Derivatization of carbohydrates for GC and GC-MS analyses

Impact of glycosylation on viral vaccines

Glycosylation is the most prominent modification important for vaccines and its specific pattern depends on several factors that need to be considered when developing a new biopharmaceutical. Tailor-made glycosylation can be exploited to develop more effective and safer vaccines; for this reason, a deep understanding of both glycoengineering strategies and glycans structures and functions is required. In this review we discuss the recent advances concerning glycoprotein expression systems and the explanation of glycans immunomodulation mechanisms. Furthermore, we highlight how glycans tune the immunological properties among different vaccines platforms (whole virus, recombinant protein, nucleic acid), also comparing commercially available formulations and describing the state-of-the-art analytical technologies for glycosylation analysis. The whole review stresses the aspect of glycoprotein glycans as a potential tool to overcome nowadays medical needs in vaccine field.

Ion Chromatography and Related Techniques in Carbohydrate Analysis: A Review

Ion chromatography and related techniques have been the most popular separation methods used in the determination of organic and inorganic anions and cations, predominantly in water and wastewater samples. Making progress in their development and introducing new stationary phases, methods of detection and preparation of samples for analyses have given rise to the broadening of their analytical range. Nowadays, they are also used for substances that are not ionic by nature but can convert to such forms under certain conditions. These encompass, among others, carbohydrates, whose role and significance in humans' lives and environment is invaluable. Their presence in the air is mostly due to the industrial burning of biomass for energy production purposes. In addition, the content of sugars in plants, fruits and vegetables, constituting the base of human diets, affects our health condition. Given that, there is not only a need for their determination by means of routine methods but also for searching for novel analytical solutions. Based on literature data from the past decade, this paper presents the possibilities and examples of applications regarding ion chromatography and related techniques for the determination of carbohydrates in environmental samples, biomass and plants constituting food or raw materials for food production. Attention has been paid to the virtues and limitations of the discussed separation methods in this respect. Moreover, perspectives on their development have been defined.

A ginseng polysaccharide protects intestinal barrier integrity in high-fat diet-fed obese mice

A novel polysaccharide, GPH1, was extracted and isolated from ginseng. Structural analysis of GPH1 revealed a molecular weight of 7.321 × 105 Da and the presence of glucose and galactose components in a 30.2: 1 molar ratio. Results of methylation and NMR analyses indicated the GPH1 backbone consisted of →1)-α-Glc-(3→ and →1)-α-Glc-(6→. The anti-obesity activity of GPH1 was assessed by HFD-induced obesity mouse model. GPH1 was found to significantly reduced body weight, alleviated liver lipid accumulation and inflammatory damage. Meanwhile, GPH1 treatment increased the expression of tight junction proteins, including zonula occludens-1 (ZO-1) and claudin-1, while also regulating the intestinal microbiota of obese mice by promoting proliferation of beneficial bacteria with known anti-obesity effects, including s_Akkermansia muciniphila, s_Lactobacillus intestinalis, s_Lactobacillus reuteri, s_Streptococcus hyointestinalis, and s_Lactococcus garvieae. Our findings demonstrated that GPH1 is a practical natural dietary supplement with potential therapeutic effects on obesity.

Investigation of Hydrocolloid Plant Polysaccharides as Potential Candidates to Mimic the Functions of MUC5B in Saliva

The successful substitution of complex physiological fluids, such as human saliva, remains a major challenge in drug development. Although there are a large number of saliva substitutes on the market, their efficacy is often inadequate due to short residence time in the mouth, unpleasant mouthfeel, or insufficient protection of the teeth. Therefore, systems need to be identified that mimic the functions of saliva, in particular the salivary mucin MUC5B and the unique physiological properties of saliva. To this end, plant extracts known to contain hydrocolloid polysaccharides and to have mucus-forming properties were studied to evaluate their suitability as saliva substitutes. The aqueous plant extracts of Calendula officinalis, Fucus sp. thalli, and lichenan from Lichen islandicus were examined for composition using a range of techniques, including GC-MS, NMR, SEC, assessment of pH, osmolality, buffering capacity, viscoelasticity, viscoelastic interactions with human saliva, hydrocolloid network formation, and in vitro cell adhesion. For this purpose, a physiologically adapted adhesive test was developed using human buccal epithelial cells. The results show that lichenan is the most promising candidate to mimic the properties of MUC5B. By adjusting the pH, osmolality, and buffering capacity with K2HPO4, it was shown that lichenan exhibited high cell adhesion, with a maximum detachment force that was comparable to that of unstimulated whole mouth saliva.

Resolution and quantification of carbohydrates by enantioselective comprehensive two-dimensional gas chromatography

Carbohydrates, in particular the d-enantiomers of ribose, 2-deoxyribose, and glucose, are essential to life's informational biopolymers (RNA/DNA) and for supplying energy to living cells through glycolysis. Considered to be potential biosignatures in the search of past or present life, our capacity to detect and quantify these essential sugars is crucial for future space missions to the Moon, Mars or Titan as well as for sample-return missions. However, the enantioselective analysis of carbohydrates is challenging and both research and routine applications, are lacking efficient methods that combine highly sensitive and reproducible detection with baseline enantioselective resolution and reliable enantiomeric excess (ee) measurements. Here, we present four different derivatization strategies in combination with multidimensional gas chromatography coupled to a reflectron time-of-flight mass spectrometer (GC×GC-TOF-MS) for the enantioselective resolution of C3 to C6 carbohydrates potentially suitable for sample-return analyses. Full mass spectral interpretation and calibration curves for one single-step (cyclic boronate derivatives) and three two-step derivatization protocols (aldononitrile-acetate, hemiacetalization-trifluoroacetylation, and hemiacetalization-permethylation) are presented for concentrations ranging from 1 to 50 pmol μL⁻1 with correlation coefficients R2 > 0.94. We compared several analytical parameters including reproducibility, sensitivity (LOD and LOQ), overall separation, chiral resolution (RS), mass spectrum selectivity, stability during long term storage, and reliability of ee measurements to guide the application-dependent selection of optimal separation and quantification performance.

