High-resolution Mass Spectrometry Research Articles

Reported recreational drug and new psychoactive substance use versus laboratory detection of substances by high-resolution mass spectrometry in patients presenting to an emergency department in London with acute drug toxicity

Introduction Clinicians managing patients with acute recreational drug or new psychoactive substance toxicity typically depend on self-reported drug(s) used. This study compares patient self-report (and/or from other sources) to the substance(s) that were subsequently identified in serum. Methods A prospective sample of 1,000 adults presenting to a tertiary care, urban emergency department in London, United Kingdom, with acute recreational drug/new psychoactive substance toxicity was collected from 1 February 2019 to 2 February 2020. A total of 939 appropriate samples underwent qualitative analysis by high-resolution mass spectrometry with comparison to a database of drugs/metabolites. Data on the stated drug(s) used were extracted from the routine medical chart/records; results were batched by drug class, when appropriate, and analysis was performed using R software. Results Seven hundred and ninety-nine (85.1%) patients were male with a median (IQR) age of 34 years (27 to 42 years). Six hundred and thirty-five (67.6%) patients reported using two or more drugs. The median (IQR) positive predictive value of a self-report substance having been taken was 0.68 (IQR: 0.44–0.86); conversely, the median negative predictive value of a substance having not been taken was 0.90 (IQR: 0.53–0.95). There was variability in the accuracy of reporting. For example, self-reported opioid use had a 90.5% likelihood that opioids were detected on analysis, whereas hallucinogens were only detected in 18.8% of samples when use was reported. Individuals were also mostly accurate in not underreporting substances. For example, those not explicitly reporting gamma-hydroxybutyrate use were 97.5% truly negative. Discussion Overall, most users were relatively accurate in their self-report of what class of drugs they had used, although there was variability in this accuracy. However, other drugs were present even when not reported, for example, opioids with disproportionate detection of prescription and over-the-counter (non-prescription) opioids that were unreported. Conclusions Self-report (and/or collateral reports) had overall relatively high concordance with the likelihood that a substance was, or was not, recently used. Therefore, clinicians can make initial treatment decisions based on the self-reported drug(s) used in most cases.

Revisiting the nature and pharmacodynamics of tacrolimus metabolites.

The toxicity of tacrolimus metabolites and their potential pharmacodynamic (PD) interactions with tacrolimus might respectively explain the surprising combination of higher toxicity and lower efficacy of tacrolimus despite normal blood concentrations, described in extensive metabolizers.To evaluate such interactions, we produced tacrolimus metabolites in vitro and characterized them by high resolution mass spectrometry (HRMS, for all) and nuclear magnetic resonance (NMR, for the most abundant, M-I). We quantified tacrolimus metabolites and checked their structure in patient whole blood and peripheral blood mononuclear cells (PBMC). We explored the interactions of M-I with tacrolimus in silico, in vitro and ex vivo.In vitro metabolization produced isoforms of tacrolimus and of its metabolites M-I and M-III, whose HRMS fragmentation suggested an open-ring structure. M-I and M-III open-ring isomers were also observed in patient blood. By contrast, NMR could not detect these open-ring forms. Transplant patients expressing CYP3A5 exhibited higher M-I/TAC ratios in blood and PBMC than non-expressers.Molecular Dynamics simulations showed that: all possible tacrolimus metabolites and isomers bind FKPB12; and the hypothetical open-ring structures induce looser binding between FKBP12 and calcineurins, leading to lower CN inhibition. In vitro, tacrolimus bound FKPB12 with more affinity than purified M-I, and the pool of tacrolimus metabolites and purified M-I had only weak inhibitory activity on IL2 secretion and not at all on NFAT nuclear translocation. M-I showed no competitive effect with tacrolimus on either test. Finally, M-I or the metabolite pool did not significantly interact with tacrolimus MLR suppression, thus eliminating a pharmacodynamic interaction.

Synthesis, crystal structures and antiproliferative activities of a new indole-containing dipyridylmethanone hydrazone Schiff base and its cadmium(II) complex.

