A novel LC-MS/MS method for complete composition analysis of polysaccharides by aldononitrile acetate and multiple reaction monitoring

New analytical methods focusing on polar metabolite analysis in mass spectrometry and NMR-based metabolomics

Following in the footsteps of genomics and proteomics, metabolomics has revolutionised the way we investigate and understand biological systems. Rapid development in the last 25 years has been driven largely by technical innovations in mass spectrometry and nuclear magnetic resonance spectroscopy. However, despite the modest size of metabolomes relative to proteomes and genomes, methodological capabilities for robust, comprehensive metabolite analysis remain a major challenge. Therefore, development of new methods and techniques remains vital for progress in the field. Here, we review developments in LC-MS, GC-MS and NMR methods in the last few years that have enhanced quantitative and comprehensive metabolome coverage, highlighting the techniques involved, their technical capabilities, relative performance, and potential impact.

Recent trends in extraction, purification, structural characterization, and biological activities evaluation of Perilla frutescens (L.) Britton polysaccharide

Perilla frutescens (L.) Britton is an annual herb plant of the Perilla genus in the Labiatae family, which is commonly utilized as an edible and medicinal resource. Polysaccharides are among the major components and essential bioactive compounds of P. frutescens, which exhibit a multitude of biological activities, including antioxidant, antitumor, anti-fatigue, immunoregulation, hepatoprotective, anti-inflammatory, and lipid-lowering effects. As a natural carbohydrate, P. frutescens polysaccharide has the potential to be utilized in the development of drugs and functional materials. In this paper, we provide an overview of progress made on the extraction, purification, structural characterization, and bioactivity of polysaccharides from different parts of P. frutescens. The challenges and opportunities for research are discussed, along with the potential development prospects and future areas of focus in the study of P. frutescens polysaccharides.

Recent advances in Platycodon grandiflorum polysaccharides: Preparation techniques, structural features, and bioactivities

Platycodon grandiflorum, a globally recognized medicinal and edible plant, possesses significant nutritional value and pharmacological value. In traditional Chinese medicine, it has the effects of tonifying the spleen and replenishing the Qi, moistening the lung and relieving the cough, clearing the heat and detoxifying, and relieving the pain. Accumulating evidence has revealed that the polysaccharides from P. grandiflorum (PGPs) are one of the major and representative biologically active macromolecules and have diverse biological activities, such as immunomodulatory activity, anti-inflammatory activity, anti-tumor activity, regulation of the gut microbiota, anti-oxidant activity, anti-apoptosis activity, anti-angiogenesis activity, hypoglycemic activity, anti-microbial activity, and so on. Although the polysaccharides extracted from P. grandiflorum have been extensively studied for the extraction and purification methods, structural characteristics, and pharmacological activities, the knowledge of their structures and bioactivity relationship, toxicologic effects, and pharmacokinetic profile is limited. The main purpose of the present review is to provide comprehensively and systematically reorganized information on extraction and purification, structure characterizations, and biological functions as well as toxicities of PGPs to support their therapeutic potentials and sanitarian functions. New valuable insights for future research regarding PGPs were also proposed in the fields of therapeutic agents and functional foods.

Chemical Characterization of the Precipitate Found in and Its Effect on Drug Release of the Scutellaria baicalensis-Coptis chinensis Extract

Precipitate generation is a challenging issue during the production of herbal decoction as it affects the stability and bioavailability of active compounds. Here we explored the composition of the natural precipitate formed from and its effect on drug release of Scutellaria baicalensis-Coptis chinensis paired extract (SCPE). Furthermore, the surface morphology of the SCPE precipitate was also investigated. Ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) was used to chemical component analysis and field emission scanning electron microscope (FE-SEM) was performed to particle observation. Baicalin (BA), berberine (BBR) and starch-arginine-rich polymers were abundant in the SCPE precipitate. FE-SEM micrographs showed spheroidal shaped particles in the SCPE supernatant, while spherical and porous tissue-shaped particles in the SCPE precipitate. In vitro drug release of baicalin and berberine contained in the precipitate may increase as the polymer is removed. The presence of polymer-related interactions were confirmed by the greater increase in solubility of baicalin upon addition of arginine and polymer. This was also supported by the solubility decrease of the BA-BBR complex in polymer solution and the gelation of the BA-BBR complex in arginine solution. Our results provide a scientific basis for elucidating the pharmaceutical properties of the decoction of S. baicalensis-C. chinensis-based herbal medicine.