Combining thermosonication microstress and pineapple peel extract addition to achieve quality and post-acidification control in yogurt fermentation

This work investigated the effects of the combined use of thermosonication-preconditioned lactic acid bacteria (LAB) with the addition of ultrasound-assisted pineapple peel extracts (UU group) on the post-acidification potential, physicochemical and functional qualities of yogurt products, aimed at achieving prolonged preservation and enhancing functional attributes. Accordingly, the physical-chemical features, adhesion properties, and sensory profiles, acidification kinetics, the contents of major organic acids, and antioxidant activities of the differentially processed yogurts during refrigeration were characterized. Following a 14-day chilled storage process, UU group exhibited acidity levels of 0.5-2 oT lower than the control group and a higher lactose content of 0.07 mg/ml as well as unmodified adhesion potential, indicating that the proposed combination method efficiently inhibited post-acidification and delayed lactose metabolism without leading to significant impairment of the probiotic properties. The results of physicochemical analysis showed no significant changes in viscosity, hardness, and color of yogurt. Furthermore, the total phenolic content of UU-treated samples was 98 μg/mL, 1.78 times higher than that of the control, corresponding with the significantly lower IC50 values of DPPH and ABTS radical scavenging activities of the UU group than those of the control group. Observations by fluorescence inverted microscopy demonstrated the obvious adhesion phenomenon with no significant difference found among differentially prepared yogurts. The results of targeted metabolomics indicated the proposed combination strategy significantly modified the microbial metabolism, leading to the delayed utilization of lactose and the inhibited conversion into glucose during post-fermentation, as well as the decreased lactic acid production and a notable shift towards the formation of relatively weak acids such as succinic acid and citric acid. This study confirmed the feasibility of thermosonication-preconditioned LAB inocula, in combination with the use of natural active components from fruit processing byproducts, to alleviate post-acidification in yogurt and to enhance its antioxidant activities as well as simultaneously maintaining sensory features.

Extensive Analysis of Mulberry (Morus rubra L.) Polysaccharides with Different Maturities by Using Two-Step Extraction and LC/QqQ-MS

A primary challenge of polysaccharide analysis is the need for comprehensive extraction and characterization methods. In this study, mulberry polysaccharides at different maturities were fully extracted through a two-step process involving ethylenediaminetetraacetic acid (EDTA) and sodium hydroxide (NaOH), and their structures were determined by a combination analysis of monosaccharides and glycosidic linkages based on liquid chromatography triple quadrupole mass spectrometry (LC/QqQ-MS). The results indicate mulberry polysaccharides mainly contain highly branched pectic polysaccharides, (1,3,6)-linked glucan, xylan, and xyloglucan, but the content of different portions varies at different maturity stages. HG decreases from 19.12 and 19.14% (green mulberry) to 9.80 and 6.08% (red mulberry) but increases to 17.83 and 11.83% as mulberry transitioned from red to black. In contrast, the contents of glucan showed opposite trends. When mulberry turns red to black, the RG-I arabinan chains decrease from 47.75 and 28.86% to 13.16 and 12.72%, while the galactan side chains increase from 1.18 and 1.91 to 8.3 and 6.49%, xylan and xyloglucan show an increase in content. Overall, the two-step extraction combined with LC/QqQ-MS provides a new strategy for extensive analysis of complex plant polysaccharides.

Production and characterization of novel marine black yeast's exopolysaccharide with potential antiradical and anticancer prospects

The marine black yeasts are characterized by the production of many novel protective substances. These compounds increase their physiological adaptation to multi-extreme environmental stress. Hence, the exopolysaccharide (EPS) producing marine black yeast SAHE was isolated in this study. It was molecularly identified as Hortaea werneckii (identity 98.5%) through ITS1 and ITS4 gene sequencing analysis. The physicochemical properties of the novel SAHE-EPS were investigated through FTIR, GC-MS, TGA, ESM, and EDX analysis, revealing its heteropolysaccharide nature. SAHE-EPS was found to be thermostable and mainly consists of sucrose, maltose, cellobiose, lactose, and galactose. Furthermore, it exhibited an amorphous texture and irregular porous surface structure. SAHE-EPS showed significant antiradical activity, as demonstrated by the DPPH radical scavenging assay, and the IC50 was recorded to be 984.9 μg/mL. In addition, SAHE-EPS exhibited outstanding anticancer activity toward the A549 human lung cancer cell line (IC50 = 22.9 μg/mL). Conversely, it demonstrates minimal cytotoxicity toward the WI-38 normal lung cell line (IC50 = 203 μg/mL), which implies its safety. This study represents the initial attempt to isolate and characterize the chemical properties of an EPS produced by the marine black yeast H. werneckii as a promising antiradical and anticancer agent.