In this study, we introduce a novel indole-containing pyridine-based Schiff base, (E)-2-({[bis(pyridin-2-yl)methylidene]hydrazin-1-ylidene}methyl)-1H-indole, C20H15N5 (2-DPHI), and its cadmium(II) complex poly[[2-({[bis(pyridin-2-yl)methylidene]hydrazin-1-ylidene}methyl)-1H-indole]di-μ-chlorido-cadmium(II)], [CdCl2(C20H15N5)]n (pCd2), as potential anticancer agents. The Schiff base was synthesized by reacting dipyridylmethanone hydrazone with indole-2-formaldehyde, while the cadmium complex was prepared by combining CdCl2 and 2-DPHI in methanol at room temperature. Both compounds were evaluated for their cytotoxicity against three human cancer cell lines (A375, A549 and HeLa) and a normal cell line (HFF-1). The ligand 2-DPHI exhibited notable antitumour activity, with an IC50 value of 12.22 µM against A375 and 15.17 µM against A549 after 48 h, while the pCd2 complex showed an even stronger inhibition of A375 cells, with an IC50 value of 4.88 µM, outperforming both 2-DPHI and CdCl2. Both compounds demonstrated lower toxicity towards normal cells compared to cancer cells. The structures of 2-DPHI and pCd2 were fully characterized using single-crystal X-ray diffraction, elemental analysis, high-resolution mass spectrometry and FT-IR, 1H NMR, 13C NMR and UV-Vis spectroscopy.

7Method for Detection of Naturally Occurring Toxins in Human Urine Using Liquid Chromatography High Resolution Mass Spectrometry.

Natural toxins present an ongoing risk for human exposure that requires a rapid, accurate diagnosis for proper response. In this study, a qualitative liquid chromatography high resolution mass spectrometry (LC-HRMS) method was developed and validated for the detection of a large, diverse selection of natural toxins. Data-dependent acquisition was performed to identify compounds with an in-house mass spectral library of 129 hazardous toxins that originate from plants, animals, and fungi. All 129 compounds were spiked into human urine, extracted, and evaluated for spectral library matching. Of these, 92 toxins met the quality criteria and underwent validation in urine matrix based on American National Standards Institute (ANSI) guidelines. A generalized workflow for method expansion was developed and enables the rapid addition of relevant compounds to the established method. This LC-HRMS method achieves efficient detection of natural toxins in urine, and the created workflow can rapidly increase compound coverage via method expansion.

Influence of Engine Oil Degradation on Sliding Bearings, with Special Focus on Different Degrees of Nitration

Bismuth (Bi) can be considered for use as a green substitute for lead in bearing applications. However, accelerated Bi oxidation can occur during operation, creating a brittle surface and resulting in premature seizure failure. Thus, the aim of this study was to evaluate the influence of engine oil degradation, especially nitration processes, on the oxidation of Bi. Tailor-made artificially aged oils with different degrees of nitration were produced and utilized in static bearing oxidation tests. By means of X-ray photoelectron spectroscopy (XPS), the Bi surfaces were analyzed regarding their chemical compositions after the tests. The results were correlated with the respective oil conditions determined via conventional parameters as well as high-resolution mass spectrometry. The findings obtained revealed a direct correlation between the amount of Bi-oxide and the nitration values of the oil, proving there was a positive impact of nitration products on the oxidation of the Bi surfaces. A comparison with the Bi content in the oils demonstrated a protective effect of the oxide layer as the Bi content declined with an increase in nitration. Overall, valuable insight into understanding the impact of oil condition on engine parts is given, and the importance of testing engine parts with aged lubricants is emphasized.

Formic acid dehydrogenation using Ruthenium-POP pincer complexes in ionic liquids

Formic acid is one of the most promising candidates for the long-term storage of hydrogen in liquid form. Herein, we present a new collection of ruthenium pincer complexes of the general formula [RuHCl(POP)(PPh3)] using commercially available or easy-to-synthesize tridentate xantphos-type POP pincer ligands. We applied these complexes in the dehydrogenation of formic acid to CO2 and H2 using the ionic liquid BMIM OAc (1-butyl-3-methylimidazolium acetate) as solvent under mild, reflux-free conditions. The best performing catalyst with respect to maximum turnover frequency, the literature-known complex [RuHCl(xantphos)(PPh3)] Ru-1, produced a maximum turnover frequency of 4525 h−1 with 74% conversion after 10 min at 90 °C and complete conversion (> 98%) occurring within 3 h. On the other hand, the best overall performing catalyst, the novel complex [RuHCl(iPr-dbfphos)(PPh3)] Ru-2, facilitated full conversion within 1 h leading to an overall turnover frequency of 1009 h−1. Moreover, catalytic activity was observed at temperatures as low as 60 °C. Only CO2 and H2 are observed in the gas phase, with no CO detected. High-resolution mass spectrometry suggests the presence of N-heterocyclic carbene complexes in the reaction mixture.

