Optimizing microwave-assisted hydrolysis conditions for monosaccharide composition analyses of different polysaccharides

Characterization, Optimization, and Scaling-up of Submerged Inonotus hispidus Mycelial Fermentation for Enhanced Biomass and Polysaccharide Production

This study was to establish an efficient strategy based on inoculum-morphology control for the submerged mycelial fermentation of an edible and medicinal fungus, Inonotus hispidus. Two major morphological forms of the mycelial inoculum were compared, dispersed mycelial fragments versus aggregated mycelial clumps. The dispersed one was more favorable for the fermentation, starting with a shorter lag period and attaining a higher biomass yield and more uniform mycelium pellets in shake flasks. The mycelial pellets taken from the shake flask culture on day 6 were fragmented at 26,000 rpm in a homogenizer, and a shear time of 3 min provided the optimal inoculum. The inoculum and culture conditions were further verified in 5-L stirred tank fermenters and then the fermentation was scaled-up in a 100-L stirred tank. With the optimized inoculum and process conditions plus a fed-batch operation, much higher productivities, including 22.23 g/L biomass, 3.31 g/L EPS, and 5.21 g/L IPS, were achieved in the 100-L fermenter than in the flask culture. A composition analysis showed that the I. hispidus mycelium produced by the fermentation was rich in protein, dietary fiber, and polysaccharides which may be beneficial to health. Overall, the results have shown that the inoculum characteristics including age, morphology, and state of aggregation have significant impact on the productivity of mycelial biomass and polysaccharides in a submerged mycelial fermentation of the I. hispidus fungus.

Research progress in methods of acquisition, structure elucidation, and quality control of Chinese herbal polysaccharides

The therapeutic efficacy of traditional Chinese medicine has been widely acknowledged due to its extensive history of clinical effectiveness. However, the precise active components underlying each prescription remain incompletely understood. Polysaccharides, as a major constituent of water decoctions-the most common preparation method for Chinese medicinals-may provide a crucial avenue for deepening our understanding of the efficacy principles of Chinese medicine and establishing a framework for its modern development. The structural complexity and diversity of Chinese herbal polysaccharides present significant challenges in their separation and analysis compared to small molecules. This paper aims to explore the potential of Chinese herbal polysaccharides efficiently by briefly summarizing recent advancements in polysaccharide chemical research, focusing on methods of acquisition, structure elucidation, and quality control.

Isolation, structures, bioactivities, and applications of the polysaccharides from Boletus spp.: A review

Boletus spp., the edible mushrooms distributed in Europe, Asia, and North America, have been widely used as food and medicinal ingredients worldwide. Bioactive polysaccharides are highly abundant in Boletus spp., as demonstrated by modern phytochemical studies. The isolation, chemical properties, and bioactivities of polysaccharides from Boletus spp. have long been attracted by academics worldwide. However, there is still a lack of systematic tracking of research progress on Boletus polysaccharides (BPs), which is essential for researchers to understand their potential and gain a deeper insight into their functional mechanisms. In this review, we summarized the recent development of BPs, including the extraction and purification methods, physiochemical and structural features, bioactivities and functional mechanisms, the structure-activity relationship, and the potential applications. This review aims to provide researchers with a comprehensive understanding of the current progress and potential of BPs to assist their further investigations.

Structural characterization, antioxidant and immunomodulatory activities of a polysaccharide from a traditional Chinese rice wine, Guangdong Hakka Huangjiu

Hakka Huangjiu, a traditional Chinese rice wine, boasts a rich history and is known for its immunomodulatory, antibacterial, anti-aging and anti-fatigue effects. However, there is limited research on the primary active components and molecular mechanism of the bioactivity of Hakka Huangjiu. To address this gap, this study assessed the structural characteristics, antioxidant, and immunomodulatory activities of the polysaccharide-1 of Guangdong Hakka Huangjiu (HP1). Structural analysis revealed that HP1 had a low molecular weight polysaccharide of 5550 Da, primarily consisting of glucose (93.2 %), with smaller amounts of xylose, mannuronic acid and galactose. Methylation and NMR analysis suggested that the main glycosidic linkages present in HP1 are α-D-Glcp-(1→, →4)-α-D-Glcp-(1 → and →6) -α-D-Glcp-(1→. Furthermore, HP1 exhibited dose-dependent DPPH·, ABTS+ and OH· scavenging activity. HP1 exhibited significant protection of HepG2 cells from H2O2 damage. Additionally, HP1 induced the release of NO, TNF-α, IL-6 and iNOS in RAW264.7 cells. HP1 treatment significantly increased mRNA expression of TNF-α, IL-6, iNOS, COX-2, IL-1β and TGF-β1. These results suggested that polysaccharides HP1 may have potential as a novel natural antioxidant and immunomodulatory product for use in nutraceuticals and functional foods.

