High-resolution Mass Spectrometry Research Articles

Platelet storage failure—Metformin as causative agent

AbstractBackgroundPathogen reduction technology (PRT)‐treated apheresis platelets (APs) were returned without platelet swirl and with pH22°C < 6.2. The platelet donor was taking prescription levothyroxine and metformin plus over‐the‐counter medications and supplements. We hypothesized that either PRT or medication was causative.Study Design and MethodsOne AP from a double AP collection from this donor was PRT‐treated, the other unit untreated. Units were assessed over 7‐day storage with a standard panel of platelet assays and metabolomics using high resolution mass spectrometry. The dose effect of metformin on platelets over storage was evaluated in vitro using APs obtained from non‐medicated donors.ResultsThis donor's PRT‐ and non‐PRT treated paired units had pH values <6.2 by the end of day 2. Lactate generation rates in the PRT‐ and non‐PRT units were very high compared to previously reported values and approached that reported for anaerobic storage. Metabolomic analysis revealed impairments in a number of energy metabolic pathways between PRT‐ and non‐PRT platelets; however, this did not support a major causative role of PRT in the significant upregulation of lactic acid production. Metformin caused a dose‐dependent upregulation of glycolysis, resulting in pH decline.DiscussionWe conclude that metformin is the most likely cause for this donor's stored platelet pH failures. Metformin is commonly used to treat type 2 diabetes and is not a donor deferral medication. Further investigation is indicated into the potential impact of metformin on platelet storage characteristics, the potential implications for medication deferral, and the need for additional screening tools in the laboratory.

Enhanced industrial wastewater monitoring: method development for non-target screening of highly polar substances using ZIC-HILIC-HRMS.

Non-target screening (NTS) plays a major role in the monitoring and management of water bodies. While the NTS of moderate to non-polar substances is well-established, the screening of highly polar chemicals remains challenging. In this study, a robust separation method for highly polar substances using zwitterionic hydrophilic interaction liquid chromatography coupled with high-resolution mass spectrometry (ZIC-HILIC-HRMS) was developed. This method was specifically designed for the NTS of industrial wastewater, with the objective of capturing a wide range of polar contaminants in each acquisition run. Method validation included assessing key parameters such as repeatability, reproducibility, linearity, and limit of detection (LOD). For repeatability and reproducibility, the average %RSD of intensity and retention time across all substances in different matrices-solvent, influent, and effluent-remained below 6% and 1%, respectively (n = 10). The method demonstrated good linearity (R2 > 0.99) for 75% of the substances, while LODs varied between 0.1 and 40µg/L depending on the compound tested. The method was then applied for NTS analysis of untreated wastewater at various locations within a chemical industrial park. Additionally, the overall influent and effluent of an industrial wastewater treatment plant (WWTP) were monitored over a 10-day period. Principal component analysis (PCA) was performed to interpret the data, identifying irregularities in the wastewater content. Moreover, the method demonstrated the WWTP's ability to achieve an average removal efficiency of approximately 90% for this category of substances in this period, while also detecting their degradation products in the effluent. Finally, the method was successfully integrated into the daily monitoring routine of the WWTP, ensuring continuous surveillance and improved management of wastewater treatment processes.

Characterization of poly(A) and poly(T) tail lengths in plasmid DNA by liquid chromatography high-resolution mass spectrometry.