A Systematic Investigation of Complement and Coagulation-Related Protein in Autism Spectrum Disorder Using Multiple Reaction Monitoring Technology

Autism spectrum disorder (ASD) is one of the common neurodevelopmental disorders in children. Its etiology and pathogenesis are poorly understood. Previous studies have suggested potential changes in the complement and coagulation pathways in individuals with ASD. In this study, using multiple reactions monitoring proteomic technology, 16 of the 33 proteins involved in this pathway were identified as differentially-expressed proteins in plasma between children with ASD and controls. Among them, CFHR3, C4BPB, C4BPA, CFH, C9, SERPIND1, C8A, F9, and F11 were found to be altered in the plasma of children with ASD for the first time. SERPIND1 expression was positively correlated with the CARS score. Using the machine learning method, we obtained a panel composed of 12 differentially-expressed proteins with diagnostic potential for ASD. We also reviewed the proteins changed in this pathway in the brain and blood of patients with ASD. The complement and coagulation pathways may be activated in the peripheral blood of children with ASD and play a key role in the pathogenesis of ASD.

Precolumn derivatization LC-MS/MS method to simultaneous quantitation of 10 monosaccharides in rat plasma

Monosaccharides are essential for maintaining the normal physiological functions of living organisms. Under disease states, metabolic disorders in vivo will inevitably affect the levels of monosaccharides, which brings the possibility of monosaccharides as a biomarker of some diseases. In this study, a method was developed and validated for simultaneously determining 10 monosaccharides (glucose, galactose, mannose, rhamnose, fucose, xylose, iduronic acid, glucuronic acid, N-acetylgalactosamine and N-acetylglucosamine) in SD rat plasma using liquid chromatography-tandem mass spectrometry. The method employed 1-phenyl-3-methyl-5-pyrazolone (PMP) as a derivatization reagent, considerably improved the chromatographic retention and ionization efficiency of monosaccharides. After protein precipitation of plasma samples, monosaccharides and isotope internal standards were derivatized and liquid-liquid extraction was performed to remove excess PMP. To achieve the baseline separation of several isomers, the resulting derivatives were chromatographed on a Bridged ethyl hybrid (BEH) Phenyl column using gradient elution with a total run time of 8 min. The method was linear within the range of 0.0100-5.00 μg/mL for rhamnose, 0.0500-25.0 μg/mL for fucose, xylose, iduronic acid, glucuronic acid, N-acetylgalactosamine and N-acetylglucosamine, 1.00-500 μg/mL for galactose, 10.0-5000 μg/mL for mannose, and 50.0-25,000 μg/mL for glucose. And the accuracy and precision verification of surrogate matrix samples and plasma samples met the required criteria. The method has been used successfully to study the effect of hepatic insufficiency on monosaccharide levels in rats. It was found that the concentration of glucuronic acid in SD rat plasma was abnormally increased in rats with liver injury.

Structure of an unprecedent glucuronoxylogalactoglucomannan from fruit bodies of Auricularia auricula-judae (black woody ear)

An unprecedent glucuronoxylogalactoglucomannan (GXG'G″M), ME-2 (M_w, 2.60 × 10⁵ g/mol; O-acetyl % = 16.7 %), was isolated and purified from water extracts of Auricularia auricula-judae (black woody ear). Firstly, due to much higher O-acetyl contents, we prepared its fully deacetylated products (dME-2; M_w, 2.13 × 10⁵ g/mol) for convenient structure survey. The repeating structure-unit of dME-2 was readily proposed based on M_w determination, monosaccharide compositions, methylation analysis, free-radical degradation and 1/2D NMR spectroscopy. The dME-2 was identified as a highly branched polysaccharide with an average of 10 branches per 10 sugar backbone units. The backbone was only repeating →3)-α-Manp-(1→ residues, substituted at the C-2, C-6 and C-2,6 positions. The side chains included β-GlcAp-(1→, β-Xylp-(1→, α-Manp-(1→, α-Galp-(1→ and β-Glcp-(1→. Secondly, the complex substituted positions of O-acetyl groups in ME-2 were determined to be at C-2, C-4, C-6 and C-4,6 in the backbone and at C-2 and C-2,3 in some side chains. Finally, the anti-inflammatory activity of ME-2 was preliminarily explored on LPS-stimulated THP-1 cells. The above date not only provided the first example for structural studies of GXG'G″M type polysaccharides, but also facilitated development and application of black woody ear polysaccharides as medicinal agents or functional dietary supplements.