Differentiation of Ayahuasca Samples According to Preparation Mode and Botanical Varieties Using Metabolomics

ABSTRACT Ayahuasca is a brew traditionally prepared with a mixture of Psychotria viridis leaves and Banisteriopsis caapi vine and has demonstrated therapeutic properties for depression. Knowledge of the brew composition is important to improve the therapeutic potential and decrease side effects if ayahuasca becomes an option for refractory depression treatment. Ultra-high performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HRMS) was applied to analyze 126 ayahuasca samples collected from different ayahuasqueiro groups and geographic origins. We were able to observe a differentiation in the metabolite composition of ayahuasca samples prepared by diverse ayahuasqueiro groups. These samples presented different antioxidant effects based on FRAP and ORAC assays. Exploratory statistical analysis demonstrated a trend of separating the samples according to the religious group. The most important identified compounds for differentiation of the brew prepared by distinct religious groups are glycosylated and/or phenolic compounds. The comparison based on the mode of ayahuasca preparation presented more variability than the comparison based on the botanical variety of B. caapi used. We conclude that ayahuasca samples prepared with “caupuri” or “tucunacá” separately exhibited differences in the analysis of L-glutamate and the metabolism of arginine and proline. This suggests that a possible variation in this pathway could explain the occurrence of swollen stem nodes in “caupuri,” one of the B. caapi varieties.

Online LC-Orbitrap MS method for the rapid molecular characterization of dissolved organic matter.

High-resolution mass spectrometry (HRMS) combined with electrospray ionization (ESI) has been the most useful technique for molecular characterization of dissolved organic matter (DOM) derived from diverse sources. However, the comprehensive detection of DOM composition was hindered by ionization suppression observed in ESI sources. HRMS coupled with liquid chromatography (LC) is a potential tool for comprehensive molecular characterization of DOM. The Suwannee River fulvic acids (SRFAs) and two DOM samples from seawater and refinery wastewater extracted by solid phase extraction (SPE) were analyzed by LC-Orbitrap MS coupled with ESI. The mobile phases, solvent composition, and gradient in the LC-Orbitrap MS analysis were optimized. The number of detected molecular formulae of SRFAs by online LC-Orbitrap MS was significantly increased by approximately 40% compared to direct injection. These additional detected compounds are mainly protein and lignin-like compounds, with a low O/C ratio and high H/C ratio. For the SRFAs, the relative standard deviations (%) of reproducibility are 5.51, 2.33, 7.97, and 1.80 for average O/C, H/C, double bond equivalent, and modified aromaticity index, respectively. This study proposed a simple and rapid method based on LC-Orbitrap MS for an in-depth analysis of the molecular composition of DOM, achieving a remarkable analysis time of only 5 min per sample. The rapid method provides a dependable and efficient approach for the molecular characterization of DOM, thereby advancing our comprehension and investigation of DOM across diverse ecosystems.

Factors affecting the polychlorinated biphenyl signatures in serum of adults living in a highly polluted area in eastern Slovakia

IntroductionOver the years eastern Slovakia has been subject to consistent monitoring of high levels of polychlorinated biphenyls (PCBs) in both the environment and human populations attributed to the former production of PCBs at the Chemko Strážske plant. We aimed to investigate the extent to which dietary habits and residential location could affect the concentrations of PCBs in the blood serum samples of subjects.MethodsWe enrolled 602 adult subjects from eastern Slovakia with an average age of 45.14 (±8.49) years. To determine the concentrations of 21 PCB congeners, we used solid phase extraction along with gas chromatography coupled with high-resolution mass spectrometry. Based on questionnaire data, the assessment of dietary habits and residential location was performed using score calculations and creating a map.Results and discussionThrough principal component analysis, the 20 PCB congeners were classified into three groups: PC1, comprising highly chlorinated PCBs, and PC2 and PC3, consisting primarily of low chlorinated PCBs. Stepwise multivariate regression revealed positive and negative associations between PCB congeners represented by PC1-3 and scores related to the residential location and scores related to food consumption, respectively. We confirmed that levels of PCBs represented by PC1-3 increased with age. The geographical proximity to pollution sources proved to be a key contributing factor to the observed PCB levels in individuals residing in eastern Slovakia.

