Exploring the Application of the DSA-TOF, a Direct, High-resolution Time-of-Flight Mass Spectrometry Technique for the Screening of Potential Adulterated and Contaminated Herbal Medicines

Scaptotrigona mexicana Propolis from Totonacapan Region: Chemical Composition, Antioxidant and Antibacterial Activities

The propolis produced by stingless bees is a complex mixture of natural sticky components mixed with soil or clay. Global research on propolis has focused on studying the biological and pharmacological properties and chemical composition of stingless bee propolis from Brazil, Indonesia, and other regions. However, studies of stingless bee propolis produced in Mexico are scarce. This study aimed to determine the chemical composition of the geopropolis of Scaptotrigona mexicana collected in the Totonacapan region and to evaluate its antioxidant and antibacterial activities. The phenolic contents of the ethanolic extract of the collected propolis ranged from 2.45 ± 0.03 mg GAE/g to 3.48 ± 0.56 mg GAE/g of dry extract. The total flavonoid content ranged from 0.69 ± 0.03 mg QE/g to 0.84 ± 0.009 mg QE/g of dry extract. The antioxidant activity of the ethanolic extracts was assessed via DPPH, ABTS, and FRAP assays. The minimum inhibitory concentration values exhibited by the ethanolic extract (>512 g/mL) for Gram-negative bacteria (Pseudomonas aerugunosa and Phorphyromonas gingivalis) were higher than those of Gram-positive bacteria. The stingless bee propolis extract showed the highest antibacterial activity against Streptococcus mutans (256 g/mL). Five known compounds, taraxeryl acetate (1), lupeol (3), cicloart-23-en-3β,25-diol (5), mangiferoic acid (6), and 5-(11'Z-heptadecenyl)-resorcinol (7), and two irresoluble mixtures of 3-O-acetyl-α-(2a) and 3-O-acetyl-β-amyrins (2b), and α- (4a) and -amyrins (4b), were identified by nuclear magnetic resonance spectroscopy and mass spectrometry. Additionally, 39 volatile compounds were identified via headspace-solid phase microextraction using the hyphenated gas chromatography coupled to mass spectrometry time-of-flight. The main volatile compounds detected include trans-α-bergamotene (8.15%), hexanal (7.17%), 2-heptanone (7.60%), and α-copaene (7.09%).

Swab-in-Capillary Electrospray Ionization and a Miniature Mass Spectrometer for In Situ Drug Analysis

In situ analysis of drugs has been in increasing demand in many fields. As an updated version of capillary-in-capillary electrospray ionization (CC-ESI) developed previously, a disposable swab-in-capillary electrospray ionization (SC-ESI) source was designed in this study. With a micro medical swab for sampling and an integrated filter membrane for online filtration, SC-ESI was able to directly sample and MS analyze complex samples without the need for pretreatment. Coupled with a miniature mass spectrometer, SC-ESI was applied for direct analysis of effective ingredients in therapeutic drugs (in tablet, capsule, and liquid droplet) and drugs in saliva and quantitation of therapeutic drugs in blood. The limits of detection in absolute amounts were obtained as 1 ng for fentanyl and 0.5 ng for cocaine in saliva. Combining with an internal standard method, SC-ESI acquired linear quantitation ranges of 100-5000 ng/mL for imatinib in whole blood and 100-2000 ng/mL for clozapine in serum with high accuracies and precisions. The entire analysis process, from sampling to data acquisition, can be completed in less than 2 min. As demonstrated as a cheap, portable, and sampling-effective ionization source, SC-ESI has shown great potential for in situ drug analysis, especially in border drug screening and clinical therapeutic drug monitoring.

Small molecule metabolites: discovery of biomarkers and therapeutic targets

Metabolic abnormalities lead to the dysfunction of metabolic pathways and metabolite accumulation or deficiency which is well-recognized hallmarks of diseases. Metabolite signatures that have close proximity to subject's phenotypic informative dimension, are useful for predicting diagnosis and prognosis of diseases as well as monitoring treatments. The lack of early biomarkers could lead to poor diagnosis and serious outcomes. Therefore, noninvasive diagnosis and monitoring methods with high specificity and selectivity are desperately needed. Small molecule metabolites-based metabolomics has become a specialized tool for metabolic biomarker and pathway analysis, for revealing possible mechanisms of human various diseases and deciphering therapeutic potentials. It could help identify functional biomarkers related to phenotypic variation and delineate biochemical pathways changes as early indicators of pathological dysfunction and damage prior to disease development. Recently, scientists have established a large number of metabolic profiles to reveal the underlying mechanisms and metabolic networks for therapeutic target exploration in biomedicine. This review summarized the metabolic analysis on the potential value of small-molecule candidate metabolites as biomarkers with clinical events, which may lead to better diagnosis, prognosis, drug screening and treatment. We also discuss challenges that need to be addressed to fuel the next wave of breakthroughs.

