Advances in intelligent mass spectrometry data processing technology for in vivo analysis of natural medicines

Natural medicines (NMs) are crucial for treating human diseases. Efficiently characterizing their bioactive components in vivo has been a key focus and challenge in NM research. High-performance liquid chromatography-high-resolution mass spectrometry (HPLC-HRMS) systems offer high sensitivity, resolution, and precision for conducting in vivo analysis of NMs. However, due to the complexity of NMs, conventional data acquisition, mining, and processing techniques often fail to meet the practical needs of in vivo NM analysis. Over the past two decades, intelligent spectral data-processing techniques based on various principles and algorithms have been developed and applied for in vivo NM analysis. Consequently, improvements have been achieved in the overall analytical performance by relying on these techniques without the need to change the instrument hardware. These improvements include enhanced instrument analysis sensitivity, expanded compound analysis coverage, intelligent identification, and characterization of nontargeted in vivo compounds, providing powerful technical means for studying the in vivo metabolism of NMs and screening for pharmacologically active components. This review summarizes the research progress on in vivo analysis strategies for NMs using intelligent MS data processing techniques reported over the past two decades. It discusses differences in compound structures, variations among biological samples, and the application of artificial intelligence (AI) neural network algorithms. Additionally, the review offers insights into the potential of in vivo tracking of NMs, including the screening of bioactive components and the identification of pharmacokinetic markers. The aim is to provide a reference for the integration and development of new technologies and strategies for future in vivo analysis of NMs.

Enhancement of per- and Polyfluoroalkyl Substances (PFAS) quantification on surface waters from marinas in the douro river, Portugal

PFAS, known as "forever" compounds, are prevalent in various environments, including soils and aquatic systems, due to extensive usage. Surface waters in several European countries, especially marinas and ports with high boat traffic, require further study as potential contamination sources. Reliable methods for the extraction and quantification of these emergent compounds are essential. This study aimed to improve an existent solid phase extraction method to analyse marinas and ports' surface waters with variable salinities (2, 9 and 17 PSU). The objectives were to: 1) optimise the solid phase extraction method, considering matrix salinity effects and cross-contaminations, 2) validate the extraction and quantification method of 18 EPA 537.1 PFAS in estuarine surface waters, using the Ultra-High Performance Liquid Chromatography - Quadrupole Time - Of - Flight - Tandem Mass spectrometry, and 3) apply the optimised method for PFAS quantification in three Portuguese marinas. All ICH criteria were successfully validated considering 9 PSU. Limits of quantification ranged from 117.80 ng/L to 385 ng/L, except for PFHpA (645.85 ng/L). PFAS levels (PFOA, HFPO-DA, PFBS, PFHxS and PFOS) were relatively low, reaching a maximum of 0.32 ng/L only for the PFOA. In Freixo marina, total average concentrations were slightly higher (∑PFAS = 1.02 ng/L) when compared to the ones found in Cais da Ribeira Port (∑PFAS = 0.94 ng/L) and Afurada marina (∑PFAS = 0.81 ng/L). PFOS concentrations are below the limit values set by the Environmental Quality Standards (36000 ng/L of PFOS for inland surface water, respectively), similar to other Portuguese river studies. This study enabled the development of a precise and reliable extraction and quantification method to quantify PFAS in estuarine surface waters, particularly from marinas. This method can be readily applied to analyse PFAS in other estuarine samples.

Identification and characterization of GSK-9089 metabolites through high resolution-mass spectrometry based in vitro and in vivo rat biological sample analysis

Estrogen related receptors (ERRs) agonist GSK-9089 (DY-131) reported to pose a potential in increasing exercise endurance. High resolution mass spectrometry (HRMS) based analysis has utmost importance in the detection, identification, or characterization of a molecule including its metabolites in human body. In this study, in vitro metabolism profile of GSK-9089 was investigated after incubation with liver microsomes and S9 fractions. Additionally, in vivo metabolites of the molecule were identified in plasma, urine, and faeces samples of rats. Structures of all the potential metabolites were revealed by employing an in silico tool and HRMS based analysis through data-dependent and data-independent mining strategies. Nine unknown metabolites of GSK-9089 have been identified which were found to be present in a trace amount in in vivo matrices. Most of the in vitro and in vivo phase I metabolites of the molecule were formed after imine bond hydrolysis followed by deamidation, oxidation, and N-oxidation. The molecule underwent phase II metabolism to generate more polar metabolites mainly through glucuronide, sulfate conjugation biotransformation reactions. The in vitro and in vivo metabolites of GSK-9089 could be useful to identify the abuse of this ERRs agonist in the future.

Unraveling the relationship between aroma characteristics and lipid profile of abalone (Haliotis discus hannai) during seasonal fluctuation and thermal processing

Abalone, a highly sought-after aquatic product, possesses significant nutritional value. In this study, the relationship between aroma characteristics and lipid profile of abalone (Haliotis discus hannai) during seasonal fluctuation and thermal processing were profiled via volatolomics and lipidomics. 46 aroma compounds and 371 lipids were identified by HS-SPME-GC-MS and UPLC-Q-Extractive Orbitrap-MS, respectively. Multivariate statistical analysis indicated that carbonyls (aldehydes and ketones) and alcohols were the characteristic aroma compounds of abalone. The fluctuations in the aroma compound and lipid composition of abalone were consistent with the seasonal variation, especially seawater temperature. In addition, based on the correlation analysis, it was found that carbonyls (aldehydes and ketones) and alcohols had a positive correlation with phospholipids (lysophosphatidylethanolamines and lysophosphatidylcholines), while a negative correlation was observed with fatty acyls. These findings suggested that the effect of seasonal variations on the aroma changes of abalone might achieved by modulating the lipids composition of abalone.

Lemon basil seed-derived peptide: Hydrolysis, purification, and its role as a pancreatic lipase inhibitor that reduces adipogenesis by downregulating SREBP-1c and PPAR-γ in 3T3-L1 adipocytes

The purpose of this study is to assess the bioactive peptides derived from the defatted lemon basil seeds hydrolysate (DLSH) for their ability to inhibit pancreatic lipase, decrease intracellular lipid accumulation, and reduce adipogenesis. Response surface methodology (RSM) was employed to optimize trypsin hydrolysis conditions for maximizing lipase inhibitory activity (LI). A hydrolysis time of 387.06 min, a temperature of 49.03°C, and an enzyme concentration of 1.61% w/v, resulted in the highest LI with an IC50 of 368.07 μg/mL. The ultrafiltration of the protein hydrolysate revealed that the fraction below 0.65kDa exhibited the greatest LI potential. Further purification via RP-HPLC identified the Gly-Arg-Ser-Pro-Asp-Thr-His-Ser-Gly (GRSPDTHSG) peptide in the HPLC fraction F1 using mass spectrometry. The peptide was synthesized and demonstrated LI with an IC50 of 0.255 mM through a non-competitive mechanism, with a constant (Ki) of 0.61 mM. Docking studies revealed its binding site with the pancreatic lipase-colipase complex. Additionally, GRSPDTHSG inhibited lipid accumulation in 3T3-L1 cells in a dose-dependent manner without cytotoxic effects. Western blot analysis indicated downregulation of PPAR-γ and SREBP-1c levels under GRSPDTHSG treatment, while an increase in AMPK-α phosphorylation was observed, suggesting a role in regulating cellular lipid metabolism. Overall, GRSPDTHSG demonstrates potential in attenuating lipid absorption and adipogenesis, suggesting a prospective application in functional foods and nutraceuticals.