An optimize adaptable method for determining the monosaccharide composition of pectic polysaccharides

Pectic polysaccharides are considered the highly complex natural plant polysaccharides which plays a vital role in plant tissue structure and human health. Detailed characterization of the monosaccharide composition can provide insights into the pectic polysaccharide structure. Nevertheless, when analyzing the monosaccharides of pectic polysaccharide, it is crucial to address the issue of incomplete hydrolysis that can occur due to the formation of acid-induced precipitates. Based on above, the main purpose of this article is to provide an optimized method for monosaccharide analysis of pectic polysaccharides through acid hydrolysis optimization using high-performance anion exchange chromatography (HPAEC) The results indicate that reducing the sample concentration to 0.5 mg/mL effectively reduces the acid gelling phenomenon and promotes the complete hydrolysis of pectin polysaccharides. The optimized parameters for acid hydrolysis involve 110 °C for 6 h in 2 M TFA. Furthermore, the consistency of this method is assessed, along with its ability to analyze pectin polysaccharides from various fruits. This hydrolysis approach holds promise for enabling accurate quantification of monosaccharide composition in pectic polysaccharides.

Novel quinazolin-6-yl Isoindolinone: Altering polysaccharide chemstructure for antibacterial efficacy against Staphylococcus aureus

The ongoing development of novel strategies to combat Staphylococcus aureus and eliminate its biofilm formation has gained significant attention for human health. Antibiotic-resistant S. aureus necessitates the development of novel antibacterial agents with new mechanism of action. This study introduced a promising recently synthesized quinazolin-6-yl isoindolinone (IQE-X1), which exhibited potent antibacterial and antibiofilm efficacy with average median inhibitory concentration (IC50) of 3.37 μg mL-1 and minimal inhibitory concentration (MIC) of 12.5 μg mL-1, coupled with its ability to reduce cell surface hydrophobicity. IQE-X1 dose-dependently decreased extracellular polysaccharides (EPS) and its component monosaccharides, including rhamnose, arabinose, glucosamine, galactose, glucose, xylose, mannose, and ribose, accompanied by an increase in capsular polysaccharides (CP) and its individual monosaccharides, especially glucosamine. IQE-X1 demonstrated specificity in modulating the structural profiles of EPS and CP by altering the compositional ratios of their component monosaccharides. The potential mechanism of polysaccharide modulation was preliminarily elucidated through the response of β-N-acetylaminoglucosidase to IQE-X1 and their direct binding interaction. These findings provide new insights into the potential manipulation of the chemstructure of these biologically important macromolecules, EPS and CP, and highlight the antibacterial potential of IQE-X1 as a polysaccharide modulator for the development of more effective polysaccharide-targeted strategies against S. aureus.

The Pre- and Post-Column Derivatization on Monosaccharide Composition Analysis, a Review

Polysaccharides, as common metabolic products in organisms, play a crucial role in the growth and development of living organisms. For humans, polysaccharides represent a class of compounds with diverse applications, particularly in the medical field. Therefore, the exploration of the monosaccharide composition and structural characteristics of polysaccharides holds significant importance in understanding their biological functions. This review provides a comprehensive overview of extraction methods and hydrolysis strategies for polysaccharides. It systematically analyzes strategies and technologies for determining polysaccharide composition and discusses common derivatization reagents employed in further polysaccharide studies. Derivatization is considered a fundamental strategy for determining monosaccharides, as it not only enhances the detectability of analytes but also increases detection sensitivity, especially in liquid chromatography (LC), capillary electrophoresis (CE), and gas chromatography (GC) techniques. The review meticulously examines pre-column and post-column derivatization techniques for monosaccharide analysis, categorizing them based on diverse detection methodologies. It delves into the principles and distinctive features of various derivatization reagents, offering a comparative analysis of their strengths and limitations. Ultimately, the aim is to provide guidance for selecting the most suitable derivatization approach, taking into account the structural nuances, biological functions, and reaction dynamics of polysaccharides.