Assessing the effect of Maillard reaction products on the functionality and antioxidant properties of Amaranth-red seaweed blends

Plant-based proteins, represented by amaranth in our study, embrace a potential as an ingredient for the functional-food formulation. However, their efficacy is hindered by inherent limitations in solubility, emulsification, and antioxidant traits. The Maillard reaction, a complex chemical-process resulting in a diverse array of products, including Maillard conjugates and Maillard reaction products (MRPs), can employ variable effects on these specific attributes. To elucidate the influence of this reaction and the MRPs on the aforementioned properties, we used a complex blend of dehydrated seaweed Gracilaria and amaranth protein to create a conjugate-MRP blend. Our investigations revealed that the resultant incorporation enhanced solubility, emulsification, and antioxidant properties, while the intermediates formed did not progress to advanced glycation stages. This change is likely attributed to the dual effect of conjugates that altered the secondary protein structure, while the generation and/or preservation of MRPs post ultrasonication and spray drying enhanced its antioxidant potential.

Reactivity-based identification of oxygen containing functional groups of chemicals applied as potential classifier in non-target analysis

In this work, we developed a reactivity-based strategy to identify functional groups of unknown analytes, which can be applied as classifier in non-target analysis with gas chromatography. The aim of this strategy is to reduce the number of potential candidate structures generated for a molecular formula determined by high resolution mass spectrometry. We selected an example of 18 isomers with the molecular formula C12H10O2 to test the performance of different derivatization reagents, whereas our aim was to select mild and fast reaction conditions. Based on the results for the isomers, we developed a four-step workflow for the identification of functional groups containing oxygen.

Reduced Graphene Oxide/Organic Dye Composites for Bioelectroconversion of Saccharides: Application for Detection of Saccharides and α-Amylase Assessments

In this study, PQQ-dependent glucose dehydrogenase (PQQ-GDH) was immobilized onto reduced graphene oxide (rGO) modified with organic dyes from three different classes (acridine, arylmethane, and diazo); namely, neutral red (NR), malachite green (MG), and congo red (CR) formed three types of biosensors. All three rGO/organic dye composites were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy. The impact of three rGO/organic dye modifications employed in bioelectrocatalytic systems on changes in enzyme activity and substrate selectivity was investigated. The highest sensitivity of 39 µA/cm2 was obtained for 1 mM of glucose when a rGO_MG/PQQ-GDH biosensor was used. A significant improvement in the electrochemical response of biosensors was attributed to the higher amount of pyrrolic nitrogen groups on the surface of the rGO/organic dye composites. Modifications of rGO by NR and MG not only improved the surfaces for efficient direct electron transfer (DET) but also influenced the enzyme selectivity through proper binding and orientation of the enzyme. The accuracy of the biosensor's action was confirmed by the spectrophotometric analysis. Perspectives for using the proposed bioelectrocatalytic systems operating on DET principles for total or single monosaccharide and/or disaccharide determination/bioconversion systems or for diagnoses have been presented through examples of bioconversion of D-glucose, D-xylose, and maltose.

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.

Immunomodulatory Activity of Polysaccharides Isolated from Saussurea salicifolia L. and Saussurea frolovii Ledeb

The genus Saussurea has been used in the preparation of therapies for a number of medical problems, yet not much is known about the therapeutic high-molecular-weight compounds present in extracts from these plants. Since polysaccharides are important in immune modulation, we investigated the chemical composition and immunomodulatory activity of Saussurea salicifolia L. and Saussurea frolovii Ledeb polysaccharides. Water-soluble polysaccharides from the aerial parts of these plants were extracted using water at pHs of 2 and 6 and subsequently precipitated in ethanol to obtain fractions SSP2 and SSP6 from S. salicifolia and fractions SSF2 and SSF6 from S. frolovii. The molecular weights of fractions SSP2, SSP6, SFP2, and SFP6 were estimated to be 143.7, 113.2, 75.3, and 64.3 kDa, respectively. The polysaccharides from S. frolovii contained xylose (67.1-71.7%) and glucose (28.3-32.9%), whereas the polysaccharides from S. frolovii contained xylose (63.1-76.7%), glucose (11.8-19.2%), galactose (4.7-8.3%), and rhamnose (6.8-9.4%). Fractions SSP2, SSP6, and SFP2 stimulated nitric oxide (NO) production by murine macrophages, and NO production induced by SSP2, SSP6, and SFP2 was not inhibited by polymyxin B treatment of the fractions, whereaspolymyxin B treatment diminished the effects of SFP6, suggesting that SFP6 could contain lipopolysaccharide (LPS). The LPS-free fractions SSP2, SSP6, and SFP2 had potent immunomodulatory activity, induced NO production, and activated transcription factors NF-κB/AP-1 in human monocytic THP-1 cells and cytokine production by human MonoMac-6 monocytic cells, including interleukin (IL)-1α, IL-1β, IL-6, granulocyte macrophage colony-stimulating factor (GM-CSF), interferon-γ, monocyte chemotactic protein 1 (MCP-1), and tumor necrosis factor (TNF). These data suggest that at least part of the beneficial therapeutic effects reported for water extracts of the Saussurea species are due to the modulation of leukocyte functions by polysaccharides.