An integrated approach for studying the metabolic profiling of herbal medicine in mice using high-resolution mass spectrometry and metabolomics data processing tools

Analysis of exposure to traditional Chinese medicine (TCM) in vivo based on mass spectrometry is helpful for the screening of effective ingredients of TCM and the development of new drugs. The method of screening biomarkers through metabolomics technology is a nontargeted research method to explore the differential components between two sets of biological samples. By taking this advantage, this study aims to takes Forsythia suspensa, which is a TCM also known as Lian Qiao (LQ), as the research object and to study its in vivo exposure by using metabolomics technology. By comparing the significant differences between biological samples before and after administration, it could be focused on the components that were significantly upregulated, where a complete set of analysis strategies for nontargeted TCM in vivo exposure mass spectrometry was established. Furthermore, the threshold parameters for peak extraction, parameter selection during statistical data analysis, and sample concentration multiples in this method have also been optimized. More interestingly, by using the established analysis strategy, we found 393 LQ-related chemical components in mice after administration, including 102 prototypes and 291 LQ-related metabolites, and plotted their metabolic profiles in vivo. In short, this study has obtained a complete mass spectrum of LQ exposure in mice in vivo for the first time, which provides a reference for research on the active ingredients of LQ in vivo. More importantly, compared with other methods, the analysis strategy of nontargeted exposure of TCM in vivo-based mass spectrometry, constructed by using this research method, has good universality and does not require self-developed postprocessing software. It is worth mentioning that, for the identification and characterization of trace amounts of metabolites in vivo, this analysis strategy has no discrimination and has a detection capability similar to that of highly exposed components.

Proteomic analyses of venom from a Spider Hawk, Pepsis decorata

Background

The composition of the venom from solitary wasps is poorly known, although these animals are considered sources of bioactive substances. Until the present moment, there is only one proteomic characterization of the venom of wasps of the family Pompilidae and this is the first proteomic characterization for the genus Pepsis.

Methods

To elucidate the components of Pepsis decorata venom, the present work sought to identify proteins using four different experimental conditions, namely: (A) crude venom; (B) reduced and alkylated venom; (C) trypsin-digested reduced and alkylated venom, and; (D) chymotrypsin-digested reduced and alkylated venom. Furthermore, three different mass spectrometers were used (Ion Trap-Time of Flight, Quadrupole-Time of Flight, and Linear Triple Quadruple).

Results

Proteomics analysis revealed the existence of different enzymes related to the insect's physiology in the venom composition. Besides toxins, angiotensin-converting enzyme (ACE), hyaluronidase, and Kunitz-type inhibitors were also identified.

Conclusion

The data showed that the venom of Pepsis decorata is mostly composed of proteins involved in the metabolism of arthropods, as occurs in parasitic wasps, although some classical toxins were recorded, and among them, for the first time, ACE was found in the venom of solitary wasps. This integrative approach expanded the range of compounds identified in protein analyses, proving to be efficient in the proteomic characterization of little-known species. It is our understanding that the current work will provide a solid base for future studies dealing with other Hymenoptera venoms.

Nutritional value of different parts from sea eel (Astroconger myriaster) determined by untargeted-lipidomic approach

With the diversity of consumer demands for healthy food, stricter requirements have been put forward for the product quality of sea eel (Astroconger myriaster). From the common experience, remarkable differences could be observed between different parts of the sea eel. The textures, basic nutritional compositions, and lipid compositions from seven parts of sea eel were investigated to reach a comprehensive evaluation of the nutritional value. Sea eel was high-fat fish which contained 21.65% to 22.84% crude fat from part one to part seven. The seventh segment exhibited a lower moisture content (51.32%) and higher contents of protein (22.76%), ash (2.46%), carbohydrate (0.80%). The third and fourth parts remained higher hardness and good water-holding capacity. Sea eel had sixteen fatty acids, and the tail possessed a higher proportion of n - 3/n - 6 polyunsaturated fatty acids. Twenty-seven lipid species were determined in sea eel, and highly unsaturated fatty acids mainly stemmed from triglycerides, while saturated fatty acids mainly existed as diglycerides. Section six and seven were primarily diglycerides and monoglycerides. According to the characteristics of different parts, it can provide support for standardized segmentation of sea eel and quality control of different parts.

Metabolite Identification of Isopropoxy Benzene Guanidine in Rat Liver Microsomes by Using UHPLC-Q-TOF-MS/MS

Isopropoxy benzene guanidine (IBG) is a guanidine derivative with antibacterial activity against multidrug-resistant bacteria. A few studies have revealed the metabolism of IBG in animals. The aim of the current study was to identify potential metabolic pathways and metabolites of IBG. The detection and characterization of metabolites were performed with high-performance liquid chromatography tandem mass spectrometry (UHPLC-Q-TOF-MS/MS). Seven metabolites were identified from the microsomal incubated samples by using the UHPLC-Q-TOF-MS/MS system. The metabolic pathways of IBG in the rat liver microsomes involved O-dealkylation, oxygenation, cyclization, and hydrolysis. Hydroxylation was the main metabolic pathway of IBG in the liver microsomes. This research investigated the in vitro metabolism of IBG to provide a basis for the further pharmacology and toxicology of this compound.

Comprehensive Metabolic Profiling of Euphorbiasteroid in Rats by Integrating UPLC-Q/TOF-MS and NMR as Well as Microbial Biotransformation

Euphorbiasteroid, a lathyrane-type diterpene from Euphorbiae semen (the seeds of Euphorbia lathyris L.), has been shown to have a variety of pharmacological effects such as anti-tumor and anti-obesity. This study aims to investigate the metabolic profiles of euphorbiasteroid in rats and rat liver microsomes (RLMs) and Cunninghamella elegans bio-110930 by integrating ultra-performance liquid chromatography-quadrupole time-of-flight-mass spectrometry (UPLC-Q/TOF-MS), UNIFI software, and NMR techniques. A total of 31 metabolites were identified in rats. Twelve metabolites (M1–M5, M8, M12–M13, M16, M24–M25, and M29) were matched to the metabolites obtained by RLMs incubation and the microbial transformation of C. elegans bio-110930 and their structures were exactly determined through analysis of NMR spectroscopic data. In addition, the metabolic pathways of euphorbiasteroid were then clarified, mainly including hydroxylation, hydrolysis, oxygenation, sulfonation, and glycosylation. Finally, three metabolites, M3 (20-hydroxyl euphorbiasteroid), M24 (epoxylathyrol) and M25 (15-deacetyl euphorbiasteroid), showed significant cytotoxicity against four human cell lines with IC₅₀ values from 3.60 μM to 40.74 μM. This is the first systematic investigation into the in vivo metabolic pathways of euphorbiasteroid and the cytotoxicity of its metabolites, which will be beneficial for better predicting the metabolism profile of euphorbiasteroid in humans and understanding its possible toxic material basis.