Research of saccharides and related biocomplexes: A review with recent techniques and applications

Saccharides and biocompounds as saccharide (sugar) complexes have various roles and biological functions in living organisms due to modifications via nucleophilic substitution, polymerization, and complex formation reactions. Mostly, mono-, di-, oligo-, and polysaccharides are stabilized to inactive glycosides, which are formed in metabolic pathways. Natural saccharides are important in food and environmental monitoring. Glycosides with various functionalities are significant in clinical and medical research. Saccharides are often studied with the chromatographic methods of hydrophilic interaction liquid chromatography and anion exchange chromatograpy, but also with capillary electrophoresis and mass spectrometry with their on-line coupling systems. Sample preparation is important in the identification of saccharide compounds. The cases discussed here focus on bioscience, clinical, and food applications.

Extraction, purification, structural characteristics, biological activities, and applications of polysaccharides from the genus Lilium: A review

The genus Lilium (Lilium) has been widely used in East Asia for over 2000 years due to its rich nutritional and medicinal value, serving as both food and medicinal ingredient. Polysaccharides, as one of the most important bioactive components in Lilium, offer various health benefits. Recently, polysaccharides from Lilium plants have garnered significant attention from researchers due to their diverse biological properties including immunomodulatory, anti-oxidant, anti-diabetic, anti-tumor, anti-bacterial, anti-aging and anti-radiation effects. However, the limited comprehensive understanding of polysaccharides from Lilium plants has hindered their development and utilization. This review focuses on the extraction, purification, structural characteristics, biological activities, structure-activity relationships, applications, and relevant bibliometrics of polysaccharides from Lilium plants. Additionally, it delves into the potential development and future research directions. The aim of this article is to provide a comprehensive understanding of polysaccharides from Lilium plants and to serve as a basis for further research and development as therapeutic agents and multifunctional biomaterials.

Development of a joint derivatization protocol for the unequivocal identification of the monosaccharide composition in four dendrobium polysaccharides and free monosaccharide by GC-MS

The determination of monosaccharides is crucial for studying the structure of polysaccharides and the composition of free monosaccharides in living organisms. Based on previous derivatization gas chromatography-mass spectrometry (GC-MS) methods, we aimed to develop a novel analytical protocol for better quantifying monosaccharides. In this study, sugar alcohol acetylation, saccharonitrile acetylation, silylation and a combination of sugar alcohols acetylation and saccharonitrile acetylation were compared. The optimal method was verified with the monosaccharide determination of four polysaccharides and four free monosaccharides from Dendrobium. The results showed that the novel combined derivatization method was superior to the other three methods in terms of content analysis of monosaccharides. Furthermore, it possessed good linearity (all calibration curves showed relative coefficients ≥ 0.999), sensitivity, precision (relative standard deviation < 2%), and accuracy (recovery, 95.7-105%). Finally, the novel method established in this study was successfully employed in determining the monosaccharide composition of four polysaccharides and four free monosaccharide samples from Dendrobium.

High serum mannose in colorectal cancer: a novel biomarker of lymph node metastasis and poor prognosis

Background

Lymph node status is an important prognostic indicator and it significantly influences treatment decisions for colorectal cancer (CRC). The objective of this study was to evaluate the ability of serum monosaccharides in predicting lymph node metastasis (LNM) and prognosis.

Methods

High performance anion exchange chromatography coupled with pulsed amperometric detector (HPAEC-PAD) was used to quantify serum monosaccharides from 252 CRC patients. Receiver operating characteristic (ROC) curves were used to evaluate predictive performance of parameters. Predictors of LNM were evaluated by univariate and multivariate analyses. The prognostic role of the factors was evaluated by survival analysis.

Results

The levels of serum mannose (Man) and galactose (Gal) were significantly increased in patients with LNM (p <0.0001, p =0.0017, respectively). The area under the curves (AUCs) of Man was 0.8140, which was higher than carcinoembryonic antigen (CEA) (AUC =0.6523). Univariate and multivariate analyses demonstrated histologic grade (G3) (odds ratio [OR] =2.60, p =0.043), histologic grade (mucin-producing subtype) (odds ratio [OR] =3.38, p =0.032), lymphovascular invasion (LVI) (OR =2.42, p <0.01), CEA (>5ng/ml) (OR =1.85, p =0.042) and high Man (OR =2.65, p =0.006) to be independent risk factors of LNM. The survival analysis showed that the high serum Man was independent risk factor for poor prognosis in CRC patients (HR=1.75, p =0.004).