Metabolic Fingerprinting of Different Sideritis Taxa Infusions and Their Neurogenic Activity

Over the last years, Sideritis extracts were shown to improve memory. However, their potential to promote the generation of new neurons, starting with the neuronal differentiation of neural stem cells, remains unexplored. Therefore, the present study aimed to evaluate the neurogenic effects of different Sideritis infusions in neural stem and precursor cells and their impact on cell viability. Moreover, the metabolic fingerprints were recorded using LC-DAD, LC-HRESIMS, and GC-MS. The neurogenic potential of infusions of the eight Sideritis taxa tested was as potent as the classical neuronal inducer combination of retinoic acid and valproic acid. Further cytotoxicity assays revealed that the IC50 values of the extracts were between 163 and 322 µg/mL. Hierarchical cluster analyses of the metabolic fingerprints unveiled that the two Sideritis taxa with the lowest IC50 values were the most divergent in the analytical techniques used. As the analysis focused on polyphenols, it is reasonable to assume that these compounds are responsible for the effect on the cell viability of SH-SY5Y neuroblastoma cells. This study is the first report on the neurogenic potential of Sideritis taxa and might support the use of Sideritis herbal preparations in the context of neurodegenerative diseases.

Application of chromatography in purification and structural analysis of natural polysaccharides: A review

Polysaccharides are widely distributed in natural sources from monocytic microorganisms to higher animals, and are found in a variety of biological activities in recent decades. Natural polysaccharides have the characteristics of large molecular weight, diverse composition, and complex structure, so their purification and structural analysis are difficult issues in research. Chromatography as a powerful separation technique, plays an irreplaceable role in the separation and structural analysis of natural polysaccharides, especially in the purification of polysaccharides, the separation of hydrolysates, and the analysis of monosaccharide composition. The separation mechanisms and application of different chromatographic methods in the studies of polysaccharides were summarized in this review. Moreover, the advantages and drawbacks of various chromatography methods were discussed as well.

Acetylation in Ionic Liquids Dramatically Increases Yield in the Glycosyl Composition and Linkage Analysis of Insoluble and Acidic Polysaccharides

Glycosyl composition and linkage analyses are important first steps toward understanding the structural diversity and biological importance of polysaccharides. Failure to fully solubilize samples prior to analysis results in the generation of incomplete and poor-quality composition and linkage data by gas chromatography-mass spectrometry (GC-MS). Acidic polysaccharides also do not give accurate linkage results, because they are poorly soluble in DMSO and tend to undergo β-elimination during permethylation. Ionic liquids can solubilize polysaccharides, improving their derivatization and extraction for analysis. We show that water-insoluble polysaccharides become much more amenable to chemical analysis by first acetylating them in an ionic liquid. Once acetylated, these polysaccharides, having been deprived of their intermolecular hydrogen bonds, are hydrolyzed more readily for glycosyl composition analysis or methylated more efficiently for glycosyl linkage analysis. Acetylation in an ionic liquid greatly improves composition analysis of insoluble polysaccharides when compared to analysis without acetylation, enabling complete composition determination of normally recalcitrant polysaccharides. We also present a protocol for uronic acid linkage analysis that incorporates this preacetylation step. This protocol produces partially methylated alditol acetate derivatives in high yield with minimal β-elimination and gives sensitive linkage results for acidic polysaccharides that more accurately reflect the structures being analyzed. We use important plant polysaccharides to show that the preacetylation step leads to superior results compared to traditional methodologies.

Antibacterial activity of exopolysaccharide produced by bee gut-resident Enterococcus sp. BE11 against marine fish pathogens

BACKGROUND

In recent years, the demand for innovative antimicrobial agents has grown, considering the growing problem of antibiotic resistance in aquaculture. Adult Apis mellifera honeybees' gut represents an outstanding habitat to isolate novel lactic acid bacteria (LAB) able to produce prominent antimicrobial agents.

METHODS

In the current study, twelve LAB were isolated and purified from the gut of adult Apis mellifera. The isolates were screened for exopolysaccharide (EPS) production. The most promising isolate BE11 was identified biochemically and molecularly using 16 S rRNA gene sequence analysis as Enterococcus sp. BE11 was used for the mass production of EPS. The partially purified BE11-EPS features were disclosed by its physicochemical characterization. Moreover, the antimicrobial activity of BE11 cell free supernatant (CFS) and its EPS was investigated against some fish pathogens namely, Pseudomonas fluorescens, Streptococcus agalactiae, Aeromonas hydrophila, Vibrio sp. and Staphylococcus epidermidis using well-cut diffusion method.

RESULTS

The physicochemical characterization of BE11-EPS revealed that the total carbohydrate content was estimated to be ~ 87%. FTIR and NMR analysis ascertained the presence of galactose and glucose residues in the EPS backbone. Moreover, the GC-MS analysis verified the heterogeneous nature of the produced BE11-EPS made up of different monosaccharide moieties: galactose, rhamnose, glucose, arabinose sugar derivatives, and glucuronic acid. BE11 CFS and its EPS showed promising antimicrobial activity against tested pathogens as the inhibition zone diameters (cm) ranged from 1.3 to 1.7 and 1.2-1.8, respectively.

CONCLUSION

The bee gut-resident Enterococcus sp. BE11, CFS, and EPS were found to be promising antimicrobial agents against fish pathogens and biofilm producers affecting aquaculture. To the best of our knowledge, this is the first study to purify and make a chemical profile of an EPS produced by a member of the bee gut microbiota as a potential inhibitor for fish pathogens.