Rapid advances in messenger RNA (mRNA) technology necessitate effective analytical methods. This study describes the development of a novel in vitro method using ion-pair reversed-phase liquid chromatography coupled to high-resolution mass spectrometry (IP-RP-LC-HRMS) for assessing the poly(A) and complementary poly(T) tail lengths directly into the DNA template used to manufacture mRNA. Briefly, after the validation of poly(A) tail length in the plasmid by Sanger sequencing, double-stranded DNA fragments containing these tails in the plasmid of interest were amplified by thepolymerase chain reaction (PCR), purified on silica column, and digested with restriction enzymes ClaI and HindIII. Gel or capillary electrophoresis confirmed sample quality and enzymatic digestion efficiency. Subsequently, poly(A) and complementary poly(T) tails were extracted and analyzed by LC-MS to determine their length and heterogeneity at a single-nucleotide resolution. Three DNA templates containing poly(A) tail lengths of 60A-G, 95A, or 108A were studied. LC-MS results correlated well with Sanger sequencing, identifying major populations of 60A-G, 95A, or 108A. Surprisingly, unlike Sanger sequencing, LC-MS analysis revealed minor poly(A) populations with lengths longer or shorter than the theoretically encoded poly(A) tail length. This finding could be explained by (i) the slippage of bacterial DNA polymerase I during plasmid replication in bacterial culture, which occurs on repeat mononucleotide sequences, or (ii) the slippage of Q5® High-Fidelity DNA Polymerase during PCR amplification. In conclusion, the method is easy, rapid, and accurate and could replace Sanger sequencing to assess the poly(A) and complementary poly(T) tail lengths in plasmid DNA.

Pregnancy influences on the rumen environment of Angus heifers differing in feed efficiency

With an expected increase in population by 2050, the demand for high-quality protein for human consumption will increase. To improve the sustainability of US cattle production, producers and researchers have historically focused on improving the feed efficiency of steers through improvements in genetics, nutrition, and microbiome management, producing a more marketable beef product. However, without a successful pregnancy, there would be no marketable animal to feed. The objective of this study was to examine the impact of pregnancy on the rumen environment, microbial communities, and the correlation to feed efficiency status in Angus heifers. Utilizing 17 cannulated Angus heifers, feed efficiency status was determined using the GrowSafe 8000 feed intake monitoring system to monitor feed intake for a 70d trial period to calculate residual feed intake. Following the trial, heifers were bred and 40mL rumen fluid and content samples were collected every two weeks during gestation. Metagenomic DNA was extracted from the rumen samples, sequencing libraries were prepared targeting the bacterial V4 region of the 16S rRNA gene, and resultant libraries were sequenced on an Illumina MiSeq. All microbial analyses were conducted in the R environment v2.6.2 where alpha diversity, beta diversity, and differential abundances were determined. Metabolites were identified using ultra high-performance liquid chromatography high resolution mass spectrometry, and Metabolomic Analysis and Visualization Engine was used to select metabolite peaks. Differential abundance analyses using “ANCOMBC” indicated 10 amplicon sequence variants (ASVs), assigned to seven Prevotella and three Succiniclasticum, significantly varied among weeks of gestation (P<0.05). Based on a one-way ANOVA, 90 metabolites were determined significant throughout pregnancy (P<0.05). The 10 metabolites with the highest variable importance of projection scores from a partial least squares discriminant analysis were used to calculate correlations between. Of the 10 ASVs and 10 metabolites, significant correlations with feed efficiency status were found at various time points (P<0.05). The rumen microbiome and its fermentative profile were different at various time points during pregnancy with several correlations to feed efficiency status. Identifying pregnancy-related microbial and metabolite changes may aid producers to anticipate nutritional or management adjustments, ultimately contributing to the sustainability of beef production.

Integration of high-resolution mass spectrometry technology with molecular network analysis and systems biology techniques to elucidate the active ingredients and mechanisms of Shiduqing capsules.

Shiduqing Capsules, a well-known Chinese patent medicine, are widely used clinically for the treatment of pruritus. However, to date, there is a lack of research on its pharmacological substances and mechanisms of action. In the current study, the chemical components of Shiduqing Capsules were identified using UHPLC-QE-Orbitrap-MS technology. Molecular network analysis was employed to identify structurally similar compounds to the known chemical components. The potential molecular targets of the active ingredients were predicted using the SwissTargetPrediction website. The identified targets were further analyzed using gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis through the DAVID database. Molecular docking was used to validate the network pharmacology results. Ultimately, A total of 51 chemical components of Shiduqing Capsules were identified. Molecular network analysis identified 21 flavonoids and 13 terpenoids. The core targets of these ingredients include TP53, AKT1, and STAT3. GO and KEGG enrichment analysis revealed 1,371 different biological functions and 177 signaling pathways. Molecular docking confirmed the high affinity between multiple core active ingredients of Shiduqing Capsules and pruritus targets. In conclusion, the effective ingredients of Shiduqing Capsules exert a multifaceted therapeutic effect on pruritus through multiple targets and pathways.

