The analysis of glycoproteins and the comparison of protein N-glycosylation from different eukaryotic origins requires unbiased and robust analytical workflows. The structural and functional analysis of vertebrate protein N-glycosylation currently depends extensively on bacterial Peptide-N4-(N-acetyl-β-glucosaminyl) asparagine amidases (PNGases), which are indispensable enzymatic tools in releasing

The exact etiology and pathogenesis of CPT are not clear. Quantitative proteomics analysis plays a vital role in disease pathology research. TMT-based proteomics technique were employed to identify and analyze the differentially expressed proteins in the tibia periosteum tissues of CPT.

The COVID-19 pandemic demonstrated the importance of high-throughput analysis for public health. Given the importance of surface viral proteins for interactions with healthy tissue, they are targets of interest for mass spectrometry-based analysis. For that reason, the possibility of detecting and quantifying peptides using a high-throughput technique, laser diode thermal desorption-triple quadrupole

3-Hydroxycarboxylic acids are one of the major components of bacterial lipopolysaccharide (LPS) also known as endotoxin. Endotoxins pose a serious health risk and can seriously damage the internal organs of humans and animals. The presented 3-hydroxycarboxylic acids can be used as environmental markers of endotoxin levels. At the time of preparation of this manuscript no laser mass spectrometry and

Anlotinib is a multi-targets tyrosine kinase inhibitor, which was approved in China for treating several cancer types. Dose individualization based on therapeutic drug monitoring (TDM) is a useful tool to reduce toxicity. However, it’s not convenient for patients to go to hospital for routine TDM via venous blood sampling at a certain time.

Many methods have been reported to produce rare ginsenosides, including heat treatment, acid hydrolysis, alkaline hydrolysis, enzymatic hydrolysis, and microbial transformation. However, the conversion of original ginsenosides to rare ginsenosides in the dual conditions of citric acid and high-pressure steam sterilization pot was rarely reported.

Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) combined with different ionization techniques provides a powerful means to characterize dissolved organic matter (DOM) at the molecular level. Solid-phase extraction (SPE) is currently the most widely utilized method for extracting the DOM, but one-step elution using methanol does not provide a comprehensive picture of DOM. The

Natural urinary peptides profiling are valuable indicators of kidney condition. While front-end separation limits the speed of peptidomic profiling, MS1-based results suffer from limited peptide coverage and specificity. Clinical studies on chronic kidney disease require an effective strategy to balance the trade-off between identification depth and throughput.

Stable isotope approaches are increasingly applied to better understand the cycling of inorganic nitrogen (Ni) forms, key limiting nutrients in terrestrial and aquatic ecosystems. A systematic comparison of the accuracy and precision of the most commonly used methods to analyze δ15N in NO3- and NH4+ and inter-laboratory comparison tests to evaluate the comparability of isotope results between laboratories

RATIONALE The recent progress in microscale isotopic analytical techniques for otoliths has enabled the reconstruction of the experienced water temperature history of fish in every few days resolution by using the stable oxygen isotope ratio (δ18 O) of otoliths. We aimed to improve those techniques and extract the daily δ18 O records of otoliths formed during the juvenile period. METHODS Growth rings

Six of the isomers of aminonitrotoluene (ANT) are 2-amino-3-nitrotoluene (2A3NT), 2A4NT, 2A5NT, 2A6NT, 4A2NT, and 4A3NT. Some of them can be identified by chromatography and spectroscopy. Biochemical transformation of 2,4,6-trinitrotoluene (TNT) and dinitrotoluenes (DNTs) is very complex and ANTs are decomposition products of TNT and DNTs.

Hydroxychloroquine sulfate is effective in the treatment of malaria, autoimmune diseases, and as an antiviral drug. However, unreported impurities are often detected in this drug, which pose a health risk. In this study, the structures of hydroxychloroquine and six unknown impurities were analyzed using ultra-high performance liquid chromatography-quadrupole/time-of-flight tandem mass spectrometry

Ligusticum chuanxiong Hort is a well-known herb medicine that has been widely prescribed to treat cardiovascular diseases in China for hundreds of years. Senkyunolide H (SNH) is one of the major bioactive ingredients extracted from L. chuanxiong, and it displayed neuroprotective effects. To fully understand its mechanism of action, the metabolism needs to be investigated.

The TiO2-Al2O3-SiO2 system is known to be a base for various glass-ceramic materials, which have great practical value in a great deal of modern technologies. Many TiO2-Al2O3-SiO2 materials are synthesized or applied at high temperatures, which justifies the relevance of the present study.