Highly oxygenated dihydrostilbenoids and flavones from the aerial part of Glycyrrhiza uralensis and their antimicrobial activities

Abstract Background Multidrug-resistant bacteria (MDRB) represent a significant global challenge due to their high mortality rates, substantial economic burden, and rapid spread. Traditional triple or quadruple therapies have demonstrated limited efficacy as a result of increasing drug resistance. Thus, it is urgent to develop novel anti-MDRB drugs with high efficiency and low toxicity. Objectives To isolate and identify the dihydrostilbenoids and flavones from the aerial part of Glycyrrhiza uralensis (Fabaceae) and their antimicrobial activities were screened. Materials and methods The aerial part of G. uralensis was extracted with 75% aqueous EtOH. The crude extract was repeatedly isolated by macroporous resin, silica gel, Sephadex LH-20, C18-MPLC, and MCI-MPLC, which were then purified by semipreparative RP-HPLC to obtain monomer compounds. The structures of the isolates were assigned by a combination of optical rotations, UV spectra, nuclear magnetic resonance, and high-resolution electrospray ionization mass spectrometry, and the absolute configurations of compounds 2, 3, and 7 were further confirmed by electronic circular dichroism calculations. Subsequently, we investigated their antimicrobial activities by the broth microdilution method. Results Seventeen previously undescribed phenolic compounds (1–17) and 26 known analogs (18–43), including dihydrostilbenoids, flavones, and dihydroflavones, were identified from the aerial part of G. uralensis. In vitro, antimicrobial bioassays demonstrated that compound 31 displayed the strongest inhibitory effect against 4 drug-resistant Helicobacter pylori strains (MIC = 2–4 μg/mL), comparable to metronidazole (MIC = 1–32 μg/mL). Additionally, compounds 10, 13, and 15 demonstrated bactericidal activity against Staphylococcus aureus (MIC = 4 μg/mL), while compounds 15 and 22 exhibited inactivation effects against Mycobacterium smegmatis, Enterococcus faecium, and E. faecalis (MIC = 4–8 μg/mL). Conclusions These monomeric compounds with antimicrobial activities were isolated from the aerial parts of G. uralensis, providing valuable insights into the potential anti-MDRB properties of its nonmedicinal parts.

Identification of active ingredients in Naomaitai capsules using high-resolution mass spectrometry unite molecular network analysis and prediction of their action mechanisms.

Although Naomaitai capsule (NMC) is widely used in clinical practice and has a good curative effect for cerebral infarction, its material basis and mechanism of action remain unclear. In this study, ultra-high-performance liquid chromatography (UHPLC) coupled with quadrupole Orbitrap MS technology was used to analyse the in vivo and in vitro components of NMC, and the Global Natural Products Social Molecular Networking website was used to further analyse the components of NMC. Next, systems biology approaches were employed to investigate the mechanism of action of NMC. Finally, molecular docking technology was used to verify the network pharmacological results. In total, 177 compounds were identified in vitro, including 65 terpenoids, 62 flavonoids, 25 organic acids and 11 quinones. 64 compounds were identified in the blood of mice, and the main active components included ginkgolide C, ginkgolide A, ligustilide, tanshinone IIB, olmelin, emodin and puerarin. The main targets in vivo included TP53, SRC, STAT3, PIK3CA and PIK3R1. In conclusion, this study has revealed that NMC acts on multiple targets in the body through various active components, exerting synergistic effects in the treatment of CI. Its mechanism of action may involve inhibiting neuronal apoptosis, oxidative stress and inflammatory responses as well as reducing cerebral vascular permeability and promoting cerebral vascular regeneration.

High-Resolution Tandem Mass Spectrometry for Metabolic Profiling of Ocotea diospyrifolia (Meisn.) Mez Leaves.