A Comprehensive Study to Identify Major Metabolites of an Amoxicillin-Sulbactam Hybrid Molecule in Rats and Its Metabolic Pathway Using UPLC-Q-TOF-MS/MS

Amoxicillin and sulbactam are widely used compound drugs in animal food. The amoxicillin-sulbactam hybrid molecule can achieve better curative effects through the combination of the two drugs. However, its pharmacokinetic behavior needs to be explored. In this study, a randomized crossover experiment was performed to investigate the metabolism of the novel amoxicillin-sulbactam hybrid molecule in rats after gastric administration. Ultrahigh performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS) was used to isolate and to identify the metabolites in rats. Amoxicillin, amoxicilloic acid, amoxicillin diketopiperazine, and sulbactam were eventually detected in the plasma, liver, urine, and kidneys; no hybrid molecules and their metabolites were detected in feces. The in vivo metabolism results showed that the hybrid molecule was absorbed into the body in the intestine, producing amoxicillin and sulbactam, then amoxicillin was partially metabolized to amoxicilloic acid and amoxicillin diketopiperazine, which are eventually excreted in the urine by the kidneys. In this study, four major metabolites of the amoxicillin-sulbactam hybrid molecule were identified and their metabolic pathways were speculated, which provided scientific data for understanding the metabolism of the hybrid molecule and for its clinical rational use.

Recent Advances in Analytical Methods for Determination of Polyphenols in Tea: A Comprehensive Review

Polyphenols, the most abundant components in tea, determine the quality and health function of tea. The analysis of polyphenols in tea is a topic of increasing interest. However, the complexity of the tea matrix, the wide variety of teas, and the difference in determination purposes puts forward higher requirements for the detection of tea polyphenols. Many efforts have been made to provide a highly sensitive and selective analytical method for the determination and characterization of tea polyphenols. In order to provide new insight for the further development of polyphenols in tea, in the present review we summarize the recent literature for the detection of tea polyphenols from the perspectives of determining total polyphenols and individual polyphenols in tea. There are a variety of methods for the analysis of total tea polyphenols, which range from the traditional titration method, to the widely used spectrophotometry based on the color reaction of Folin–Ciocalteu, and then to the current electrochemical sensor for rapid on-site detection. Additionally, the application of improved liquid chromatography (LC) and high-resolution mass spectrometry (HRMS) were emphasized for the simultaneous determination of multiple polyphenols and the identification of novel polyphenols. Finally, a brief outline of future development trends are discussed.

LC-Q-TOF-MS/MS detection of food flavonoids: principle, methodology, and applications

Flavonoids have been attracting increasing research interest because of their multiple health promoting effects. However, many flavonoids with similar structures are present in foods, often at low concentrations, which increases the difficulty of their separation and identification. Liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (LC-Q-TOF-MS/MS) has become one of the most widely used techniques for flavonoid detection. LC-Q-TOF-MS/MS can achieve highly efficient separation by LC; it also provides structural information regarding flavonoids by Q-TOF-MS/MS. This review presents a comprehensive summary of the scientific principles and detailed methodologies (e.g., qualitative determination, quantitative determination, and data processing) of LC-Q-TOF-MS/MS specifically for food flavonoids. It also discusses the recent applications of LC-Q-TOF-MS/MS in determination of flavonoid types and contents in agricultural products, changes in their structures and contents during food processing, and metabolism in vivo after consumption. Moreover, it proposes necessary technological improvements and potential applications. This review would facilitate the scientific understanding of theory and technique of LC-Q-TOF-MS/MS for flavonoid detection, and promote its applications in food and health industry.

Liquid Chromatography-Mass Spectrometry for Clinical Metabolomics: An Overview

Metabolomics is a discipline that offers a comprehensive analysis of metabolites in biological samples. In the last decades, the notable evolution in liquid chromatography and mass spectrometry technologies has driven an exponential progress in LC-MS-based metabolomics. Targeted and untargeted metabolomics strategies are important tools in health and medical science, especially in the study of disease-related biomarkers, drug discovery and development, toxicology, diet, physical exercise, and precision medicine. Clinical and biological problems can now be understood in terms of metabolic phenotyping. This overview highlights the current approaches to LC-MS-based metabolomics analysis and its applications in the clinical research.

A New Workflow for Drug Metabolite Profiling by Utilizing Advanced Tribrid Mass Spectrometry and Data-Processing Techniques

Drug metabolite profiling utilizes liquid chromatography with tandem mass spectrometry (LC/MS/MS) to acquire ample information for metabolite identification and structural elucidation. However, there are still challenges in detecting and characterizing all potential metabolites that can be masked by a high biological background, especially the unknown and uncommon ones. In this work, a novel metabolite profiling workflow was established on a platform using a state-of-the-art tribrid high-resolution mass spectrometry (HRMS) system. Primarily, an instrumental method was developed based on the novel design of the tribrid system that facilitates in-depth MSⁿ scans with two fragmentation devices. Additionally, different advanced data acquisition techniques were assessed and compared, and automatic background exclusion and deep-scan approaches were adopted to promote assay efficiency and metabolite coverage. Finally, different data-analysis techniques were explored to fully extract metabolite data from the information-rich MS/MS data sets. Overall, a workflow combining tribrid mass spectrometry and advanced acquisition methodology has been developed for metabolite characterization in drug discovery and development. It maximizes the tribrid HRMS platform's utility and enhances the coverage, efficiency, quality, and speed of metabolite profiling assays.

IGHG1 induces EMT in gastric cancer cells by regulating TGF-β/SMAD3 signaling pathway

Objective: Gastric cancer is one of the most common malignant tumors in the world. IGHG1 is a differentially expressed protein screened out in gastric cancer in the early stage of the subject group. This topic explores the expression of IGHG1 in gastric cancer and the effect of IGHG1 on the proliferation, migration, invasion and EMT of gastric cancer SGC7901 cells and its mechanism of action.