Ion mobility spectrometry (IMS) detects illegal substances and explosives in airports, ports, and customs. This is complicated by false positives caused by overlapping peaks. Shift reagents selectively change ion mobilities through adduction with analyte ions. This discriminates false positives because interferents and illegal substances respond differently to shift reagents.

Annona species are of interest for the isolation of bioactive molecules; however, studies of Annona jahnii Saff. are scarce. The exploration of bioactive metabolites of endophytes isolated from this species is unprecedented and allows the preservation of the host plant, in addition to enabling the discovery of compounds with promising biological activities.

Batatasin III is a biologically active ingredient extracted from Dendrobium scabrilingue, which has been demonstrated to have anticancer activity. To fully understand its action, the present study was performed to investigate the in vitro metabolism of batatasin III using rat and human liver microsomes and hepatocytes.

The gains in sensitivity since 1975 for quadrupole mass spectrometers equipped with atmospheric pressure ionization (API), and in particular triple quadrupole mass spectrometers (QqQ’s) since 1981, have been driven by the needs of the environmental, biomedical, agricultural, and other scientific research, industrial, regulatory, legal, and sporting communities to continually achieve lower limits of

The synthetic β-adrenoreceptor agonist zilpaterol is legitimately used as an animal feed supplement in selected countries due to its known effects on lipolysis and protein biosynthesis. These pharmacological characteristics of zilpaterol have contributed to its classification as doping agent in sport by the World Anti-Doping Agency. However, the use as a feed supplement can lead to residues of the

Gastroesophageal junction adenocarcinoma (GEJA) is a malignant tumor located at the junction of the esophagus and stomach, the incidence of which is increasing year by year, while screening for early biomarkers is limited. Tandem mass tagging (TMT) coupled with liquid chromatography–tandem mass spectrometry (LC/MS/MS) has been used to screen for differential proteins in various cancers.

Electrospray ionization (ESI) and matrix-assisted laser desorption ionization (MALDI) are soft ionization techniques commonly used in mass spectrometry. Although in-source and post-source decays of MALDI have been investigated extensively, the analogous decays of ESI have received little attention. Previous studies regarding the analogous decays of ESI focus on the dissociation of multiply charged

As public interest in health and immunity has increased in recent years, so has the demand for dietary supplements. However, supplements adulterated with illegal drugs and their novel analogues are being sold even as the pharmacological efficacies of these drugs are being advertised. Since the use of these illegal compounds can have serious side effects, they pose a risk to public health. Hence, in

Thermogravimetry (TG) combined with electrospray and atmospheric chemical ionization (ESI+APCI) mass spectrometry (MS) was developed to rapidly characterize thermal decomposition products of synthetic polymers and plastic products. The ESI-based TG-MS method is useful for characterizing thermally labile, nonvolatile, and polar compounds over an extensive mass range; and the APCI-based TG-MS counterpart

Lasalocid (LAS), an ionophore, is used in cattle and poultry farming as feed additive for its antibiotic and growth-promoting properties. Literature on transformation products (TP) resulting from LAS degradation is limited. So far, only hydroxylation is found to occur as the metabolic reaction during the LAS degradation. To investigate potential TPs of LAS, we used electrochemistry (EC) and liver microsome

Propolis has a great diversity in its composition due to numerous factors; therefore, each study is an important contribution to the knoFwledge of its composition and biological action. The objective of this study was to determine the chemical profile and biological activity of propolis produced by Scaptotrigona depilis.

Position-specific 13C/12C ratios within amino acids remain largely unexplored in environmental samples due to methodological limitations. We hypothesized that natural-abundance isotope patterns in serine may serve as a proxy for plant metabolic fluxes including photorespiration. Here we describe an Orbitrap method optimized for the position-specific carbon isotope analysis of serine to test our hypothesis

The anabolic steroid 5α-androst-2-en-17-one (2EN) is sold as a prohormone and has been investigated regarding its potential as a steroidal aromatase inhibitor. The administration of 2EN was detected in a doping control sample in 2015, and investigations into its metabolism allowed for the identification and characterization of three urinary metabolites. Unfortunately, the utility of the main metabolite

Assessing estrogen concentrations in biological systems can provide valuable information on physiological processes, which is crucial for the early diagnosis of many diseases. Because estrogens are present in the human body in low concentrations and in a wide dynamic range, analytical methods with high sensitivity and specificity are required for their determination in complex biological matrices.