Plasma-based ambient mass spectrometry: Recent progress and applications

Ambient mass spectrometry (AMS) has grown as a group of advanced analytical techniques that allow for the direct sampling and ionization of the analytes in different statuses from their native environment without or with minimum sample pretreatments. As a significant category of AMS, plasma-based AMS has gained a lot of attention due to its features that allow rapid, real-time, high-throughput, in vivo, and in situ analysis in various fields, including bioanalysis, pharmaceuticals, forensics, food safety, and mass spectrometry imaging. Tens of new methods have been developed since the introduction of the first plasma-based AMS technique direct analysis in real-time. This review first provides a comprehensive overview of the established plasma-based AMS techniques from their ion source configurations, mechanisms, and developments. Then, the progress of the representative applications in various scientific fields in the past 4 years (January 2017 to January 2021) has been summarized. Finally, we discuss the current challenges and propose the future directions of plasma-based AMS from our perspective.

The Importance of Reference Materials and Method Validation for Advancing Research on the Health Effects of Dietary Supplements and Other Natural Products

Insufficient assessment of the identity and chemical composition of complex natural products, including botanicals, herbal remedies, and dietary supplements, hinders reproducible research and limits understanding mechanism(s) of action and health outcomes, which in turn impede improvements in clinical practice and advances in public health. This review describes available analytical resources and good methodological practices that support natural product characterization and strengthen the knowledge gained for designing and interpreting safety and efficacy investigations. The practice of validating analytical methods demonstrates that measurements of constituents of interest are reproducible and appropriate for the sample (e.g., plant material, phytochemical extract, and biological specimen). In particular, the utilization of matrix-based reference materials enables researchers to assess the accuracy, precision, and sensitivity of analytical measurements of natural product constituents, including dietary ingredients and their metabolites. Select case studies are presented where the careful application of these resources and practices has enhanced experimental rigor and benefited research on dietary supplement health effects.

Promoting Human Nutrition and Health through Plant Metabolomics: Current Status and Challenges

Simple Summary

This review summarizes the status, applications, and challenges of plant metabolomics in the context of crop breeding, food quality and safety, and human nutrition and health. It also highlights the importance of plant metabolomics in elucidating biochemical and genetic bases of traits associated with nutritive and healthy beneficial foods and other plant products to secure food supply, to ensure food quality, to protect humans from malnutrition and other diseases. Meanwhile, this review calls for comprehensive collaborations to accelerate relevant researches and applications in the context of human nutrition and health.

Abstract

Plant metabolomics plays important roles in both basic and applied studies regarding all aspects of plant development and stress responses. With the improvement of living standards, people need high quality and safe food supplies. Thus, understanding the pathways involved in the biosynthesis of nutritionally and healthily associated metabolites in plants and the responses to plant-derived biohazards in humans is of equal importance to meet people’s needs. For each, metabolomics has a vital role to play, which is discussed in detail in this review. In addition, the core elements of plant metabolomics are highlighted, researches on metabolomics-based crop improvement for nutrition and safety are summarized, metabolomics studies on plant natural products including traditional Chinese medicine (TCM) for health promotion are briefly presented. Challenges are discussed and future perspectives of metabolomics as one of the most important tools to promote human nutrition and health are proposed.

The current role of mass spectrometry in forensics and future prospects

Mass spectrometry (MS) techniques are highly prevalent in crime laboratories, particularly those coupled to chromatographic separations like gas chromatography (GC) and liquid chromatography (LC). These methods are considered "gold standard" analytical techniques for forensic analysis and have been extensively validated for producing prosecutorial evidentiary data. However, factors such as growing evidence backlogs and problematic evidence types (e.g., novel psychoactive substance (NPS) classes) have exposed limitations of these stalwart techniques. This critical review serves to delineate the current role of MS methods across the broad sub-disciplines of forensic science, providing insight on how governmental steering committees guide their implementation. Novel, developing techniques that seek to broaden applicability and enhance performance will also be highlighted, from unique modifications to traditional hyphenated MS methods to the newer "ambient" MS techniques that show promise for forensic analysis, but need further validation before incorporation into routine forensic workflows. This review also expounds on how recent improvements to MS instrumental design, scan modes, and data processing could cause a paradigm shift in how the future forensic practitioner collects and processes target evidence.