Ocotea is an important genusof Lauraceae plant familythat comprises over 400 species, many of which pose challenges in taxonomicdifferentiation due to their complex botanical characteristics. Chemosystematics, and more recently, chemophenetics, have emerged as valuable tools to address these challenges based on their natural products (NPs) composition. O. diospyrifolia (Meisn.) Mez is a poorly studied species with known pharmacological potential. Here, we applied ultra-high performance liquid chromatography coupled with high-resolution tandem mass spectrometry (UHPLC-HRMS) allied to a curated in-house database with all previous isolated NPs from the Ocotea genus (OcoteaDB), gas phase fragmentations reactions, and biosynthesis. The strategy resulted in compounds annotated in confidence levels 2 (n=27), 3 (n=231), and 4 (n=21) according to the Metabolomics Standards Initiative (MSI). Additional annotations based on fragmentation proposals (n=16) were also included. The study revealed that O. diospyrifolia is a great alkaloid producer, even though different lignoids, which also comes from the shikimate pathway, were annotated. Additionally, the flavonoid profile predominantly consists of flavonol glycosides, complementing prior reports. This study provides the first comprehensive chemical profile of O. diospyrifolia leaves, which corroborates the chemotaxonomy of the species, and also contributes to further characterization studies, as the UHPLC-HRMS data is publicly available.

Comparative Metabolomics to Unravel the Biochemical Mechanism Associated with Rancidity in Pearl Millet (Pennisetum glaucum L.)

Despite being a highly nutritious and resilient cereal, pearl millet is not popular among consumers and food industries due to the short shelf-life of flour attributed to rapid rancidity development. The biochemical mechanism underlying rancidity, a complex and quantitative trait, needs to be better understood. The present study aims to elucidate the differential accumulation of metabolites in pearl millet that impact the rancidity process. Metabolite profiling was conducted on ten pearl millet genotypes with varying levels of rancidity—comprising high, low, and medium rancid genotypes—utilizing liquid chromatography and high-resolution mass spectrometry (LC-HRMS) at different accelerated ageing conditions. Through non-targeted metabolomic analysis, crucial metabolites associated with rancidity were identified across various biochemical pathways, including fatty acids, glycerophospholipids, sphingolipids, glycerol lipids, flavonoids, alkaloids, and terpenoids. Notably, metabolites such as fatty aldehydes, fatty alcohols, fatty esters, fatty acyls, fatty esters, and fatty amides were significantly elevated in high rancid genotypes, indicating their involvement in the rancidity process. These fatty acids-related metabolites further break down into saturated and unsaturated fatty acids. Four key fatty acids—stearic, palmitic, linoleic and linolenic acid—were quantified in the ten pearl millet genotypes, confirming their role in rancidity development. This investigation promises novel insights into utilizing metabolomics to understand the biochemical processes and facilitate precision breeding for developing low-rancidity pearl millet lines.

Evaluation of Physiological Activity of Long-Term Ripened Gouda Water Extract

This study investigated peptide changes and their bioactive functions through the long-term ripening of Gouda. Young Gouda (YG), medium Gouda (MG), and extra-sharp Gouda (EG) water extracts were prepared and functional peptides were recognized using liquid chromatography–high-resolution mass spectrometry. Two peptides with ACE-inhibitory effects (IQP and LQP) were identified in YG, while in MG and EG were identified eight (EL, IVP, VP, LPP, VIP, IPP, VPP, and VVPP) and six (EL, YL, VP, IR, YPEL, and DKIHPF) functional peptides, respectively. MG (70.26%) and EG (46.81%) showed stronger antioxidant activity than YG (25.99%) in ABTS (2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic) acid) inhibition, though the DPPH (2,2-diphenyl-1-picrylhydrazyl) inhibition rate decreased with ripening. The antihypertensive effect increased in MG (79.76%) and EG (94.50%) due to ACE-inhibitory peptides. Measurements of inflammatory mRNA expression levels and immunoblotting were conducted to assess the anti-inflammatory properties. MG and EG suppressed the transcription of IL-1β and IL-6 mRNA. Immunoblotting indicated that EG suppressed IκBα phosphorylation to 57%. The enhancement of bioactive function in the water-soluble part of long-term ripened Gouda cheese may have affected identified peptides as well as unknown peptides. Further studies are expected to aid in discovering these novel bioactive peptides.