Enhanced removal of trace-level per- and polyfluoroalkyl substances (PFAS) from drinking water using granular activated carbon (GAC): the role of ozonation.

Granular activated carbon (GAC) is a promising approach for removing per- and polyfluoroalkyl substances (PFAS) from drinking water. However, GAC filters usually suffer early PFAS breakthroughs due to the competition between PFAS and natural organic matter (NOM) during sorption. The present study investigated the possibility of using ozonation to enhance the GAC performance for PFAS removal. Rapid-small-scale-column tests were performed for three GACs using filtered or filtered and ozonated water. NOM was fractionated using liquid chromatography-organic carbon detection (LC-OCD), and 76 ambient PFAS were quantified using ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-HRMS). Although ozonation did not remove either NOM or PFAS, it altered their composition in water. Ozonation reduced the hydrophobicity and the molecular size of natural organic matter (NOM). On the other hand, ozonation oxidized some PFAS precursors, leading to a higher total detected PFAS concentration in the filtered and ozonated water than in filtered water (10.2 ± 0.7 ng/L vs. 9.5 ± 0.7 ng/L). The impact of ozonation on GAC performance for NOM and PFAS removal mainly depended on GAC properties. GAC with a lower micropore volume showed an improvement in NOM and PFAS removal when ozonation was applied, approaching the performance of GACs with higher micropore volumes.

Synthesis and Antifungal Activity Evaluation of Novel L-Carvone-Based 1,3,4-Thiadiazole-amide Derivatives as a Potential Succinate Dehydrogenase Inhibitor.

In an effort to explore new-type high-efficiency antifungal agents, 25 novel L-carvone-based 1,3,4-thiadiazole-amide derivatives were designed, synthesized, and structurally characterized by IR, 1H NMR, 13C NMR, and high-resolution mass spectrometry (HRMS) analyses. The antifungal activity of the target compounds was preliminarily assayed at a concentration of 50 μg/mL, and boscalid, a commercialized fungicide identified as a succinate dehydrogenase inhibitor (SDHI), was employed as the positive control. It was found that all of the target compounds showed moderate to potent antifungal activity against the tested fungi compared to boscalid. Surprisingly, compound 4b exhibited broad-spectrum and significant inhibition activity against the growth of eight phytopathogenic strains with inhibitory rates of 67-89%. Further, the results of the EC50 value test suggested that the EC50 values of compound 4b against Physalospora piricola and Colletotrichum orbiculare were 16.33 and 18.06 μg/mL, respectively, and both of them were better than those of boscalid (16.64 and >50). Therefore, compound 4b deserves further study as a lead compound for novel fungicides. In addition, the inhibitory activity of compound 4b against succinate dehydrogenase (SDH) was evaluated as well to prove that compound 4b (IC50 = 3.38 μM) displayed higher SDH-inhibition activity than boscalid (IC50 = 7.02 μM). The binding mode of compound 4b and SDH was simulated by molecular docking and found to be similar to that of boscalid. The structure-activity relationships (SARs) of the target compounds were analyzed by establishing a 3D-QSAR model. Besides, a 4b-loaded complex 4b/CSTA on a reported L-carvone-based nanochitosan carrier CSTA containing the 1,3,4-thiadiazole-amide group was constructed, and its sustained release performance was investigated in the EtOH-H2O system (1:9, v/v). The complex 4b/CSTA exhibited preferred sustained release performance, indicating its potential for developing environmentally friendly nanofungicides.