Methods: Twenty cases of gastric cancer were purified by laser Capture Microdissection. The isotopic tags for relative and absolute quantification was used to label the proteins, and then analyzed and identified them by quantitative proteomics. Immunohistochemical staining method was used to detect the expression of IGHG1 protein in gastric cancer tissues. Western blot was used to detect the expression of IGHG1 in gastric cancer cells. The MTT and Petri dish clone formation experiment analyzed the effect of low expression of IGHG1 on the proliferation of SGC7901 cells. Scratch test and Transwell migration and invasion test to observe the effect of low expression of IGHG1 on the migration and invasion of SGC7901 cells. Western blot was used to detect the effect of low expression of IGHG1 on the expression of EMT-related proteins.

Results: 243 proteins related to gastric mucosal lesions were preliminarily identified. We found that IGHG1 is highly expressed in gastric cancer tissues compared with normal control tissues. IGHG1 promotes the proliferation, migration and invasion of gastric cancer cells. Compared with the control group, the expression of EMT-related proteins Vimentin, N-cadherin, TGF-β, P-SMAD3 was decreased and the expression of E-cadherin was increased after IGHG1 low expression.

Conclusions: IGHG1 induces EMT in SGC7901 cells by regulating the TGF-β/SMAD3 signaling pathway.

Metabolic profiling of RB-2 and RB-4, two analogs of polyacetylene from Bupleurum

RB-2 and RB-4 are two structural analogs of polyacetylene from Radix Bupleuri that show antidepressant effects. However, no metabolic data are available to elucidate their systemic homeostasis. Mass spectrometry combined with liver microsomes and recombinant drug-metabolizing enzymes were performed to profile the biotransformations of RB-2/RB-4 in vitro and in vivo. Oxidation should be the major metabolic pathways for them in phase I, while CYP2C9 and CYP2E1 was the major contributor. In phase II, conjugational groups usually combined with the metabolites from phase I. This study provides an important reference basis for the safety evaluation and rational application of RB-2/RB-4.

Metabolic stability studies of lead compounds supported by separation techniques and chemometrics analysis

With metabolism being one of the main routes of drug elimination from the body (accounting for removal of around 75% of known drugs), it is crucial to understand and study metabolic stability of drug candidates. Metabolically unstable compounds are uncomfortable to administer (requiring repetitive dosage during therapy), while overly stable drugs increase risk of adverse drug reactions. Additionally, biotransformation reactions can lead to formation of toxic or pharmacologically active metabolites (either less-active than parent drug, or even with different action). There were numerous approaches in estimating metabolic stability, including in vitro, in vivo, in silico, and high-throughput screening to name a few. This review aims at describing separation techniques used in in vitro metabolic stability estimation, as well as chemometric techniques allowing for creation of predictive models which enable high-throughput screening approach for estimation of metabolic stability. With a very low rate of drug approval, it is important to understand in silico methods that aim at supporting classical in vitro approach. Predictive models that allow assessment of certain biological properties of drug candidates allow for cutting not only cost, but also time required to synthesize compounds predicted to be unstable or inactive by in silico models.

Identification of the absorptive constituents and their metabolites in vivo of Ziziphi Spinosae Semen by UPLC-ESI-Q-TOF-MS/MS

In this research, ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC-ESI-Q-TOF-MS/MS) was used for detection and identification of the absorptive constituents and their metabolites in rat plasma, urine and feces following oral administration of Ziziphi Spinosae Semen alcohol extract. After structure elucidation, a total of 12 compounds in rat plasma, comprising seven prototypes and five metabolites, 28 compounds in urine, comprising 17 prototypes and 11 metabolites, and 23 compounds in feces, comrpising 17 prototypes and six metabolites, have been tentatively identified by comparison with standard compounds and reference literature information. To the best of our knowledge, this is the first comprehensive and systematical metabolic study on the seed. Mostly importantly, we propose that gastric acid could convert jujubosides into an absorbable form of ebelin lactone oligosaccharides, which may be responsible for the low bioavailability and specific bioactivities of these compounds. Additionally, we deduced that the absorption site of ebelin lactone oligosaccharides is located in the stomach, and that the ebelin lactone form of jujubosides may be more suitable for absorption than its hydrolysis product. Our investigation will be helpful to narrow the scope for potentially active ingredients of the seed, and pave the way for determination of the pharmacological mechanism of the seed.

Sonochemical degradation of benzenesulfonic acid in aqueous medium

Degradation of benzenesulfonic acid (BSA), the simplest aromatic sulfonic acid with extreme industrial importantance, by sonochemically generated hydroxyl radical (OH) have been thoroughly investigated. A reasonable reduction (∼50%) in the total organic carbon (TOC) was achieved only after prolonged irradiation (∼275 min, 350 kHz) of ultrasound, although a short irradiation of less than an hour is enough to degrade significant amount of BSA. The degradation efficiency of ultrasound has been reduced in lower and extremely higher frequencies, and upon increasing the pH. An irregular, but continuous, release of sulfate ions was also observed. Further, the release of protons upon the oxidation of BSA consistently reduces the experimental pH to nearly 2. High resolution mass spectrometric (HRMS) analyses reveals the formation of a number of aromatic intermediates, including three mono (I_a-c) and two di (II_a&b) hydroxylated BSA derivatives as the key products in the initial stages of the reaction. Pulse radiolysis studies revealed the generation of hydroxycyclohexadienyl-type radicals, characterized by absorption bands at 320 nm (k₂ = (7.16 ± 0.04) × 10⁹ M^-1 s^-1) and 380 nm, as the immediate intermediates of the reaction. The mechanism(s) leading to the degradation of BSA under sonolytic irradiation conditions along with the effect of various factors, such as the ultrasound frequency and reaction pH, have been explained in detail. The valuable mechanistic aspects obtained from our pulse radiolysis and HRMS studies are essential for the proper implementation of sonochemical techniques into real water purification process and, thus, receives extreme environmental relevance.

Precision Nutrition and Childhood Obesity: A Scoping Review

Environmental exposures such as nutrition during life stages with high developmental plasticity—in particular, the in utero period, infancy, childhood, and puberty—may have long-lasting influences on risk of chronic diseases, including obesity-related conditions that manifest as early as childhood. Yet, specific mechanisms underlying these relationships remain unclear. Here, we consider the study of ‘omics mechanisms, including nutrigenomics, epigenetics/epigenomics, and metabolomics, within a life course epidemiological framework to accomplish three objectives. First, we carried out a scoping review of population-based literature with a focus on studies that include ‘omics analyses during three sensitive periods during early life: in utero, infancy, and childhood. We elected to conduct a scoping review because the application of multi-‘omics and/or precision nutrition in childhood obesity prevention and treatment is relatively recent, and identifying knowledge gaps can expedite future research. Second, concomitant with the literature review, we discuss the relevance and plausibility of biological mechanisms that may underlie early origins of childhood obesity identified by studies to date. Finally, we identify current research limitations and future opportunities for application of multi-‘omics in precision nutrition/health practice.