Extraction, purification, structural characterization and biological activity of polysaccharides from Fritillaria: A review

Fritillaria is a traditional Chinese medicine(TCM) with a history of thousands of years. Fritillaria always contain saponins, alkaloids, amino acids, flavones, and polysaccharides. Among them, Fritillaria polysaccharide has a variety of biological activities. Its anti-inflammatory and antiaging activities are new study hotspots. The extraction, purification, quantitative determination, monosaccharide composition, and biological activity of Fritillaria polysaccharides have been examined for several years in an attempt to identify the active components and understand the pharmacological process. In this review, ample original publications related to the distribution, extraction, purification, quantitative determination, monosaccharide composition and biological activities of Fritillaria until 2023 were searched and collected by using various literature databases. Databases included the China National Knowledge Infrastructure, VIP database, Wan Fang database, PubMed, Elsevier, Springer, Science Direct, Google Scholar and Web of Science database, as well as the classic Chinese medical books and PhD and MSc theses. The properties and outcomes of various extractions, purifications, quantitative determination methods, monosaccharide compositions, and biological activities of Fritillaria polysaccharides are discussed here. Additionally, we summarize the research potential of Fritillaria polysaccharide and identify promising research direction candidates.

An alternative strategy based on ultra-high-performance supercritical fluid chromatography for full monosaccharide compositional analysis of polysaccharides in Schisandra chinensis fruits

Due to green and environment-friendly characteristics, ultra-high-performance supercritical fluid chromatography has been widely used in analytical fields in recent years, but until now few reports are available for monosaccharide compositional analysis of macromolecule polysaccharides. In this study, an ultra-high-performance supercritical fluid chromatography technology with an unusual binary modifier is used to determine the monosaccharide compositions of natural polysaccharides. Each carbohydrate herein is simultaneously labeled as 1-pheny-3-methyl-5-pyrazolone and acetyl-derivative via pre-column derivatizations aiming to increase UV absorption sensitivity and decrease water solubility. Ten common monosaccharides are fully separated and detected on ultra-high-performance supercritical fluid chromatography combined with a photo-diode array detector by systematic optimization of multiple relevant parameters, for example, column stationary phases, organic modifiers, additives, flow rates, and so on. Compared with carbon dioxide as a mobile phase, the addition of a binary modifier increases the resolution of analytes. Additionally, this method has the advantages of small consumption of organic solvent, safety, and being environmental-friendly. It has been successfully applied for full monosaccharide compositional analysis of heteropolysaccharides from Schisandra chinensis fruits. To sum up, a new alternative approach is provided for monosaccharide compositional analysis of natural polysaccharides.

Isolation, structures, bioactivities, application and future prospective for polysaccharides from Tremella aurantialba: A review

Since ancient times, Tremella aurantialba has been proposed to have medicinal and food benefits. Modern phytochemistry and pharmacological studies have demonstrated that polysaccharides, the main components from T. aurantialba appear to be an all-round talent resisting a variety of chronic inflammatory diseases and protecting against different types of tumors, diabetes and cardiovascular diseases. These health and pharmacological benefits have gained much attention from scholars around the world. Further, more and more methods for polysaccharides extraction, purification, structure identification have been proposed. Significantly, the bioactivity of fungus polysaccharides is affected by many factors such as extraction and purification conditions and chemical structure. This paper provides an overview of recent advances in the isolation, structural features and biological effects of polysaccharides derived from T. aurantialba, covers recent advances in the field and outlines future research and applications of these polysaccharides.

A nondestructive solution to quantify monosaccharides by ATR-FTIR and multivariate regressions: A case study of Atractylodes polysaccharides

The quality evaluation of nature polysaccharides is a tough nut to crack because of its high M_w distributions and larger polarity property. It is well-known that infrared spectroscopy and multiple regression modeling have been used for quantitative examinations in multiple fields, but it has not been applied to the compositional analysis of polysaccharides. In this study, attenuated total reflectance-fourier transform infrared spectroscopy is used to simultaneously quantify aldoses, ketose and uronic acids in Atractylodes polysaccharides by a combination of multivariate regressions. After experience of different data processing pretreatments, the resulting spectrum contains maximum amount of information of monosaccharide contents in Atractylodes polysaccharides. In this case, different smoothing points, derivatives, SNV and MSC are used in the pre-modeling spectrum processing and VIP screening is used to reduce the number of variables to simplify the calculation of the model. All the most optimal prediction models have both good prediction ability (R² ≥ 0.9 and RPD > 3) and no over fitting (RMSEP/RMSEC < 3). This strategy has opened a new possibility for the nondestructive determination of complex monosaccharide compositions of natural polysaccharides in a short detection time, low equipment requirement and high experimental safety.

Integrated Metabolome and Lipidome Strategy to Reveal the Action Pattern of Paclobutrazol, a Plant Growth Retardant, in Varying the Chemical Constituents of Platycodon Root

Platycodon root, a medicinal food homology species which has been used in Asian countries for hundreds of years, is now widely cultivated in China. Treatment with paclobutrazol, a typical plant growth retardant, has raised uncertainties regarding the quality of Platycodon root, which have been rarely investigated. In the present study, metabolomic and lipidomic differences were revealed by ultra-high performance liquid chromatography coupled to ion mobility-quadrupole time of flight mass spectrometry (UPLC-IM-QTOF-MS). A significant decrease of platycodigenin-type saponins was observed in the paclobutrazol-treated sample. Carrying out a comprehensive quantitative analysis, the contents of total saponins and saccharides were determined to illustrate the mode of action of paclobutrazol on Platycodon root. This study demonstrated an exemplary research model in explaining how the exogenous matter influences the chemical properties of medicinal plants, and therefore might provide insights into the reasonable application of plant growth regulators.