Advantages of Metabolomics-Based Multivariate Machine Learning to Predict Disease Severity: Example of COVID

The COVID-19 outbreak caused saturations of hospitals, highlighting the importance of early patient triage to optimize resource prioritization. Herein, our objective was to test if high definition metabolomics, combined with ML, can improve prognostication and triage performance over standard clinical parameters using COVID infection as an example. Using high resolution mass spectrometry, we obtained metabolomics profiles of patients and combined them with clinical parameters to design machine learning (ML) algorithms predicting severity (herein determined as the need for mechanical ventilation during patient care). A total of 64 PCR-positive COVID patients at the Poitiers CHU were recruited. Clinical and metabolomics investigations were conducted 8 days after the onset of symptoms. We show that standard clinical parameters could predict severity with good performance (AUC of the ROC curve: 0.85), using SpO2, first respiratory rate, Horowitz quotient and age as the most important variables. However, the performance of the prediction was substantially improved by the use of metabolomics (AUC = 0.92). Our small-scale study demonstrates that metabolomics can improve the performance of diagnosis and prognosis algorithms, and thus be a key player in the future discovery of new biological signals. This technique is easily deployable in the clinic, and combined with machine learning, it can help design the mathematical models needed to advance towards personalized medicine.

Investigation of the mechanism of [M-H]+ ion formation in photoionized N-alkyl-substituted thieno[3,4-c]-pyrrole-4,6-dione derivatives during higher order MSn high-resolution mass spectrometry.

The mechanism underlying dopant-assisted atmospheric pressure photoionization's (APPI) formation of ions is unclear and still under debate for many chemical classes. In this study, we reexamined the gas-phase reaction mechanisms responsible for the generation of [M-H]+ precursor ions, resulting from the loss of a single hydrogen atom, in a series of N-alkyl-substituted thieno[3,4-c]-pyrrole-4,6-dione (TPD) derivatives. Atmospheric pressure photoionization combined with higher order MS/MSn using high-resolution mass spectrometry (APPI-HR-CID-MSn) and electronic structure calculations using density functional theory were used to determine the chemical structure of observed [M-H]+ ions. As a result, the higher order MSn (n = 3) experiments revealed a reversed Diels-Alder fragmentation mechanism, leading to a common fragment ion at m/z 322 from the studied [M1-5-H]+ ion species. In addition, the calculation for two chemical structure models (N-alkyl-TPD1 and N-alkyl-TPD5) showed that the fragment structure, resulting from the removal of the hydrogen atom connected to the third carbon atom of the N-alkyl side chain, has a more stable cyclic form compared with the linear one. The proposed chemical structure of the N-alkyl TPD ion species, following the loss of a single hydrogen atom, was revealed during APPI-HR-CID-MSn (n= 3) experiments on the [M-H]+ species. Hydrogen radical (H•) abstraction from the alkyl side chain (e.g., hexyl, heptyl, octyl, 2-ethylhexyl, and nonyl) triggered a rearrangement in the radical cation structure of the N-alkyl-TPD derivatives, initiating cyclization and forming a six-membered ring that connects the oxygen atom to the third carbon atom in the alkyl chain. In addition, theoretical calculations supported the APPI-HR-CID-MSn (n = 3) experiments by demonstrating that the proposed chemical structure, resulting from the intramolecular cyclization of the N-alkyl-TPD ion species, was stable in the presence of chlorobenzene. These findings will aid the structural determination and elucidation of molecules with similar core structures.

Skeletal Editing of Energetic Materials: Acid-Catalyzed One-Step Synthesis of Bridged Triazoles as High-Energy-Density Materials via the Nef Reaction.

Thermally stable insensitive energetic materials have captivated significant attention from the global research community due to their potential impact. In this study, a series of symmetric and asymmetric nitromethyl-bridged triazole compounds were synthesized from pyrimidine moieties via a skeletal editing approach. Additionally, carbonyl-bridged compounds were synthesized in a single step by using acid-catalyzed Nef reactions from their nitromethyl precursors. Peripheral modifications of pyrimidine resulted in fused energetic moieties. All synthesized compounds were fully characterized by using infrared spectroscopy, high-resolution mass spectrometry, multinuclear magnetic resonance spectroscopy, elemental analysis, and differential scanning calorimetry. Single-crystal X-ray diffraction analysis confirmed the structures of compounds 4 and 10. The newly synthesized moieties exhibit densities ranging from 1.75 to 1.86 g cm-3, detonation velocities between 8044 and 8608 m s-1, and detonation pressures between 23.10 and 30.31 GPa. Notably, compounds 9 and 10 demonstrate exceptional heat resistance, with decomposition temperatures of 315 and 335 °C, respectively. Computational studies, including density functional theory, quantum theory of atoms in molecules, noncovalent interactions, and electrostatic surface potential analysis, account for hydrogen-bonding and noncovalent interactions. This work highlights the potential of skeletal editing in the development of high-performing, thermally stable energetic materials.