Conclusions

The Man is superior to CEA in prediction of LNM for CRC patients. Man is expected to be a predictor for LNM in CRC. High serum Man is associated with poor prognosis of CRC patients.

Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: An update for 2017-2018

This review is the tenth update of the original article published in 1999 on the application of matrix-assisted laser desorption/ionization mass spectrometry (MALDI) mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2018. Also included are papers that describe methods appropriate to glycan and glycoprotein analysis by MALDI, such as sample preparation techniques, even though the ionization method is not MALDI. Topics covered in the first part of the review include general aspects such as theory of the MALDI process, new methods, matrices, derivatization, MALDI imaging, fragmentation and the use of arrays. The second part of the review is devoted to applications to various structural types such as oligo- and poly-saccharides, glycoproteins, glycolipids, glycosides, and biopharmaceuticals. Most of the applications are presented in tabular form. The third part of the review covers medical and industrial applications of the technique, studies of enzyme reactions, and applications to chemical synthesis. The reported work shows increasing use of combined new techniques such as ion mobility and highlights the impact that MALDI imaging is having across a range of diciplines. MALDI is still an ideal technique for carbohydrate analysis and advancements in the technique and the range of applications continue steady progress.

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.

Recent advances in qualitative and quantitative analysis of polysaccharides in natural medicines: A critical review

Polysaccharides from natural medicines, being safe and effective natural mixtures, show great potential to be developed into botanical drugs. However, there is yet one polysaccharide-based case that has fulfilled the Botanical Guidance definition of a botanical drug product. One of the reasons is the analytical methods commonly used for qualitative and quantitative analysis of polysaccharides fall far behind the quality control criteria of botanical drugs. Here we systemically reviewed the recent advances in analytical methods. A critical evaluation of the strength and weaknesses of these methods was provided, together with possible solutions to the difficulties. Mass spectrometry with or without robust chromatographic separation was increasingly employed. And scientists have made significant progress in simplifying polysaccharide quantification by depolymerizing it into oligosaccharides. This oligosaccharides-based strategy is promising for qualitative and quantitative analysis of polysaccharides. And continuous efforts are still needed to develop a standardized quality control method that is specific, accurate, repeatable, and applicable for analyzing individual components in natural medicine formulas.

A review of sugar beet pectin-stabilized emulsion: extraction, structure, interfacial self-assembly and emulsion stability

In recent years, sugar beet pectin as a natural emulsifier has shown great potential in food and pharmaceutical fields. However, the emulsification performance depends on the molecular structure of sugar beet pectin, and the molecular structure is closely related to the extraction method. This review summarizes the extraction methods of pectin, structure characterization methods and the current research status of sugar beet pectin-stabilized emulsions. The structural characteristics of sugar beet pectin (such as degree of methylation, degree of acetylation, degree of blockiness, molecular weight, ferulic acid content, protein content, neutral sugar side chains, etc.) are of great significance to the emulsifying activity and stability of sugar beet pectin. Compared with traditional hot acid extraction method, ultrasonic-assisted extraction, microwave-assisted extraction, subcritical water-assisted extraction, induced electric field-assisted extraction and enzyme-assisted extraction can improve the yield of sugar beet pectin. At the same time, compared with harsh extraction conditions (too high temperature, too strong acidity, too long extraction time, etc.), mild extraction conditions can better preserve these emulsifying groups in sugar beet pectin molecules, which are beneficial to improve the emulsifying properties of sugar beet pectin. In addition, the interfacial self-assembly behavior of sugar beet pectin induced by the molecular structure is crucial to the long-term stability of the emulsion. This review provides a direction for extracting or modifying sugar beet pectin with specific structure and function, which is instructive for finding alternatives to gum arabic.