A feasible strategy based on isotopic fine structures to enhance the reliability of metabolite identification by Fourier transform ion cyclotron resonance mass spectrometry

RATIONALE

In the process of the identification of unknown metabolites, the most important thing is to determine their real chemical formulae according to the accurate masses which are determined by high-resolution mass spectrometry. However, high mass accuracy alone is not enough to exclude false candidates. Use of isotopic fine structures (IFSs) derived from Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) as a single further constraint could decisively determine the molecular formulae for unknown metabolites.

METHODS

Gastrodin, an active constituent from Gastrodia elata Bl., which can penetrate through the blood-brain barrier and rapidly decompose to p-hydroxybenzyl alcohol in the brain, was selected as a model drug. The accurate masses, possible chemical formulae and IFSs of its metabolites in rat plasma were acquired using FT-ICR MS.

RESULTS

Besides gastrodin, a total of eight metabolites including two phase I and six phase II metabolites were detected. Their chemical formulae were decisively determined by IFSs. Furthermore, their chemical structures were identified by comparing their fragment ions with those of gastrodin. Results indicated the metabolic pathways of gastrodin in rats including deglycosylation, oxidation, glucuronidation, sulfate conjugation and glycine conjugation.

CONCLUSIONS

It is demonstrated that IFSs are effective in unambiguous determination of chemical formulae of metabolites. It could be used as a feasible strategy to enhance the reliability of metabolite identification in drug metabolism studies.

Drug Metabolite Cluster-Based Data-Mining Method for Comprehensive Metabolism Study of 5-hydroxy-6,7,3',4'-tetramethoxyflavone in Rats

The screening of drug metabolites in biological matrixes and structural characterization based on product ion spectra is among the most important, but also the most challenging due to the significant interferences from endogenous species. Traditionally, metabolite detection is accomplished primarily on the basis of predicted molecular masses or fragmentation patterns of prototype drug metabolites using ultra-high performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-HRMS). Although classical techniques are well-suited for achieving the partial characterization of prototype drug metabolites, there is a pressing need for a strategy to enable comprehensive drug metabolism depiction. Therefore, we present drug metabolite clusters (DMCs), different from, but complementary to, traditional approaches for mining the information regarding drugs and their metabolites on the basis of raw, processed, or identified tandem mass spectrometry (MS/MS) data. In this paper, we describe a DMC-based data-mining method for the metabolite identification of 5-hydroxy-6,7,3′,4′-tetramethoxyflavone (HTF), a typical hydroxylated-polymethoxyflavonoid (OH-PMF), which addressed the challenge of creating a thorough metabolic profile. Consequently, eight primary metabolism clusters, sixteen secondary metabolism clusters, and five tertiary metabolism clusters were proposed and 106 metabolites (19 potential metabolites included) were detected and identified positively and tentatively. These metabolites were presumed to generate through oxidation (mono-oxidation, di-oxidation), methylation, demethylation, methoxylation, glucuronidation, sulfation, ring cleavage, and their composite reactions. In conclusion, our study expounded drug metabolites in rats and provided a reference for further research on therapeutic material basis and the mechanism of drugs.

Quadrupole Time-of-Flight Mass Spectrometry: A Paradigm Shift in Toxicology Screening Applications

The screening of biological samples for the presence of illicit or legal substances is an important frontline tool in both clinical and forensic toxicology. In the clinical setting, drug screening is a useful tool for the clinician in improving patient care and guiding treatment. Analytical approaches for the screening of drugs in biological samples are extensive and well documented, though many rapid screening techniques often lack appropriate sensitivity and specificity, requiring careful clinical interpretation. The continuous emergence of new psychoactive substances presents a considerable analytical challenge in maintaining up-to-date methods for the detection of relevant drugs. Adapting and validating methods for the detection of new substances can be a complicated and costly undertaking. There is also a considerable lag time between the emergence of new drugs and the release of commercial assays for detection. Quadrupole time-of-flight mass spectrometry (Q-TOF-MS) has gained considerable attention over the last decade as an analytical technique that is capable of meeting the challenges of a rapidly changing drug landscape. Exhibiting both high sensitivity and specificity in drug detection, Q-TOF-MS also allows methods to be rapidly updated for newly emerging psychoactive agents. The coupling of Q-TOF-MS with techniques such as liquid or gas chromatography can provide both rapid and comprehensive screening solutions that are gaining popularity in the clinical laboratory setting.

Improving Lipidomic Coverage Using UPLC-ESI-Q-TOF-MS for Marine Shellfish by Optimizing the Mobile Phase and Resuspension Solvents

Reversed-phase ultrahigh-performance-liquid chromatography-mass spectrometry (UPLC-MS) is the typical method for the lipidomic analysis of most of biological samples, which was rarely used for the comprehensive lipidomic analysis of marine shellfish. Thus, a range of columns, modifiers, and resuspension solvents were evaluated using UPLC-electrospray ionization-quadrupole time-of-flight-MS to facilitate the ionization efficiency in both the positive and negative electrospray ionization (ESI(+)/(-)) modes for abalone lipids. Optimal lipidomic coverage was acquired with 10 mM ammonium formate in both ESI(+)/(-) modes. The selected resuspension solvents also influenced ionization efficiency through the matrix effect, and resuspension in methanol enhanced the signal intensities by reducing ion suppression. Because of the higher glycerophospholipid content in shellfish, bridged ethylene hybrid C₈ columns showed clear advantages over charged surface hybrid C₁₈ columns. A series of glycerophospholipids, lyso-glycerophospholipids, glycerolipids, and fatty acids in different shellfish can be annotated and semiquantified in one injection by the optimized method.

Intestinal mucosal metabolites-guided detection of trace-level ginkgo biloba extract metabolome

The characterization of metabolome for poorly absorptive natural medicines is challenging. Previous identification strategy often relies on nontargeted scanning biological samples from animals administered with natural medicines in a data-dependent acquisition (DDA) mode by LC-MS/MS. Substances that displayed significant increases following drug administration are thus assigned as potential metabolites. The accurate m/z of precursors and the corresponding MS/MS fragment ions are used to match with herbal ingredients and to infer possible metabolic reactions. Nevertheless, the low concentration of these metabolites within complex biological matrices has often hampered the detection. Herein we developed a strategy termed intestinal mucosal metabolome-guided detection (IMMD) to tackle this challenge using ginkgo biloba (GBE) as an example. The rationale is that poorly absorptive natural products are usually concentrated and extensively metabolized by enterocytes before they enter the blood stream and distribute to other organs. Therefore, we firstly identified the metabolites from intestinal mucosa of GBE-treated rats, and then used the identified intestinal mucosal GBE metabolome as targeted repository for MRM analysis. The presences of these metabolites were subsequently examined in rat plasma, liver and brain. The resultant GBE metabolome showed significantly improved coverage with 39, 45 and 6 metabolites identified in plasma, liver and brain compared to 22, 16 and 0 metabolites from the corresponding regions via the DDA-based strategy. In addition, we integrated the previously reported nontargeted diagnostic ion network analysis to facilitate the characterization of GBE components, and a chemicalome-metabolome matching approach (CMMA) to assist the identity assignment of GBE metabolome with IMMD. Combinatorially, we establish a multi-faceted platform to streamline the workflow of metabolome characterization for herbal medicines of low bioavailability. The metabolome information is expected to shed light on the elucidation of metabolic pathways for natural products, and the underlying mechanisms of their biological efficacies.