Chemical characterization of wheat-based waste derived from a pharmaceutical process for its potential valorization

IntroductionWe report the analysis and characterization and the preliminary biological evaluation, of both liquid and solid wastes obtained from the processing of wheat (Triticum vulgare) to produce the most iconic phytostimulin-based pharmaceutical products. The study aims to verify whether the waste can be reused in another process and not destined to its simple destructive disposal.MethodsIn this perspective, we first carried out an in-depth chemical-physical analysis of the waste together with a biocompatibility evaluation to plan the feasible final choice of waste destination. The liquid and solid waste derived from the processing of wheat extract were analyzed and characterized through ultra-high-performance liquid chromatography coupled with high-resolution Orbitrap mass spectrometry (UHPLC-Q-Orbitrap HRMS).ResultsResults highlight that ferulic acid represent the most abundant phenolic compound for solid waste with a content of 89.782 mg/kg and dihydroferulic acid is the predominant for liquid waste (6.24 mg/L). These concentrations represent 55.87% and 84.39% of the total concentration of bioactive compounds for liquid and solid waste, respectively. The antioxidant activity registered for the solid extract was 8.598 and 7.262 mmol trolox/kg, respectively for ABTS and FRAP assays. The total phenolic content (TPC) in the liquid extract undergoes a significant percentage reduction compared to the solid waste. As regards toxicity, both liquid and solid wastes were investigated in vitro preclinical models of human skin (HaCaT cells and HDFa) after 24, 48, and 72 h of exposure. No cytotoxic effect was noted even at the highest tested concentration (100 μg/mL) at 72 h.DiscussionOverall, considering its chemo-physical features and active ingredients, we believe that this waste is highly reusable as a starting material for the development of cosmeceutical products. Thus, this study allows us to motivate the destination of the waste of the production in a recyclable raw material for additional industrial processes, thereby promoting an eco-friendly circular economy operation.

Deciphering Isotopic Fine Structures of Silylated Compounds in Gas Chromatography-Vacuum Photoionization Orbitrap Mass Spectrometry of Bio-Oils.

We introduce vacuum resonance-enhanced multiphoton ionization (REMPI) with high-resolution Orbitrap Fourier transform mass spectrometry (FTMS) for analyzing silylated polar compounds. UV laser radiation at 248 nm sensitively and selectively targets aromatic constituents, while high-resolution mass spectrometry (HRMS) enables high-performance mass spectrometric detection. This workflow enhances the detection confidence of polar constituents by identifying unique isotopologue patterns, including at the isotopic fine structure (IFS) level, in analytical standards and complex bio-oils. A direct and derivatized gas chromatography (GC) procedure on a polar standard component mixture allowed us to explore the general ionization and detection characteristics of REMPI FTMS. HRMS enabled the examination of the complex isotopologue profiles, revealing distinct patterns for the CHOxSiy-class compounds. Particularly in complex mixtures, this isobaric/isonucleonic complexity exceeded the classical mass resolution capabilities of the employed Orbitrap D30 series and prompted the usage of prolonged transients via an external data acquisition system. This procedure substantially improved mass spectrometric results by recording the unreduced time-domain transient data for up to 2 s. Notably, the ability to distinguish diagnostic isotopic pairs, such as 12C/29Si vs 13C/28Si with a mass split of ∼3.79 mDa and 13C12C/28Si29Si vs 13C2/28Si2, with an approximate mass difference of ∼3.32 mDa, demonstrates a significant and expected performance improvement. Finally, we benchmark the GC HRMS methodology to identify silylated oxygenated and nitrogen-containing constituents in ultracomplex bio-oil samples. The presented approach of utilizing the silicon isotope pattern and unique isotopologue mass splits for increasing attribution confidence can be applied beyond bio-oils toward the general GC analyses of polar oxygenates.