Glycosaminoglycan Quality Control by Monosaccharide Analysis

Glycosaminoglycans (GAGs) are heterogeneous biomacromolecules made by all animal cells with overlapping molecular weight and high negative charge densities, which make thorough separation of different types of GAGs and elimination of all GAG-binding proteins difficult. Even with the constant challenge of quality control, chondroitin sulfate, dermatan sulfate, heparan sulfate, and heparin glycosaminoglycans (GAGs) have been used as nutraceuticals and modern drugs for many years worldwide. Testing galactosamine in heparin has been added to the USP monograph after contaminated heparin event, but the general monosaccharide composition analysis has not been developed for GAG quality control purposes. Using a PCR-facilitated hydrolysis assay, the hydrolyzed GAG saccharides were labeled with 1-phenyl-3-methyl-5-pyrazolone (PMP) and quantified by high performance liquid chromatography (HPLC) coupled with mass spectrometry (MS). Glucosamine was found in both chondroitin sulfate and dermatan sulfate whereas galactosamine was observed in both heparan sulfate and heparin, indicating the cross contamination among different types of GAGs. Moreover, fucose was detected in chondroitin sulfate, dermatan sulfate, and heparan sulfate, and both fucose and mannose were detected in chondroitin sulfate, suggesting the co-presence of other types of glycans or novel fucosylated GAG structures. Furthermore, both the amount and structure of acid-resistant disaccharides provide distinguishable features for each type of GAGs at the same hydrolysis condition. Thus, monosaccharide analysis provides a practical and quantitative way for GAG quality control.

Extraction of mannoprotein from Saccharomyces cerevisiae and analysis of its chemical composition and molecular structure

The purpose of this study was to screen the method with the highest yield of mannoprotein (MP) without damaging their functional structure. The recovery rates of the extracts, protein, and mannose were determined along with the mannose/protein ratio, molecular weight and distribution, monosaccharide and amino acid compositions, and secondary structures of the three MP extracts to compare the extraction methods. The MP extracts recovery rate prepared by the thermal method was significantly higher (35.89%) than those obtained using fermentation (31.66%) and SDS treatment (19.77%). Three protein bands with similar molecular weights of 59, 47, and 34 kDa were detected in the MPs obtained via the different extraction methods. The thermally extracted MP has a broader molecular weight distribution. After purification, the proportion of mannose in the polysaccharide parts of the MPs increased from 6-7 to 90.4-91.3%. The essential amino acid content of the hot-extracted MP (170.07 mg/g) was the highest. The thermally extracted MP had similar secondary structural characteristics to that isolated at room temperature, and had a higher protein characteristic peak intensity. In general, the heating method to extract yeast mannoprotein is time-saving and efficient.

Quantitative Disaccharide Profiling of Glycosaminoglycans from Two Different Preparations by PMP and Deuterated PMP Labeling

Glycosaminoglycan (GAG) fine structures from the same animal cells and tissues are controlled not only by the biosynthetic and metabolic enzymes but also by other environmental factors, such as chemicals, growth factors, nutritional factors, and isolation procedures. To facilitate direct quantitative comparison of disaccharide compositions from different GAG preparations, several stable isotope labeling strategies have been developed. In this report, 1-phenyl-3-methyl-5-pyrazolone (PMP) and deuterated d5-PMP are used for differential disaccharide labeling and profiling of chondroitin sulfate GAG by high performance liquid chromatography (HPLC) coupled with mass spectrometry (MS).

Efficient Production of Scleroglucan by Sclerotium rolfsii and Insights Into Molecular Weight Modification by High-Pressure Homogenization

Scleroglucan is a non-ionic water-soluble polysaccharide, and has been widely used in the petroleum, food, medicine and cosmetics industries. Currently, scleroglucan is mainly produced by Sclerotium rolfsii. A higher level of scleroglucan (42.0 g/L) was previously obtained with S. rolfsii WSH-G01. However, the production of scleroglucan was reduced despite a higher glucose concentration remaining. Additionally, the molecular weight of scleroglucan was large, thus restricted its application. In this study, by adjusting the state of seeds inoculated, the degradation issue of scleroglucan during the fermentation process was solved. By comparing different fed-batch strategies, 66.6 g/L of scleroglucan was harvested by a two-dose fed-batch mode, with 53.3% glucose conversion ratio. To modify the molecular weight of scleroglucan, a combination method with HCl and high-pressure homogenization treatment was established. Finally, scleroglucan with molecular weight of 4.61 × 10⁵ Da was obtained. The developed approaches provide references for the biosynthesis and molecular weight modification of polysaccharides.