A universal UHPLC-CAD platform for the quantification of polysaccharide antigens

Several glycoconjugate-based vaccines against bacterial infections have been developed and licensed for human use. Polysaccharide (PS) analysis and characterization is therefore critical to profile the composition of polysaccharide-based vaccines. For PS content quantification, the majority of Ultra High Performance Liquid Chromatography (UHPLC) methods rely on the detection of selective monosaccharides constituting the PS repeating unit, therefore requiring chemical cleavage and tailored development: only a few methods directly quantify the intact PS. The introduction of charged aerosol detector (CAD) technology has improved the response of polysaccharide analytes, offering greater sensitivity than other detector sources (e.g., ELSD). Herein, we report the development of a universal UHPLC-CAD method (UniQS) for the quantification and quality evaluation of polysaccharide antigens (e.g., Streptococcus Pneumoniae, Neisseria meningitidis and Staphylococcus aureus). This work laid the foundation for a universal UHPLC-CAD format that could play an important role in future vaccine research and development helping to reduce time, efforts, and costs.

Fractionation of Aspen Wood to Produce Microcrystalline, Microfibrillated and Nanofibrillated Celluloses, Xylan and Ethanollignin

A new method for extractive-catalytic fractionation of aspen wood to produce microcrystalline (MCC), microfibrillated (MFC), nanofibrilllated (NFC) celluloses, xylan, and ethanollignin is suggested in order to utilize all of the main components of wood biomass. Xylan is obtained with a yield of 10.2 wt.% via aqueous alkali extraction at room temperature. Ethanollignin was obtained with a yield of 11.2 wt.% via extraction with 60% ethanol from the xylan-free wood at 190 °C. The lignocellulose residue formed after the extraction of xylan and ethanollignin was subjected to catalytic peroxide delignification in the acetic acid-water medium at 100 °C in order to obtain microcrystalline cellulose. MCC is hydrolyzed with 56% sulfuric acid and treated with ultrasound to produce microfibrillated cellulose and nanofibrillated cellulose. The yields of MFC and NFC were 14.4 and 19.0 wt.%, respectively. The average hydrodynamic diameter of NFC particles was 36.6 nm, the crystallinity index was 0.86, and the average zeta-potential was 41.5 mV. The composition and structure of xylan, ethanollignin, cellulose product, MCC, MFC, and NFC obtained from aspen wood were characterized using elemental and chemical analysis, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) analyses, Gas chromatography (GC), Gel permeation-chromatography (GPC), Scanning electron microscopy (SEM), Atomic force microscopy (AFM), Dynamic light scattering (DLS), Thermal gravimetric analysis (TGA).

Comprehensive metabolomics-based analysis of sugar composition and content in berries of 18 grape varieties

Xinjiang is the largest grape-producing region in China and the main grape cultivation area in the world. The Eurasian grape resources grown in Xinjiang are very rich in diversity. The sugar composition and content are the main factors that determine the quality of berries. However, there are currently no systematic reports on the types and contents of sugars in grapes grown in Xinjiang region. In this research, we evaluated the appearance and fruit maturity indicators of 18 grape varieties during fruit ripening and determined their sugar content using GC-MS. All cultivars primarily contained glucose, D-fructose, and sucrose. The glucose content in varieties varied from 42.13% to 46.80% of the total sugar, whereas the fructose and sucrose contents varied from 42.68% to 50.95% and 6.17% to 12.69%, respectively. The content of trace sugar identified in grape varieties varied from 0.6 to 2.3 mg/g. The comprehensive assessment by principal component analysis revealed strong positive correlations between some sugar components. A comprehensive study on the content and types of sugar will provide the foundation to determine the quality of grape cultivars and effective ways to utilize resources to improve sugar content through breeding.

Simultaneous microwave-assisted extraction of bioactive compounds from aged garlic

In this work, the simultaneous extraction of bioactives (organosulfur compounds, such as S-allyl-L-cysteine (SAC), carbohydrates, such as neokestose and neonystose, and total phenolic compounds) from aged garlic has been optimized for the first time to obtain multifunctional extracts for further application as food ingredients. Analytical methods using liquid chromatography coupled to mass spectrometry (HPLC-MS) and by hydrophilic interaction liquid chromatography with evaporative light scattering detection (HILIC-ELSD) were also previously optimized. High sensitivity (limits of detection between 0.013 and 0.77 µg mL^-1) and appropriate repeatability (< 12%) and accuracy (> 92%) for the analysis of bioactives were achieved. After selecting water as the extraction solvent and microwave-assisted extraction (MAE) as the most efficient technique, operation conditions were optimized using a Box-Behnken experimental design (60 min; 120 °C; 0.05 g mL^-1; 1 cycle) to maximize the content of bioactives from different aged garlic samples. Regarding organosulfur compounds, only SAC (traces-2.32 mg g^-1 dry sample) and cycloalliin (1.23-3.01 mg g^-1 dry sample) were detected in all samples, while amino acids such as arginine (0.24-3.45 mg g^-1 dry sample) and proline (0.43-3.91 mg g^-1 dry sample) were, in general, the most abundant. Bioactive carbohydrates (from trisaccharides to nonasaccharides) were only detected in fresh garlic and aged garlic processed under mild conditions, whereas all garlic extracts showed antioxidant activity. The developed MAE methodology is shown as a successful alternative to other procedures for the simultaneous extraction of aged garlic bioactives intended by the food and nutraceutical industries, among others.