In silico, in vitro and in vivo metabolite identification of brexpiprazole using ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry

RATIONALE

Brexpiprazole is a novel serotonin-dopamine activity modulator approved by the USFDA in July 2015 for the treatment of schizophrenia and as an adjunctive therapy with other antidepressants for major depressive disorder in adults. However, limited numbers of metabolites are reported in the literature for brexpiprazole. Our prime intent behind this study is to revisit metabolite profiling of brexpiprazole and to identify and characterize all possible in vitro and in vivo metabolites.

METHODS

Firstly, the site of metabolism for brexpiprazole was predicted by a Xenosite web predictor model. Secondly, in vitro metabolite profiling was performed by incubating the drug individually with rat liver microsomes, human liver microsomes and rat S9 fraction at 37°C for 1 h in incubator shaker. Finally, for in vivo metabolite identification, a 50 mg kg^-1 dose of brexpiprazole was administered to male Sprague-Dawley rats and the presence of various metabolites was confirmed in rat plasma, urine and feces.

RESULTS

The predicted atomic site of metabolism was obtained as a color gradient by the Xenosite web predictor tool and, from this study, probable metabolites were listed. In total, 14 phase I and 2 phase II metabolites were identified and characterized in the in vitro and in vivo matrices using ultra-high-performance liquid chromatography/quadrupole time-of-flight tandem mass spectrometry (UHPLC/QTOF-MS/MS). The majority of metabolites were found in the sample incubated with human liver microsomes and in rat urine, while in the other matrices only a few metabolites were detected.

CONCLUSIONS

All the 16 metabolites were identified and characterized using UHPLC/QTOF-MS/MS. The study revealed that brexpiprazole is metabolized via hydroxylation, glucuronidation, S-oxidation, N-oxidation, dioxidation, oxidative deamination, N-dealkylation, etc.

Metabolic profiling analysis of corilagin in vivo and in vitro using high-performance liquid chromatography quadrupole time-of-flight mass spectrometry

Corilagin is an Ellagitannin with favorable pharmacological activities. But there was no report regarding the metabolism of corilagin in vitro or in vivo. In this study, the metabolic profile of corilagin in rats as well as in rat intestinal bacteria and liver microsomes incubation system in vitro were investigated comprehensively for the first time. Consequently, with the aid of sensitive HPLC-Q-TOF-MS/MS, corilagin and its twenty-four metabolites (fourteen phase II conjugate metabolites of corilagin, three hydrolyzed metabolites EA, GA, M3 and their seven derived metabolites) were absolutely or tentatively identified in rat biological samples (urine, feces, plasma and tissues) after oral administration of corilagin. In vitro, the three hydrolyzed metabolites were identified in rat intestinal microflora and liver microsomes. These results demonstrated that corilagin itself not only could underwent extensive phase II metabolism in rats, but also could underwent hydrolysis reaction in rats as well as in rat intestinal bacteria and liver microsomes in vitro. This study is first report to identify phase II conjugate metabolites (except mono-methylate conjugated metabolites) of pure Ellagitannin and distribution of these metabolites in vivo. In addition, clear, detailed metabolic pathways of corilagin were shown to involve hydrolysis, methylation, glycosylation, reduction, glucuronidation and sulfation.

An LC-MS-based lipidomics pre-processing framework underpins rapid hypothesis generation towards CHO systems biotechnology

INTRODUCTION

Given a raw LC-MS dataset, it is often required to rapidly generate initial hypotheses, in conjunction with other 'omics' datasets, without time-consuming lipid verifications. Furthermore, for meta-analysis of many datasets, it may be impractical to conduct exhaustive confirmatory analyses. In other cases, samples for validation may be difficult to obtain, replicate or maintain. Thus, it is critical that the computational identification of lipids is of appropriate accuracy, coverage, and unbiased by a researcher's experience and prior knowledge.

OBJECTIVES

We aim to prescribe a systematic framework for lipid identifications, without usage of their characteristic retention-time by fully exploiting their underlying mass features.

RESULTS

Initially, a hybrid technique, for deducing both common and distinctive daughter ions, is used to infer parent lipids from deconvoluted spectra. This is followed by parent confirmation using basic knowledge of their preferred product ions. Using the framework, we could achieve an accuracy of ~ 80% by correctly identified 101 species from 18 classes in Chinese hamster ovary (CHO) cells. The resulting inferences could explain the recombinant-producing capability of CHO-SH87 cells, compared to non-producing CHO-K1 cells. For comparison, a XCMS-based study of the same dataset, guided by a user's ad-hoc knowledge, identified less than 60 species of 12 classes from thousands of possibilities.

CONCLUSION

We describe a systematic LC-MS-based framework that identifies lipids for rapid hypothesis generation.

Comparing the fragmentation reactions of protonated cyclic indolyl α-amino esters in quadrupole/orbitrap and quadrupole time-of-flight mass spectrometers

RATIONALE

The comparative study of higher-energy collisional dissociation (HCD) and collision-induced dissociation (CID) mechanisms for protonated cyclic indolyl α-amino esters in quadrupole/orbitrap (Q/Orbitrap) and quadrupole time-of-flight (QTOF) mass spectrometers, respectively, is helpful to study the structures and properties of biologically active indole derivatives using tandem mass spectrometry (MS/MS) technology.

METHODS

HCD and CID experiments were carried out using electrospray ionization Q/Orbitrap MS and QTOFMS in positive ion mode, respectively. Only the labile hydrogens were exchanged with deuterium in hydrogen/deuterium exchange (HDX) experiments and only the aromatic indole C-H hydrogens were substituted with deuterium in regiospecific hydrogen-deuterium labeling experiments. Theoretical calculations were carried out using the density functional theory (DFT) method at the B3LYP level with the 6-311G(d,p) basis set in the Gaussian 03 package of programs.