A systematic evaluation of quenching, extraction and analysis procedures for metabolomics study of the mechanism of QYSLD intervention in A549 cells.

The preparation of cellular metabolomics samples and how to achieve comprehensive coverage of different polar metabolites in cell samples in the analysis pose a challenge for cellular metabolomics. In this study, we optimized a metabolomics protocol based on ultra-high-performance liquid chromatography high-resolution mass spectrometry (UPLC/HRMS) for theextraction and detection of metabolites in A549 cells and exploration of the intervention effect of Qi-Yu-San-Long decoction (QYSLD) on A549 cells. The results indicate that the lowest level of ATP leakage was observed when A549 cells were quenched under liquid nitrogen. MeOH/chloroform/H2O (1:2:1) extraction yielded more chromatographic peaks and excellent reproducibility, and the relative extraction efficiency of most target metabolites was also high. And we optimized thechromatographic separation conditions in both HILIC and RPLC modes, enabling comprehensive detection and analysis of metabolites with varying polarities. Then, we applied the optimized method to UPLC-Q-TOF/MS-based metabolomics of A549 cells to study the mechanism of QYSLD intervention in non-small cell lung cancer (NSCLC). The CCK-8, EdU staining, and cell cycle assay showed that QYSLD inhibited the proliferation of A549 cells by interfering with the cell cycle and blocking them in theG1 phase. A total of 36 differential metabolites associated with the antitumor effects of QYSLD on NSCLC were identified, mainly involving nicotinate and nicotinamide metabolism, sphingolipid metabolism, and glycerophospholipid metabolism. And western blotting confirmed that thechange in 1-methylnicotinamide levels after QYSLD intervention was associated with theinhibition of nicotinamide N-methyltransferase expression in A549 cells.

Contaminant Exposure Profiles Demonstrate Similar Physiological Effects Across Environments Despite Unique Profile Composition in Formosa, Argentina, and Connecticut, USA.

Exposure to environmental contaminants is globally universal. However, communities vary in the specific combination of contaminants to which they are exposed, potentially contributing to variation in human health and creating "locally situated biologies." We investigated how environmental exposures differ across environments by comparing exposure profiles between two contexts that differ markedly across political, economic, and sociocultural factors-Namqom, Formosa, Argentina, and New Haven, Connecticut, United States. We collected infant urine, maternal urine, and human milk samples from mother-infant dyads in Formosa (n = 13) and New Haven (n = 21). We used untargeted liquid chromatography with high-resolution mass spectrometry (LC-HRMS) to annotate environmental contaminants and endogenous metabolites in these samples, and we analyzed the data using exposome-wide association studies (EWAS) followed by pathway enrichment. We found statistically significant differences between the chemical exposure profiles of the Argentinian and US mothers, mostly involving pesticides; however, we observed similarities in the infant urine and human milk environmental contaminant profiles, suggesting that the maternal body may buffer infant exposure through human milk. We also found that infants and mothers were exposed to contaminants that were associated with alterations in amino acid and carbohydrate metabolism. Infants additionally showed alterations in vitamin metabolism, including vitamins B1, B3, and B6. Differences in chemical exposure profiles may be related to structural factors. Despite variation in the composition of exposure profiles between the two study sites, environmental contaminant exposure was associated with similar patterns in human physiology when we considered contaminants comprehensively rather than individually, with implications for metabolic and cardiovascular disease risk as well as infant cognitive development.

Ruthenium Complexes of Phenylbenzothiazole‐Quinoline based Ligands for Selective α‐Olefination of Methylazaarenes