Production of Low Molecular Weight Chitosan and Chitooligosaccharides (COS): A Review

Chitosan is a biopolymer with high added value, and its properties are related to its molecular weight. Thus, high molecular weight values provide low solubility of chitosan, presenting limitations in its use. Based on this, several studies have developed different hydrolysis methods to reduce the molecular weight of chitosan. Acid hydrolysis is still the most used method to obtain low molecular weight chitosan and chitooligosaccharides. However, the use of acids can generate environmental impacts. When different methods are combined, gamma radiation and microwave power intensity are the variables that most influence acid hydrolysis. Otherwise, in oxidative hydrolysis with hydrogen peroxide, a long time is the limiting factor. Thus, it was observed that the most efficient method is the association between the different hydrolysis methods mentioned. However, this alternative can increase the cost of the process. Enzymatic hydrolysis is the most studied method due to its environmental advantages and high specificity. However, hydrolysis time and process cost are factors that still limit industrial application. In addition, the enzymatic method has a limited association with other hydrolysis methods due to the sensitivity of the enzymes. Therefore, this article seeks to extensively review the variables that influence the main methods of hydrolysis: acid concentration, radiation intensity, potency, time, temperature, pH, and enzyme/substrate ratio, observing their influence on molecular weight, yield, and characteristic of the product.

Analysis of monosaccharide composition of water-soluble polysaccharides from Codium fragile by ultra-performance liquid chromatography-tandem mass spectrometry

Codium fragile is a green alga belonging to Codiales family. The sulfated polysaccharides of this alga have anti-coagulation, antiviral, anti-angiogenesis, antioxidant, and immunoregulatory properties. In this study, we developed a reliable and rapid method for the analysis of 10 monosaccharides using ultra-performance liquid chromatography-tandem mass spectrometry in the negative electrospray ionization and multiple reaction monitoring mode. Monosaccharides, including two pentoses (xylose, arabinose); two deoxyhexoses (rhamnose, fucose); three hexoses (mannose, glucose, galactose); two hexuronic acids (glucuronic acid, galacturonic acid), and an N-acetyl-hexosamine (glucosamine), were derivatized using 1-phenyl-3-methyl-5-pyrazolone and simultaneously analyzed within 9 min. Optimization of the derivatization process, especially by using various 1-phenyl-3-methyl-5-pyrazolone concentrations, was studied. The calibration curves showed good linearity with a squared correlation coefficient > 0.995. The spiked recovery was determined to be 91.1-105.7% with the relative intra-day and inter-day standard deviations ranging from 2.58-6.71% and 3.15-7.67%, respectively. The limit of detection and limit of quantification for all 10 monosaccharides ranged from 0.02 to 0.10 μg/mL and 0.05 to 0.25 μg/mL, respectively. Using this method, the monosaccharides comprising the polysaccharides of Codium fragile were determined to be arabinose, galactose, and glucose.

Liquid Chromatography-Tandem Mass Spectrometry Approach for Determining Glycosidic Linkages

The structural analysis of carbohydrates remains challenging mainly due to the lack of rapid analytical methods able to determine and quantitate glycosidic linkages between the diverse monosaccharides found in natural oligosaccharides and polysaccharides. In this research, we present the first liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based method for the rapid and simultaneous relative quantitation of glycosidic linkages for oligosaccharide and polysaccharide characterization. The method developed employs ultrahigh-performance liquid chromatography coupled with triple quadrupole mass spectrometry (UHPLC/QqQ-MS) analysis performed in multiple reaction monitoring (MRM) mode. A library of 22 glycosidic linkages was built using commercial oligosaccharide standards. Permethylation and hydrolysis conditions along with LC-MS/MS parameters were optimized resulting in a workflow requiring only 50 μg of substrate for the analysis. Samples were homogenized, permethylated, hydrolyzed, and then derivatized with 1-phenyl-3-methyl-5-pyrazolone (PMP) prior to analysis by UHPLC/MRM-MS. Separation by C18 reversed-phase UHPLC along with the simultaneous monitoring of derivatized terminal, linear, bisecting, and trisecting monosaccharide linkages by mass spectrometry is achieved within a 15 min run time. Reproducibility, efficacy, and robustness of the method was demonstrated with galactan ( Lupin) and polysaccharides within food such as whole carrots. The speed and specificity of the method enables its application toward the rapid glycosidic linkage analysis of oligosaccharides and polysaccharides.