The use of sulfur isotopes to study trophic ecology in marine ecosystems has increased in the past decade. Unlike other commonly used isotopes (e.g., carbon), sulfur can better discriminate benthic and pelagic productivity. However, how lipid extraction affects sulfur isotopic values has not been assessed, despite its frequent use to remove lipid effects on δ13C values.

The type and quantity of environmentally problematic disinfection byproducts (DBPs) produced during chlorination of water depend on the natural organic matter and organic contaminants that raw water contains, and on the operational conditions of the drinking water treatment process. There is a need for a fast and quantitative method that determines which DBPs are produced and monitors the chemical

The performance of mass spectrometry (MS) analysis is often affected by the presence of salt ions. To achieve optimal MS detection results, desalting is necessary for samples with high salt concentrations. We report a rapid, low-cost and flexible online desalting method using Nafion-coated sponge. This method is easy to perform and can be implemented to a wide range of customized fluidic systems.

The occurrence of N-heterocyclic carbenes in imidazolium-based ionic liquids has long been discussed, but no spectroscopic evidence has been reported yet due to their transient nature. The insertion of an ionizable acid group into the cation scaffold of an ionic liquid which acts as a charge tag allows for the direct detection of free carbenes by mass spectrometry.

Toluene diisocyanate (TDI) is a highly reactive isocyanate commonly used as a mixture of 2,4- and 2,6- isomers in the production of flexible foams. Exposure to TDI occurs primarily through vapour inhalation in workplaces where TDI is produced or used, but dermal exposure is also possible during some tasks. To ensure workplace safety, accurate monitoring of TDI and toluene diamine (TDA) levels is required

Cesium ions (Cs+) and strontium ions (Sr2+), which enter the human body mainly through drinking water, are an important determinant of health. They are widely distributed on Earth and extremely soluble in water. In order to assist assessment of the drinking safety, it was essential to develop a rapid analytical method for quantification. We have established a 4-mercaptobenzoic acid (MBA)-based matrix-assisted

It is important to remember that performance-enhancing agents such as non-peptide growth hormone secretagogues present a significant risk of abuse. Ibutamoren (MK-0677) is a potent, long-acting, selective non-peptide growth hormone secretagogue that can be taken orally.

The dried roots of Euphorbia kansui L., known as Kansui, are used to treat ascites and edema in traditional Chinese medicine. However, the toxicity of this herb has seriously restricted its clinical application. A unique vinegar-processing method has been used to reduce its toxicity since the time of ancient China. However, the detoxification mechanism underlying such vinegar processing has not been

The analysis of natural variation in light stable isotopes such as carbon (δ13C), nitrogen (δ15N) and sulfur (δ34S) plays an important role in deepening our understanding of ecosystems. To avoid misinterpretation, robust results are required, where pre-treatment steps such as sample homogenization are crucial to guarantee representative samples. The grinding of samples using stainless steel balls in

In 2012, arterolane (ART) in combination with piperaquine received approval in India for the treatment of plasmodium-induced malaria; however, to date, a detailed metabolite identification study of ART has not been reported. Being polar in nature, ART shows early elution on reversed-phase columns which might be the rate-limiting factor of its systematic analytical studies. We have utilized hydrophilic

With the development of the Internet and social network services, the public access to or use of illegal products has been increased via on/offline black markets. Steroids refer to the compounds yielding strong treatment effects on some diseases or muscle building, and are classified as the pharmaceutical compounds that are prohibited for personal use without a prescription. The prohibition is made

Amides are the fundamental units of both peptides and proteins, and also important functional groups of medical chemicals. Investigation of the fragmentation mechanism of amides in the gas phase is scientifically important for structural analysis. However, understanding of this problem is still elusive.

Staurolite is an important mineral that can reveal much about metamorphic processes. For instance, it dominates the Fe–Mg exchange reactions in amphibolite-facies rocks between about 550 and 700°C, and can be also found at suprasolidus conditions. Staurolite contains a variable amount of OH in its structure, whose determination is a key petrological parameter. However, staurolite is often compositionally

Generally, amines form protonated cations ([M + H]+) in positive polarity during electrospray ionization (ESI). However, it was found that large conjugated amines (LCAs) had binary ionization choices of generating either radical cations (M•+) or [M + H]+ during ESI. Investigation on the mechanism would further our understanding of ESI.