RESULTS

In Q/Orbitrap MS/MS, when the added proton on the N⁸ position of protonated cyclic indolyl α-amino esters migrated in a stepwise fashion to the C³ position via two sequential 1,4-H shifts, an ion-neutral complex INC₁ of [protonated cyclic N-sulfonyl ketimino esters/indoles] was formed by a charge-directed heterolytic cleavage of the C³ -C¹⁰ bond, while an ion-neutral complex INC₃ of [cyclic N-sulfonyl ketimino esters/protonated indoles] was formed when another labile hydrogen on the N⁸ position successively migrated to the C⁴ position. Direct decomposition of INC₁ and INC₃ resulted in protonated cyclic N-sulfonyl ketimino esters and protonated indoles, respectively, while proton transfer led to protonated indoles and protonated cyclic N-sulfonyl ketimino esters. The HDX reaction with residual water in the HCD cell was also observed. In QTOF-MS/MS, protonated cyclic N-sulfonyl ketimino esters and protonated indoles resulted from direct decomposition of INC₁ and INC₃ , respectively, rather than proton transfer.

CONCLUSIONS

Due to the specific construction of the Q/Orbitrap and QTOF mass spectrometers, different fragmentation mechanisms medicated by ion-neutral complexes of protonated cyclic indolyl α-amino esters were proposed. This study is desirable for qualitative and quantitive investigation of indole derivatives using MS/MS technology.

Metabolic profiling of four South African herbal teas using high resolution liquid chromatography-mass spectrometry and nuclear magnetic resonance

Increased preference to herbal drinks has led to global interest in the use and production of different plant species for the preparation of various drink formulations. Medicinal properties derived from bioactive compounds remain the main driver of choice for herbal teas. This study determined the chemical variation in honeybush, rooibos, special and bush tea, profiled compounds responsible for such differences and compared their peak areas. Nuclear magnetic resonance and high resolution liquid chromatography-mass spectrometry were used to determine compound variation and profiling. Principal component analysis and partial-least square multivariate statistical analysis showed distinct differences (P < 0.05) between the different types of herbal teas. Detected compounds included flavonoids, phenolics, lignans, megastigmane glycoside, most of which possess health benefits. The findings showed that South African herbal teas could play a vital role as health promoting drinks, and that bush tea and special tea are phytochemically comparable with other commercialized herbal teas.

Metabolic Profiling of the Novel Hypoxia-Inducible Factor 2α Inhibitor PT2385 In Vivo and In Vitro

PT2385 is a first-in-class, selective small-molecule inhibitor of hypoxia-inducible factor-2α (HIF-2α) developed for the treatment of advanced clear cell renal cell carcinoma. Preclinical results demonstrated that PT2385 has potent antitumor efficacy in mouse xenograft models of kidney cancer. It also has activity toward metabolic disease in a mouse model. However, no metabolism data are currently publically available. It is of great importance to characterize the metabolism of PT2385 and identify its effect on systemic homeostasis in mice. High-resolution mass spectrometry-based metabolomics was performed to profile the biotransformation of PT2385 and PT2385-induced changes in endogenous metabolites. Liver microsomes and recombinant drug-metabolizing enzymes were used to determine the mechanism of PT2385 metabolism. Real-time polymerase chain reaction analysis was employed to investigate the reason for the PT2385-induced bile acid dysregulation. A total of 12 metabolites of PT2385 was characterized, generated from hydroxylation (M1, M2), dihydroxylation and desaturation (M3, M4), oxidative-defluorination (M7), glucuronidation (M8), N-acetylcysteine conjugation (M9), and secondary methylation (M5, M6) and glucuronidation (M10, M11, and M12). CYP2C19 was the major contributor to the formation of M1, M2, and M7, UGT2B17 to M8, and UGT1A1/3 to M10-M12. The bile acid metabolites taurocholic acid and tauro-β-muricholic acid were elevated in serum and liver of mice after PT2385 treatment. Gene expression analysis further revealed that intestinal HIF-2α inhibition by PT2385 treatment upregulated the hepatic expression of CYP7A1, the rate-limiting enzyme in bile acid synthesis. This study provides metabolic data and an important reference basis for the safety evaluation and rational clinical application of PT2385.

Identification and characterization of vilazodone metabolites in rats and microsomes by ultrahigh-performance liquid chromatography/quadrupole time-of-flight tandem mass spectrometry

RATIONALE

Vilazodone is a selective serotonin reuptake inhibitor (SSRI) used for the treatment of major depressive disorder (MDD). An extensive literature search found few reports on the in vivo and in vitro metabolism of vilazodone. Therefore, we report a comprehensive in vivo and in vitro metabolic identification and structural characterization of vilazodone using ultrahigh-performance liquid chromatography/quadrupole time-of-flight tandem mass spectrometry (UPLC/Q-TOF/MS/MS) and in silico toxicity study of the metabolites.

METHODS

To identify in vivo metabolites of vilazodone, blood, urine and faeces samples were collected at different time intervals starting from 0 h to 48 h after oral administration of vilazodone to Sprague-Dawley rats. The in vitro metabolism study was conducted with human liver microsomes (HLM) and rat liver microsomes (RLM). The samples were prepared using an optimized sample preparation approach involving protein precipitation followed by solid-phase extraction. The metabolites have been identified and characterized by using LC/ESI-MS/MS.

RESULTS

A total of 12 metabolites (M1-M12) were identified in in vivo and in vitro matrices and characterized by LC/ESI-MS/MS. The majority of the metabolites were observed in urine, while a few metabolites were present in faeces and plasma. Two metabolites were observed in the in vitro study. A semi-quantitative study based on percentage counts shows that metabolites M11, M6 and M8 were observed in higher amounts in urine, faeces and plasma, respectively.

CONCLUSIONS

The structures of all the 12 metabolites were elucidated by using LC/ESI-MS/MS. The study suggests that vilazodone was metabolized via hydroxylation, dihydroxylation, glucuronidation, oxidative deamination, dealkylation, dehydrogenation and dioxidation. All the metabolites were screened for toxicity using an in silico tool.

Post-acquisition data mining techniques for LC–MS/MS-acquired data in drug metabolite identification

Metabolite identification is a crucial part of the drug discovery process. LC–MS/MS-based metabolite identification has gained widespread use, but the data acquired by the LC–MS/MS instrument is complex, and thus the interpretation of data becomes troublesome. Fortunately, advancements in data mining techniques have simplified the process of data interpretation with improved mass accuracy and provide a potentially selective, sensitive, accurate and comprehensive way for metabolite identification. In this review, we have discussed the targeted (extracted ion chromatogram, mass defect filter, product ion filter, neutral loss filter and isotope pattern filter) and untargeted (control sample comparison, background subtraction and metabolomic approaches) post-acquisition data mining techniques, which facilitate the drug metabolite identification. We have also discussed the importance of integrated data mining strategy.

Identification of metabolites of palmatine in rats after oral administration using ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry

RATIONALE

Palmatine (PAL), a protopalmatine alkaloid, is an active constituent in a number of medicinal plants. In order to obtain a comprehensive and systematic metabolic profile of PAL, we investigated its metabolites in plasma, liver tissue, bile, urine, and feces samples after intragastrical administration to Sprague-Dawley rats with a dose of 100 mg/kg/day.