Effects of monosaccharide composition on quantitative analysis of total sugar content by phenol-sulfuric acid method

Phenol-sulfuric acid method is one of the most common methods applied to the analysis of total sugar content during polysaccharides study. However, it was found that the results obtained from the phenol-sulfuric acid method was generally lower than the real total sugar content, especially when acidic monosaccharides were contained in the polysaccharides samples. Therefore, the present study focused to unveil the proposed problem. Based on the optimization of colorimetric conditions, such as optimal wave length of absorption, linearity range, color reaction time and temperature, it indicated that the phenol-sulfuric acid method was a convenient and accurate way for the total sugar content analysis. In addition, the color-rendering capabilities of 10 common monosaccharides were systematically analyzed to obtain a relative correction factor for each monosaccharide relative to glucose, which was proved to be the main reason for the deviation in the detection of total sugar content. Moreover, the key points during the application of phenol-sulfuric acid method were suggested. This study provides a scientific theoretical basis and a reliable experimental research method for the accurate determination of total sugar content by the phenol-sulfuric acid method, and which will also promote the application of this convenient method in the polysaccharides study.

Nanopore Identification of Alditol Epimers and Their Application in Rapid Analysis of Alditol-Containing Drinks and Healthcare Products

Alditols, which have a sweet taste but produce much lower calories than natural sugars, are widely used as artificial sweeteners. Alditols are the reduced forms of monosaccharide aldoses, and different alditols are diastereomers or epimers of each other and direct and rapid identification by conventional methods is difficult. Nanopores, which are emerging single-molecule sensors with exceptional resolution when engineered appropriately, are useful for the recognition of diastereomers and epimers. In this work, direct distinguishing of alditols corresponding to all 15 monosaccharide aldoses was achieved by a boronic acid-appended hetero-octameric Mycobacterium smegmatis porin A (MspA) nanopore (MspA-PBA). Thirteen alditols including glycerol, erythritol, threitol, adonitol, arabitol, xylitol, mannitol, sorbitol, allitol, dulcitol, iditol, talitol, and gulitol (l-sorbitol) could be fully distinguished, and their sensing features constitute a complete nanopore alditol database. To automate event classification, a custom machine-learning algorithm was developed and delivered a 99.9% validation accuracy. This strategy was also used to identify alditol components in commercially available "zero-sugar" drinks and healthcare products, suggesting their use in rapid and sensitive quality control for the food and medical industry.

Analysis of the chemical composition of natural carbohydrates - An overview of methods

Natural carbohydrates are gaining importance over a wide spectrum of human activity due to their versatile functionalities. The properties of carbohydrates are currently used in many branches of industry and new possibilities of their utilization, like in medicine or materials science, are demonstrated systematically. The attractive properties of carbohydrates result from their chemical structure and ability to form macromolecules and derivatives. Each application of carbohydrate requires a knowledge of their chemical composition, which due to the number and differentiation of monosaccharides and their spatial forms is often challenging. This review presents an overview on sample preparation and the methods used for the determination of the fine chemical structure of natural carbohydrates. Most popular and reliable colorimetric, chromatographic and spectroscopic methods are presented with an emphasis on their pros and cons.

Structural Elucidation and Activities of Cordyceps militaris-Derived Polysaccharides: A Review

Cordyceps militaris is a parasitic edible fungus and has been used as tonics for centuries. Polysaccharides are a major water-soluble component of C. militaris. Recently, C. militaris-derived polysaccharides have been given much attention due to their various actions including antioxidant, anti-inflammatory, anti-tumor, anti-hyperlipidemic, anti-diabetic, anti-atherosclerotic, and immunomodulatory effects. These bioactivities are determined by the various structural characteristics of polysaccharides including monosaccharide composition, molecular weight, and glycosidic linkage. The widespread use of advanced analytical analysis tools has greatly improved the elucidation of the structural characteristics of C. militaris-derived polysaccharides. However, the methods for polysaccharide structural characterization and the latest findings related to C. militaris-derived polysaccharides, especially the potential structure-activity relationship, have not been well-summarized in recent reviews of the literature. This review will discuss the methods used in the elucidation of the structure of polysaccharides and structural characteristics as well as the signaling pathways modulated by C. militaris-derived polysaccharides. This article provides information useful for the development of C. militaris-derived polysaccharides as well as for investigating other medicinal polysaccharides.