Chromatographic analysis of ponatinib and its impurities: method development, validation, and identification of new degradation product

BackgroundPonatinib, a third-generation tyrosine kinase inhibitor, is employed in the management of adult chronic myeloid leukemia. Nevertheless, the presence of process impurities and degradation impurities linked to ponatinib may potentially influence its effectiveness and safety. Therefore, the objective of this research was to establish a robust liquid chromatography method and systematically validate it for the detection of substances related to ponatinib.MethodsThe separation of ponatinib and its impurities was conducted using an Agilent 5HC-C18 chromatographic column (4.6 mm × 250 mm, 5 μm). The mobile phase A comprised a mixture of water and acetonitrile in a 9:1 ratio, with an aqueous solution of pH 2.4 containing 2 mM potassium dihydrogen phosphate and 0.4% triethylamine. Mobile phase B, consisting of acetonitrile, was eluted in a gradient fashion. The flow rate was set at 1.0 mL/min, detection wavelength at 250 nm, column temperature at 40°C, and injection volume at 10 μL.ResultsThe method demonstrated high specificity, sensitivity, solution stability, linearity, precision, accuracy, and robustness. Additionally, this research unveiled a novel compound, imp-B, generated via the oxidative degradation of ponatinib. The molecular structure of the newly discovered product was elucidated through the utilization of nuclear magnetic resonance (NMR) and high-resolution mass spectrometry (HRMS).ConclusionIn conclusion, the chromatographic method developed in this study has the potential to be utilized for the detection of ponatinib and its impurities, thereby offering significant insights for quality assessment in ponatinib research.

UPLC-QToF-MS/MS screening and characterization of Symphorema polyandrum Wight and in vitro assessment of its antioxidant, anticancer, and anti-inflammatory potential.

Symphorema polyandrum belongs to the Lamiaceae family and is locally known as Badichang or mahasindhu. In this study, we performed Soxhlet extraction to prepare methanolic and hydromethanolic extracts, followed by quantification of their total phenolic content and total flavonoid content. Qualitative analysis of both the extracts was conducted to determine the presence of different phytochemicals. In addition, we aimed to identify the important phytochemical constituents in the methanolic extracts of S. polyandrum (SPM) using ultra-performance liquid chromatography hyphenated with high-resolution mass spectrometry (UPLC-ESI-QTOF-MSE). Furthermore, this study investigated the antioxidant, anticancer and anti-inflammatory properties of SPM and its safety profile in the normal fibroblastcell line L929. A colony proliferation assay and a Griess assay were performed to evaluate the effects of SPM on colony formation and nitric oxide (NO) production. A total of 13 important phytochemicals were identified and reported. The methanolic extract of SPM demonstrated significant antioxidant activity. SPM also showed substantial antiproliferative activity on MDA-MB-231 triple-negative breast cancer cells, with an IC50 value of 45.53± 1.63µg/ml, and also reduced the survival of these cancer cells by promoting nuclear fragmentation and condensation without causing harm to normal cells. SPM inhibits the colony formation and reduces the nitric oxide (NO) production. The anti-inflammatory potential of SPM was assessed utilizing the murine alveolar macrophages (J774.A.1) as an in vitro model, and SPM effectively lowered the levels of proinflammatory cytokines such as TNF-α and IL-6. These findings emphasized the antiproliferative potential of SPM to cancer cells, along with its anti-inflammatory, and antioxidant capabilities, indicating the therapeutic efficacy of this medicinal plant.

Measuring 15N and 13C Enrichment Levels in Sparsely Labeled Proteins Using High-Resolution and Tandem Mass Spectrometry.