Construction and Performance Evaluation of Nicandra physalodes (Linn.) Gaertn. Polysaccharide-Based Nanogel

The nanogels made from these polysaccharides and their derivatives are often used to construct drug delivery systems owing to their biocompatible, biodegradable, non-toxic, water-soluble, and bioactive characteristics. In this work, a novel pectin with unique gelling properties was extracted from the seed of Nicandra physalodes (NPGP). The structural research indicated that NPGP was a low methoxyl pectin with a high content of galacturonic acid. NPGP-based nanogels (NGs) were accomplished employing the water in oil (W/O) nano-emulsion method. The cysteamine containing reduction-responsive bond and integrin-targeting RGD peptide were also grafted onto NPGP. The anti-tumor drug doxorubicin hydrochloride (DOX) was loaded during the formation of NGs, and the performance of DOX delivery was studied. The NGs were characterized by UV-vis, DLS, TEM, FT-IR, and XPS. The results showed that the prepared NGs were nanosized (167.6 ± 53.86 nm), had excellent encapsulation efficiency (91.61 ± 0.85%), and possessed a fine drug loading capacity (8.40 ± 0.16%). The drug release experiment showed that DOX@NPGP-SS-RGD had good redox-responsive performance. Furthermore, the results of cell experiments revealed good biocompatibility of prepared NGs, along with selective absorption by HCT-116 cells through integrin receptor-mediated endocytosis to play an anti-tumor effect. These studies indicated the potential application of NPGP-based NGs as targeted drug delivery systems.

The use of gas chromatography - high resolution mass spectrometry for suspect screening and non-targeted analysis of per- and polyfluoroalkyl substances

This study is a workflow development for the analysis, identification, and categorization of per- and polyfluoroalkyl substances (PFAS) using gas chromatography-high resolution mass spectrometry (GC-HRMS) with non-targeted analysis (NTA) and suspect screening techniques. The behavior of various PFAS in a GC-HRMS was studied with regards to retention indices, ionization susceptibility, fragmentation patterns, etc. A custom PFAS database was constructed from 141 diverse PFAS. The database contains mass spectra from electron ionization (EI) mode, as well as MS and MS/MS spectra from positive and negative chemical ionization (PCI and NCI, respectively) modes. Common fragments of PFAS were identified across a diverse set of 141 PFAS analyzed. A workflow for suspect screening of PFAS and partially fluorinated products of incomplete combustion/destruction (PICs/PIDs) was developed which utilized both the custom PFAS database and external databases. PFAS and other fluorinated compounds were identified in both a challenge sample (designed to test the identification workflow) and incineration samples suspected to contain PFAS and fluorinated PICs/PIDs. The challenge sample resulted in a 100% true positive rate (TPR) for PFAS which were present in the custom PFAS database. Several fluorinated species were tentatively identified in the incineration samples using the developed workflow.

Slow digestion properties of long-sized isomaltooligosaccharides synthesized by a transglucosidase from Thermoanaerobacter thermocopriae

Isomaltooligosaccharides (IMOs) are widely used as prebiotic ingredients that promote colon health; however, recent studies revealed that these are slowly hydrolyzed to glucose within the small intestine. Here, novel α-glucans with a higher number of α-1,6 linkages were synthesized from maltodextrins using the Thermoanaerobacter thermocopriae-derived transglucosidase (TtTG) to decrease susceptibility to hydrolysis and improve slow digestion properties. The synthesized long-sized IMOs (l-IMOs; 70.1% of α-1,6 linkages), comprising 10-12 glucosyl units, exhibited slow hydrolysis to glucose when compared to commercial IMOs under treatment with mammalian α-glucosidase level. In male mice, the ingestion of l-IMOs significantly decreased the post-prandial glycemic response compared to other samples (p < 0.05). Therefore, enzymatically synthesized l-IMOs can be applied as functional ingredients for the modulation of blood glucose homeostasis in obesity, Type 2 diabetes, and other chronic diseases.

Determination of the intermediates in glycolysis and tricarboxylic acid cycle with an improved derivatization strategy using gas chromatography-mass spectrometry in complex samples

Traditional Chinese medicine (TCM) is recognized as a complex matrix, and improved analytical methods are crucial to extract the key indicators and depict the interaction and alteration of the complex matrix. Shenqi Fuzheng Injection (SQ), a water extract of Radix Codonopsis and Radix Astragali, has demonstrated preventative effects on myotube atrophy induced by chemotherapeutic agents. To achieve the improved analytical capability of complex biological samples, we established a highly reproducible, sensitive, specific, and robust gas chromatography-tandem mass spectrometry (GC-MS) method to detect glycolysis and tricarboxylic acid (TCA) cycle intermediates with optimized factors in the extraction and derivatization process. Our method detected fifteen metabolites and covered most intermediate metabolites in glycolysis and TCA cycles, including glucose, glucose-6-phosphate, fructose-6-phosphate, dihydroxyacetone phosphate, 3-diphosphoglycerate, phosphoenolpyruvate, pyruvate, lactate, citrate, cis-aconitate, isocitrate, α-ketoglutarate, succinate, fumarate, and malate. Through methodological verification of the method, it was found that the linear correlation coefficients of each compound in the method were greater than 0.98, all of which had lower limits of quantification, the recovery rate was 84.94-104.45%, and the accuracy was 77.72-104.92%. The intraday precision was 3.72-15.37%, the interday precision was 5.00-18.02%, and the stability was 7.85-15.51%. Therefore, the method has good linearity, accuracy, precision, and stability. The method was further applied to study the attenuating effects of the SQ in a chemotherapeutic agents-induced C2C12 myotube atrophy model to evaluate the changes in the tricarboxylic acid cycle and glycolytic products under the action by the complex systems of TCM and disease model. Our study provided an improved method to explore TCM's pharmacodynamic constituents and action mechanisms.