METHODS

In this study, a rapid and sensitive method by ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC/QTOF-MS), and Metabolynx™ software with the mass defect filter (MDF) technique was developed for screening and identification of the metabolites. The structural elucidation of the metabolites was performed by comparing their molecular weights and fragment ions with those of the parent drug.

RESULTS

As a result, a total of 58 metabolites were identified in rat biological samples including 46 metabolites in urine, 18 metabolites in plasma, 34 metabolites in bile, 26 metabolites in liver tissue, and 10 metabolites in feces. Among them, six major metabolites were fully confirmed using reference standards and others were identified by retention time, accurate mass and fragment ions.

CONCLUSIONS

These results indicated that phase I reactions (demethylation and hydroxylation) and phase II reaction (glucuronidation and sulfation) were the main metabolic pathways of PAL in vivo. This research enhances our understanding of metabolism of PAL in rats, and provides useful information on the action mechanism of PAL. Copyright © 2017 John Wiley & Sons, Ltd.

Metabolic Profile of Skimmianine in Rats Determined by Ultra-Performance Liquid Chromatography Coupled with Quadrupole Time-of-Flight Tandem Mass Spectrometry

Skimmianine is a furoquinoline alkaloid present mainly in the Rutaceae family. It has been reported to have analgesic, antispastic, sedative, anti-inflammatory, and other pharmacologic activities. Despite its critical pharmacological function, its metabolite profiling is still unclear. In this study, the in vivo metabolite profiling of skimmianine in rats was investigated using ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UPLC/Q-TOF-MS). The metabolites were predicted using MetabolitePilot^TM software. These predicted metabolites were further analyzed by MS² spectra, and compared with the detailed fragmentation pathway of the skimmianine standard and literature data. A total of 16 metabolites were identified for the first time in rat plasma, urine, and feces samples after oral administration of skimmianine. Skimmianine underwent extensive Phase I and Phase II metabolism in rats. The Phase I biotransformations of skimmianine consist of epoxidation of olefin on its furan ring (M1) followed by the hydrolysis of the epoxide ring (M4), hydroxylation (M2, M3), O-demethylation (M5-M7), didemethylation (M14-M16). The Phase II biotransformations include glucuronide conjugation (M8-M10) and sulfate conjugation (M11-M13). The epoxidation of 2,3-olefinic bond followed by the hydrolysis of the epoxide ring and O-demethylation were the major metabolic pathways of skimmianine. The results provide key information for understanding the biotransformation processes of skimmianine and the related furoquinoline alkaloids.

Trends in the application of high-resolution mass spectrometry for human biomonitoring: An analytical primer to studying the environmental chemical space of the human exposome

Global profiling of xenobiotics in human matrices in an untargeted mode is gaining attention for studying the environmental chemical space of the human exposome. Defined as the study of a comprehensive inclusion of environmental influences and associated biological responses, human exposome science is currently evolving out of the metabolomics science. In analogy to the latter, the development and applications of high resolution mass spectrometry (HRMS) has shown potential and promise to greatly expand our ability to capture the broad spectrum of environmental chemicals in exposome studies. HRMS can perform both untargeted and targeted analysis because of its capability of full- and/or tandem-mass spectrum acquisition at high mass accuracy with good sensitivity. The collected data from target, suspect and non-target screening can be used not only for the identification of environmental chemical contaminants in human matrices prospectively but also retrospectively. This review covers recent trends and advances in this field. We focus on advances and applications of HRMS in human biomonitoring studies, and data acquisition and mining. The acquired insights provide stepping stones to improve understanding of the human exposome by applying HRMS, and the challenges and prospects for future research.

Development and validation of an UPLC-Q/TOF-MS assay for the quantitation of neopanaxadiol in beagle dog plasma: Application to a pharmacokinetic study

Neopanaxadiol (NPD), the main panaxadiol constituent of Panax ginseng C. A. Meyer (Araliaceae), has been regarded as the active component for the treatment of Alzheimer's disease. However, few references are available about pharmacokinetic evaluation for NPD. Accordingly, a rapid and sensitive method for quantitative analysis of NPD in beagle dog plasma based on ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry was developed and validated. Analytes were extracted from plasma by liquid-liquid extraction and chromatographic separation was achieved on an Agilent Zorbax Stable Bond C₁₈ column. Detection was performed in the positive ion mode using multiple reaction monitoring of the transitions both at m/z 461.4 → 425.4 for NPD and internal standard of panaxadiol. All validation parameters, such as lower limit of quantitation, linearity, specificity, precision, accuracy, extraction recovery, matrix effect and stability, were within acceptable ranges and the method was appropriate for multitude sample determination. After oral intake, NPD was slowly absorbed and eliminated from circulatory blood system and corresponding plasma exposure was low. Application of this quantitative method will yield the first pharmacokinetic profile after oral administration of NPD to beagle dog. The information obtained here will be useful to understand the pharmacological effects of NPD.

Comprehensive Evaluation of the Metabolism of Genipin-1-β-d-gentiobioside in Vitro and in Vivo by Using HPLC-Q-TOF

To examine the metabolism of genipin-1-β-d-gentiobioside (GG), its distribution and biotransformation in vivo and in vitro were investigated. Urine, plasma, feces, and various organs were collected after oral administration of GG to normal rats and pseudo-germ-free rats to evaluate GG metabolism in vivo. GG was incubated with intestinal flora and primary hepatocytes in vitro to investigate microbial and hepatic metabolism. Using HPLC-Q-TOF-LC/MS, 11 metabolites of GG were absolutely or tentatively identified in terms possible elemental compositions, retention times, and characteristics of fragmentation patterns corresponding to eight biotransformations: deglycosylation, hydroxylation, sulfate conjugation, glucuronidation, hydrogenation, demethylation, glycosylation, and dehydration. Fewer metabolites were detected in pseudo-germ-free rats than in conventional rats. Moreover, geniposide and genipin were generated by the deglycoslation of intestinal bacteria. Geniposidic acid was detected in rat primary-hepatocyte incubation. This study first explores the metabolism of GG in vivo and in vitro. The results can aid the elucidation of PK profiles and clinical usage of gardenia fruit.

Discovery bioanalysis and in vivo pharmacology as an integrated process: a case study in oncology drug discovery

Background: A bioanalytical team dedicated to in vivo pharmacology was set up to accelerate the selection and characterization of compounds to be evaluated in animal models in oncology. Results: A DBS-based serial microsampling procedure was optimized from sample collection to extraction to obtain a generic procedure. UHPLC–high-resolution mass spectrometer configuration allowed for fast quantitative and qualitative analysis. Using an optimized lead compound, we show how bioanalysis supported in vivo pharmacology by generating blood and tumor exposure, drug monitoring and PK/PD data. Conclusion: This process provided unique opportunities for the characterization of drug properties, selection and assessment of compounds in animal models and to support and expedite proof-of-concept studies in oncology.