Isotope labeling of both 15N and 13C in selected amino acids in a protein, known as sparse labeling, is an alternative to uniform labeling and is particularly useful for proteins that must be expressed using mammalian cells, including glycoproteins. High levels of enrichment in the selected amino acids enable multidimensional heteronuclear NMR measurements of glycoprotein three-dimensional structure. Mass spectrometry provides a means to quantify the degree of enrichment. Mass spectrometric measurements of tryptic peptides of a selectively labeled glycoprotein expressed in HEK293 cells revealed complicated isotope patterns which consisted of many overlapping isotope patterns from intermediately labeled peptides, which complicates the determination of the label incorporation. Two challenges are uncovered by these measurements. Metabolic scrambling of amino groups can reduce the 15N content of enriched amino acids or increase the 15N in nontarget amino acids. Also, undefined, unlabeled medium components may dilute the enrichment level of labeled amino acids. The impact of this unexpected metabolic scrambling was overcome by simulating isotope patterns for all isotope-labeled peptide states and generating linear combinations to fit to the data. This method has been used to determine the percent incorporation of 15N and 13C labels and has identified several metabolic scrambling effects that were previously undetected in NMR experiments. Ultrahigh mass resolution is also utilized to obtain isotopic fine structure, from which enrichment levels of 15N and 13C can be assigned unequivocally. Finally, tandem mass spectrometry can be used to confirm the location of heavy isotope labels in the peptides.

Molecular characteristics of dissolved organic matter in the porewater of "Challenger" Deep sediments, Mariana Trench

Hadal trenches (> 6,000 m water depth) have been revealed as hotspots of organic carbon deposition and mineralization. Here, we present the molecular compositions of porewater dissolved organic matter (DOM) at the “Challenger” Deep (Site MT02; 10,954 m water depth) sediments of the Mariana Trench and the adjacent abyssal plain sediments (Site MT04; 5,800 m water depth) using ultra high-resolution Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS). The "Challenger" Deep sediments are characterized by higher abundance of recalcitrant compounds, mainly composed of highly unsaturated compounds (79.7%) and carboxyl-rich alicyclic molecules (57.1%), compared to the abyssal plain sediments (68.3%&51.5%). Principal component analysis suggests that TOC content in the sediments exerts an important control on the molecular characteristics of porewater DOM. It is likely that higher TOC content triggers elevated microbial-mediated organic matter mineralization, thereby forming more refractory organic matter compounds. These results improved the knowledge of the poorly-understood DOM compositions and microbial organic matter degradation in the ultra-deep, extreme ocean environment.

Insights into the Chemical Exposome during Pregnancy: A Non-Targeted Analysis of Preterm and Term Births.

Human-made chemicals are ubiquitous, leading to chronic exposure to complex mixtures of potentially harmful substances. We investigated chemical exposures in pregnant women in New York City by applying a non-targeted analysis (NTA) workflow to 95 paired prenatal urine and serum samples (35 pairs of preterm birth) collected as part of the New York University Children's Health and Environment Study. We analyzed all samples using liquid chromatography coupled with Orbitrap high-resolution mass spectrometry in both positive and negative electrospray ionization modes, employing full scan and data-dependent MS/MS fragmentation scans. We detected a total of 1524 chemical features for annotation, with 12 chemicals confirmed by authentic standards. Two confirmed chemicals dodecyltrimethylammonium and N,N-dimethyldecylamine N-oxide appear to not have been previously reported in human blood samples. We observed a statistically significant differential enrichment between urine and serum samples, as well as between preterm and term birth (p < 0.0001) in serum samples. When comparing between preterm and term births, an exogenous contaminant, 1,4-cyclohexanedicarboxylic acid (tentative), showed a statistical significance difference (p = 0.003) with more abundance in preterm birth in serum. An example of chemical associations (12 associations in total) observed was between surfactants (tertiary amines) and endogenous metabolites (fatty acid amides).