Gas Chromatography with Flame-Ionization Detection-Based Analysis of Sugar Contents in Korean Agricultural Products for Patients with Galactosemia

Patients with galactosemia accumulate galactose in their bodies, requiring a lifelong galactose-restricted diet. Therefore, accurate information on the galactose content in commercial agro-food resources is essential. The HPLC method generally used for sugar analysis has low separation and detection sensitivity. Here, we sought to establish an accurate analytical method for determining the galactose content in commercial agro-food resources. To that aim, we employed gas chromatography with flame-ionization detection to detect trimethylsilyl-oxime (TMSO) sugar derivatives (concentration: ≤0.1 mg/100 g). The galactose content in 107 Korean agro-food resources reflecting intake patterns was then analyzed. The galactose content in steamed barley rice was 5.6 mg/100 g, which was higher than that in steamed non-glutinous and glutinous rice. Moist-type and dry-type sweet potatoes, blanched zucchini, and steamed Kabocha squash had high galactose content (36.0, 12.8, 23.1, and 61.6 mg/100 g, respectively). Therefore, these foods are detrimental to patients with galactosemia. Among fruits, avocado, blueberry, kiwi, golden kiwifruit, and sweet persimmon had galactose contents of ≥10 mg/100 g. Dried persimmon had 132.1 mg/100 g and should therefore be avoided. Mushrooms, meat, and aquatic products showed low galactose content (≤10 mg/100 g), making them safe. These findings will help patients to manage their dietary galactose intake.

Structural elucidation of the exopolysaccharide from Streptococcus thermophilus XJ53 and the effect of its molecular weight on immune activity

EPS53, a homogeneous exopolysaccharide (EPS) was isolated from Streptococcus thermophiles XJ53 fermented in skimmed milk via anion exchange column chromatography. The relative molecular weight of EPS53 was above 6.7 × 10⁵ g/mol; its repeating structural unit of EPS53 consisted of β-T-Galp, β-1,3-Galf, α-1,3-Glcp and β-1,3,6-Glcp residues in a molar ratio of 1:1:1:1, with β-T-Galp attached to the O-6 position of β-1,3,6-Glcp，identical to the EPS produced from S. thermophilus SFi39. EPS53-D, purified under similar conditions as EPS53 except for the deproteinization of trichloroacetic acid (TCA), had a lower molecular weight but the same repeating structural unit. The effects of EPS53 and EPS53-D on proliferation, phagocytosis and nitric oxide (NO) release of macrophage RAW264.7 were compared. EPS53 exhibited stronger immune activity than EPS53-D, suggesting that the molecular weight might have an important effect on the activity of EPS molecules. Treatment with TCA might affect the activities of native EPSs produced by fermentation.

Preparation, Structural Characterisation, and Bioactivities of Fructans: A Review

Polysaccharides are important components of higher plants and have attracted increasing attention due to their many nutraceutical benefits in humans. Fructans, heterogeneous fructose polymers that serve as storage carbohydrates in various plants, represent one of the most important types of natural polysaccharides. Fructans have various physiological and therapeutic effects, which are beneficial to health, and have the ability to prevent or treat various diseases, allowing their wide use in the food, nutraceutical, and pharmaceutical industries. This article reviews the occurrence, metabolism, preparation, characterisation, analysis, and bioactivity of fructans. Further, their molecular weight, monosaccharide composition, linkages, and structural determination are described. Taken together, this review provides a theoretical foundation for further research into the structure-function relationships of fructans, as well as valuable new information and directions for further research and application of fructans in functional foods.

HPTLC-based fingerprinting: An alternative approach for fructooligosaccharides metabolism profiling

Fructans are categorized as fructose-based metabolites with no more than one glucose in their structure. Agave species possess a mixture of linear and ramified fructans with different degrees of polymerization. Among them, fructooligosaccharides are fructans with low degree of polymerization which might be approachable by high performance thin layer chromatography (HPTLC). Thus, this study used two emblematic Agave species collected at different ages as models to explore the feasibility of HPTLC-based fingerprinting to characterize fructooligosaccharides (FOS) production, accumulation, and behavior through time. To do so, high performance anion exchange was also used as analytical reference to determine the goodness and robustness of HPTLC data. The multivariate data analysis showed separation of samples dictated by species and age effects detected by both techniques. Moreover, linear correlations between the increase of the age in agave and their carbohydrate fraction was established in both species by both techniques. Oligosaccharides found to be correlated to species and age factors, these suggest changes in specific carbohydrate metabolism enzymes. Thus, HPTLC was proven as a complementary or stand-alone fingerprinting platform for fructooligosaccharides characterization in biological mixtures. However, the type of derivatizing reagent and the extraction color channel determined the goodness of the model used to scrutinize agavin fructooligosaccharides (aFOS).