Multiplexing ion mobility spectrometry with multiple ion injection pulses was used to achieve a high duty cycle and thus improve the signal-to-noise (S/N) ratio while maintaining high resolving power compared with the traditional single-pulse signal averaging method. Historically, an ion mobility spectrum was reconstructed by various multiplexing methods including Fourier transform ion mobility spectrometry

Ionization by atmospheric pressure gas discharge has been employed for a long time in mass spectrometry. Inductively coupled plasma mass spectrometry is an exemplar, and widely used for elemental analysis. The technique has less uptake in organic mass spectrometry. We describe a simple source design that can be readily implemented in most atmospheric pressure ionization (API) systems and compare its

To assess the suitability of NH4+ as a reagent ion for trace gas analysis by selected ion flow tube mass spectrometry, SIFT-MS, its ion chemistry must be understood. Thus, rate coefficients and product ions for its reactions with typical biogenic molecules and monoterpenes need to be experimentally determined in both helium, He, and nitrogen, N2, carrier gases.

Bear bile powder (BBP) is a widely used traditional Chinese medicine (TCM), and bile acids (BAs) are the main active components in BBP. Due to the scarcity of BBP resources, adulterations often occur in the market. Conventional methods to distinguish them are usually complicated and time-consuming. To enhance effectiveness and accuracy, a rapid and rough analytical method is desperately needed.

Polyhalogenated carbazoles (PHCZs) are dioxin-like compounds that are ubiquitous in the environment. However, their unintentional emissions from industrial sources have received little attention and there is no method available for determination of PHCZs in industrial waste. This research develops a method for determination of PHCZs in industrial waste.

Cucumber, as a popular fruit and vegetable, has tremendously contributed to providing a sufficient and high-quality food supply. However, the cucumber plant metabolites, which may possess potential benefits for human health, were rarely reported. In addition, rapid detection of these metabolites from the complex biological matrix of cucumber samples is a tremendous challenge.

SCO-267 is a potent full agonist of G-protein-coupled receptor 40. As a promising therapeutic agent for type 2 diabetes mellitus, it is necessary to elucidate its metabolite profiles during the stage of drug development for safety considerations.

We studied an aldehyde-labeling reagent, N-{2-[(4-aminophenoxy)methyl]benzyl}-N,N-diethylethanaminium bromide (CAX-A), containing an aniline functional group for the detection of aldehydes with high specificity.

Long-chain monounsaturated α,ω-dicarboxylic acids are important components of the cuticle and suberized cell walls of plants. Identification and quantification of these compounds, which are widespread in environmental samples, can be challenging.

Fully formulated oils (FFOs) are integral to automotive lubrication; however, detailed compositional analysis is challenging due to high levels of chemical complexity. In particular, existing mass spectrometric approaches often target particular FFO components, leading to poor analytical coverage of the overall formulation, with increased overheads and analytical timescales.

Embedding resins are commonly used to facilitate high-resolution sampling for stable isotope analysis but anomalous δ13C values have been observed in some cases. Here we compare the results of microsampling strategies for hand-drilled versus resin-embedded micromilled samples from the same marine shells to assess whether resin contamination is implicated in δ13C spikes. The comparison allows assessment

Cervical cancer is one of the most common malignant tumors in women, and it is essential to explore potential biomarkers such as glycopeptides closely related to cancer in physiological samples of cervical cancer patients. Sample pretreatment is required before direct detection using mass spectrometry because there are certain limitations. Meanwhile, it is still highly desired to promote the functionalization

Due to the special geographical location and climate of China, there are large differences in the chemical composition and content of Paederia scandens (PS) from different origins, which will have a large impact on its efficacy.

The identification and evaluation of novel biomarkers are essential to clinical diagnosis and prognosis of colorectal cancer (CRC). Serum phosphopeptides have been recognized as a potential signature pool for cancers; therefore, we aim to profile the expression of serum phosphopeptides and to evaluate their feasibility in CRC diagnosis.

For disulfide-containing peptides, mass spectrometric analyses are rarely comparably studied between their dithiol and disulfide forms. Persulfide ions afforded from peptides with a disulfide ring are from either an unusual N–Cα bond cleavage or a canonical peptide bond cleavage; their isomeric structures are, however, not identified just from peaks of mass spectra.

We show evidence of cysteinylation on Cys252 of recombinant human p40 subunit of interleukin 12 (IL-12). This was reported in 1996. However, no paper detailing this concept has been published yet. Our paper reports the quantification of Cys252 cysteinylation as well as the full disulfide bridges assignment by nonreducing peptide mapping using mass spectrometry (MS) detection.