This report describes synthesis of a new ligand (E)‐N‐(4‐(benzo[d]thiazol‐2‐yl)phenyl)‐1‐(quinolin‐2‐yl)methanimine (L1) and its three ruthenium(II) arene complexes with [RuCl2(p‐cymene)]2 (C1), [RuCl2(benzene)]2 (C2), and [RuCl2(hmb)]2 [hmb = hexamethylbenzene] (C3). The new ligand and complexes were characterized with the help of standard spectroscopic and analytical techniques like 1H and 13C{1H} Nuclear Magnetic Resonance (NMR), Fourier transform infrared (FTIR), High‐resolution mass spectrometry (HRMS), UV‐Visible, cyclic voltammetry, and elemental analysis. The structure of ruthenium complex (C1) and its binding mode with ligand were authenticated with the help of single crystal X‐ray diffraction. The ruthenium arene complexes (C1‐C3) were used as a catalyst for the α‐olefination of Methylazaarenes. First, methylazaarenes were reacted with alcohols under optimized reaction conditions to produce α‐olefinated products (up to 66%) selectively. Among the three ruthenium complexes, C1 demonstrated the highest yield of olefinated products with 5 mol% catalyst loading. Finally, selected olefin derivatives were tested for their inhibitory potential towards the aggregation of amyloid‐b‐40 (Aβ40) peptide relevant to Alzheimer’s disease. Overall, these complexes are promising catalysts for organic transformations, and the synthesized α‐olefinated derivatives could have potential applications for the development of therapeutic agents for Alzheimer’s disease.

Discovery of Plasma Lipids as Potential Biomarkers Distinguishing Breast Cancer Patients from Healthy Controls

The development of a sensitive and specific blood test for the early detection of breast cancer is crucial to improve screening and patient outcomes. Existing methods, such as mammography, have limitations, necessitating the exploration of alternative approaches, including circulating factors. Using 598 prospectively collected blood samples, a multivariate plasma-derived lipid biomarker signature was developed that can distinguish healthy control individuals from those with breast cancer. Liquid chromatography with high-resolution and tandem mass spectrometry (LC-MS/MS) was employed to identify lipids for both extracellular vesicle-derived and plasma-derived signatures. For each dataset, we identified a signature of 20 lipids using a robust, statistically rigorous feature selection algorithm based on random forest feature importance applied to cross-validated training samples. Using an ensemble of machine learning models, the plasma 20-lipid signature generated an area under the curve (AUC) of 0.95, sensitivity of 0.91, and specificity of 0.79. The results from this study indicate that lipids extracted from plasma can be used as target analytes in the development of assays to detect the presence of early-stage breast cancer.

Comparative Proteomics of ccRCC Cell Lines to Identify Kidney Cancer Progression Factors.

Clear cell renal cell carcinoma (ccRCC) is the most common type of kidney cancer, accounting for approximately 75% of kidney cancers. The objective of this study was to identify novel progression markers for ccRCC based on proteomics, with the goal of stage determination and early diagnosis of kidney cancer patients. We performed quantitative global proteomics coupled with Stable Isotope Labeling by Amino Acids in Cell Culture (SILAC) and high-resolution tandem mass spectrometry on kidney-derived cells, including HEK-293, 786-O (primary ccRCC), and Caki-1 (metastatic ccRCC) cells, to investigate the novel progression factors of ccRCC. In this study, a total of 1,106 proteins were quantified. The Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were conducted for differentially expressed proteins (DEPs) that were increased in ccRCC cells compared to HEK-293 cells. Ultimately, 99 DEPs including 75 up-regulated and 24 down-regulated proteins, that were significantly altered in both ccRCC cells, were identified. Among DEPs, vimentin was identified as the most significantly changed protein. Its increased expression in ccRCC was verified through immunoblotting in ccRCC cell lines and immunohistochemistry in kidney tumors. From the global proteomics data detected in ccRCC, we propose 99 DEPs including vimentin as progression factors.

Synthesis of an Insulated Oligo(phenylene ethynylene) Dimer Through Cyclodextrin-Based [c2]Daisy Chain Rotaxane

Oligo(phenylene ethynylene)s (OPEs) are π-conjugated systems with promising optical, bioactive, and electrical properties, making them valuable candidates for molecular electronics and biosensors. Controlling the arrangement and orientation of π-conjugated systems is crucial in developing molecular devices. Recently, we developed insulated diarylacetylene dimers using a [c2]daisy chain rotaxane strategy, which brings two cores into close proximity without covalent bonding and shields them with permethylated α-cyclodextrins. Here, we synthesized an insulated OPE dimer using a similar rotaxane strategy to investigate its optical properties. The rotaxane structure and optical properties were evaluated using nuclear magnetic resonance (NMR) spectroscopy, electrospray ionization high-resolution mass spectrometry (ESI-HRMS), and absorption and fluorescence spectroscopy. This study is expected to contribute to the development of optical and electronic materials utilizing OPEs.