that dolichol synthesis requires a three-step detour involving additional metabolites, where SRD5A3 catalyzes only the second reaction. The first and third steps are performed by DHRSX, whose gene resides on the pseudoautosomal regions of the X and Y chromosomes. Accordingly, we report a pseudoautosomal-recessive disease presenting as a congenital disorder of glycosylation in patients with missense variants in DHRSX (DHRSX-CDG). Of note, DHRSX has a unique dual substrate and cofactor specificity, allowing it to act as a NAD+-dependent dehydrogenase and as a NADPH-dependent reductase in two non-consecutive steps. Thus, our work reveals unexpected complexity in the terminal steps of dolichol biosynthesis. Furthermore, we provide insights into the mechanism by which dolichol metabolism defects contribute to disease.

A Label-Free Approach for Relative Spatial Quantitation of c-di-GMP in Microbial Biofilms.

Microbial biofilms represent an important lifestyle for bacteria and are dynamic three-dimensional structures. Cyclic dimeric guanosine monophosphate (c-di-GMP) is a ubiquitous signaling molecule that is known to be tightly regulated with biofilm processes. While measurements of global levels of c-di-GMP have proven valuable toward understanding the genetic control of c-di-GMP production, there is a need for tools to observe the local changes of c-di-GMP production in biofilm processes. We have developed a label-free method for the direct detection of c-di-GMP in microbial colony biofilms using matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI). We applied this method to the enteric pathogen Vibrio cholerae, the marine symbiont V. fischeri, and the opportunistic pathogen Pseudomonas aeruginosa PA14 and detected spatial and temporal changes in c-di-GMP signal that accompanied genetic alterations in factors that synthesize and degrade the compound. We further demonstrated how this method can be simultaneously applied to detect additional metabolites of interest from a single sample.

Genomic and Transcriptome Analysis Reveals the Biosynthesis Network of Cordycepin in Cordyceps militaris.

Cordycepin is the primary active compound of Cordyceps militaris. However, the definitive genetic mechanism governing cordycepin synthesis in fruiting body growth and development remains elusive, necessitating further investigation. This study consists of 64 C. militaris strains collected from northeast China. The high-yielding cordycepin strain CMS19 was selected for the analysis of cordycepin production and the genetic basis of cordycepin anabolism. First, the whole-genome sequencing of CMS19 yielded a final size of 30.96 Mb with 8 contigs and 9781 protein-coding genes. The genome component revealed the presence of four additional secondary metabolite gene clusters compared with other published genomes, suggesting the potential for the production of new natural products. The analyses of evolutionary and genetic differentiation revealed a close relationship between C. militaris and Beauveria bassiana. The population of strains distributed in northeast China exhibited the significant genetic variation. Finally, functional genes associated with cordycepin synthesis were identified using a combination of genomic and transcriptomic analyses. A large number of functional genes associated with energy and purine metabolism were significantly enriched, facilitating the reconstruction of a hypothetical cordycepin metabolic pathway. Therefore, our speculation of the cordycepin metabolism pathway involved 24 genes initiating from the glycolysis and pentose phosphate pathways, progressing through purine metabolism, and culminating in the core region of cordycepin synthesis. These findings could offer fundamental support for scientific utilizations of C. militaris germplasm resources and standardized cultivation for cordycepin production.