The biosynthesis and impacts of cytokinins on growth of the oyster mushroom, Pleurotus ostreatus

ABSTRACT While a lot is known about cytokinins (CKs) and their actions at the molecular and cellular levels in plants, much less is known about the function of CKs in other kingdoms such as fungi. CKs have been detected in a wide range of fungal species where they play roles ranging from enhancing the virulence of phytopathogens to fortifying plant growth when secreted from fungal symbionts. However, the role of CKs where they concern fungal physiology, apart from plant associations, remains largely uncharacterized. Profiling by UHPLC-HRMS/MS (ultrahigh-performance liquid chromatography–high-resolution tandem mass spectrometry) revealed that Pleurotus ostreatus (oyster mushroom) produces CKs in vitro in both liquid and solid cultures. During fungal growth, CK profiling patterns were consistent with previous suggestions that tRNA degradation products might play a role in the physiological development of fungi. It confirms that those products are CKs that act as fungal growth regulators. Moreover, P. ostreatus was shown to respond to exogenous applications of aromatic and isoprenoid CKs, and their effects were dependent on the dose and CK type in a biphasic manner consistent with hormone action. N 6-benzyladenine (BAP), kinetin (KIN), N 6-isopentenyladenine (iP), and trans-zeatin (tZ) bioassays all revealed hormesis-type responses. Accordingly, at low doses, mycelium colony diameter, biomass accumulation, and changes in morphology were stimulated, whereas at high doses only inhibitory effects were observed. Thus, CKs may act as “mycohormones” and consequently have potential for applications in fungal agriculture and medicinal compound production.

Design, Synthesis, and Evaluation of EA-Sulfonamides and Indazole-Sulfonamides as Promising Anticancer Agents: Molecular Docking, ADME Prediction, and Molecular Dynamics Simulations

New EA-sulfonamides and indazole-sulfonamides were synthesized, characterized, and evaluated for their anticancer activities. The target compound structures were elucidated using various spectroscopic techniques such as NMR-{1H and 13C}, infrared spectroscopy, and high-resolution mass spectrometry. The anticancer activities of the novel compounds were evaluated against four human cancer cell lines, namely A-549, MCF-7, Hs-683, and SK-MEL-28 as well as the normal cell line HaCaT, using 5-fluorouracil and etoposide as reference drugs. Among the tested compounds, 9, 10, and 13 exhibited potent anticancer activities which are better than or similar to the reference compounds 5-fluorouracil and etoposide, against the A-549, MCF-7, and Hs-683 cancer cell lines, with IC50 values ranging from 0.1 to 1 μM. Molecular docking studies of compounds 9, 10, and 13 showed a strong binding with selected protein kinase targets, which are linked to the tested cancer types. Furthermore, the analysis of the molecular dynamics simulation results demonstrated that compound 9 exhibits significant stability when bound to both JAK3 and ROCK1 kinases. This new compound has the potential to be developed as a novel therapeutic agent against various cancers.

Decreasing the Uncertainty in the Comparison of Molecular Fingerprints of Organic Aerosols with H/D Exchange Mass Spectrometry.

High-resolution mass spectrometry (HRMS) has become an indispensable tool in the characterization of organic aerosols (OA) providing information on air quality, health assessment, climate trends, reactions, and source apportionment. Spectra-derived lists of formulas and their relative abundances are used to compare ambient OA from different sources or to monitor secondary OA formation under controlled laboratory conditions in smog chamber experiments. Various techniques are implemented to visualize common and unique features, series of precursors, and products. The disadvantage of this conventional approach is in associating elemental compositions to specific compounds, while due to several analytical limitations, the structural information remains hidden. We argue that some of the conclusions derived from this data analysis can be misleading. In this study, we applied in-ESI source H/D exchange (HDX), which facilitated enumeration of labile protons in molecules behind elemental compositions of OA. We applied this technique to compare OA from three different locations representing urban, forest, and marine environments and to examine tentative chemical information derived from Kendrick mass defect (KMD) series analysis. Significant discrepancies were found between numbers of labile protons in protogenic functional groups and the stoichiometry of chemical reactions, which are associated with KMD series. Only a portion of chemical pairs matched target stoichiometries, which highlights the existing limitations in environmental applications of conventional formula-based HRMS data interpretation strategies.