Characterization and in vitro anticancer potential of exopolysaccharide extracted from a freshwater diatom Nitzschia palea (Kütz.) W.Sm. 1856

Diatoms are photoautotrophic microalgae classified under class Bacillariophyceae, engulfed by hard silicate frustules, which give mechanical support and protection from bacterial infections. They exude polysaccharides extracellularly that help them with their gliding motion (locomotion). However, the bioactivity of such compounds was least explored from freshwater diatoms. In the present study, a single species of pennate diatom identified as Nitzschia palea was isolated and molecularly characterized by 18S rRNA smaller subunit gene (partial) sequencing and submitted to GenBank NCBI and accession number retrieved as ON360983. Based on logarithmic growth curve analysis, the exponential phase was obtained from 3rd to 4th day of diatom culture. The exopolysaccharide was extracted by the hot-water extraction method, and characterized by FT-IR. The total yield of exopolysaccharide from Nitzschia palea was estimated as 1.56 mg in 100 mL of culture after 7 days of incubation. The estimated carbohydrate content was 51.35 µg/100 µL. The monosaccharide constituents were determined by acid hydrolysis of exopolysaccharide, silylation (derivatization), followed by GC-MS analysis and tabulated. The extracted exopolysaccharide was evaluated for its anti-cancer potential against the Human Adenocarcinoma lung cancer cell line (A549) and the estimated IC₅₀ value was 62.64 µg/mL. Acridine orange staining assay and DNA fragmentation assay also confirmed the apoptotic activity of exopolysaccharide derived from the diatom Nitzschia palea.

A Sensitive GC-MS Method for Quantitation of Lipid A Backbone Components and Terminal Phosphate Modifications

Lipid A, the hydrophobic anchor of lipopolysaccharide (LPS) present in the outer membrane of Gram-negative bacteria, serves as a target for cationic antimicrobial peptides, such as polymyxins. Membrane stress from polymyxins results in activation of two-component regulatory systems that produce lipid A modifying enzymes. These enzymes add neutral moieties, such as aminoarabinose (AraN) and ethanolamine (EtN) to lipid A terminal phosphates that mask the phosphate's negative charge and inhibit electrostatic interaction with the cationic polymyxins. Currently, these modifications may be detected by MALDI-TOF MS; however, this analysis is only semiquantitative. Herein we describe a GC-MS method to quantitate lipid A backbone components, glucosamine (GlcN) and inorganic phosphate (Pi), along with terminal phosphate modifications AraN and EtN. In this assay, lipid A is isolated from Gram-negative bacterial samples, hydrolyzed into its individual moieties, and derivatized via methoximation followed by silylation prior to analysis via GC-MS. Changes in AraN and EtN quantity were characterized using a variety of regulatory mutants of Salmonella, revealing differences that were not detected using MALDI-TOF MS analysis. Additionally, an increase in the abundance of AraN and EtN modifications were observed when resistant Enterobacter and Escherichia coli strains were grown in the presence of colistin (polymyxin E). Lastly, increased levels of Pi were found in bisphosphorylated lipid A compared to monophosphorylated lipid A samples. Because lipid A modifications serve as indicators of polymyxin resistance in Gram-negative bacteria, this method provides the capacity to monitor polymyxin resistance by quantification of lipid A modification using GC-MS.

Non-starch polysaccharides in beer and brewing: A review of their occurrence and significance

It has become apparent that beer (both alcoholic and nonalcoholic) contains appreciable amounts of non-starch polysaccharides, a broad subgroup of dietary fiber. It is worth noting that the occurrence of non-starch polysaccharides in alcoholic beer does not imply this should be consumed as a source of nutrition. But the popularity of nonalcoholic beer is growing, and the lessons learnt from non-starch polysaccharides in brewing can be largely translated to nonalcoholic beer. For context, we briefly review the origins of dietary fiber, its importance within the human diet and the significance of water-soluble dietary fiber in beverages. We review the relationship between non-starch polysaccharides and brewing, giving focus to the techniques used to quantify non-starch polysaccharides in beer, how they affect the physicochemical properties of beer and their influence on the brewing process. The content of non-starch polysaccharides in both regular and low/nonalcoholic beer ranges between 0.5 - 4.0 g/L and are predominantly composed of arabinoxylans and β-glucans. The process of malting, wort production and filtration significantly affect the soluble non-starch polysaccharide content in the final beer. Beer viscosity and turbidity are strongly associated with the content of non-starch polysaccharides.

Application of accelerated heteronuclear single quantum coherence experiments to the rapid quantification of monosaccharides and disaccharides in dairy products

Monosaccharides and disaccharides are important dietary components, but if insufficiently metabolized by some population subgroups, they are also linked to disease patterns. Thus, the correct analytical identification, quantification, and labeling of these food components are crucial to inform and potentially protect consumers. Enzymatic assays and high-performance anion-exchange chromatography with pulsed amperometric detection are established methods for the quantification of monosaccharides and disaccharides that, however, require long measuring times (60-180 min). Accelerated methods for the identification and quantification of the nutritionally relevant monosaccharides and disaccharides d-glucose, d-galactose, d-fructose, sucrose, lactose, and maltose were therefore developed. To realize this goal, the NMR experiments HSQC (heteronuclear single quantum coherence) and acceleration by sharing adjacent polarization (ASAP)-HSQC were applied. Measurement times were reduced to 27 and 6 min, respectively, by optimizing the interscan delay and applying non-uniform sampling. The optimized methods were used to quantify d-glucose, d-galactose, d-fructose, sucrose, and lactose in various dairy products. Results of the HSQC and ASAP-HSQC methods are equivalent to the results of the reference methods in terms of both precision and accuracy, demonstrating that these methods can be used to correctly analyze nutritionally relevant monosaccharides and disaccharides in short times.

Quantification of Isomaltulose in Food Products by Using Heteronuclear Single Quantum Coherence NMR-Experiments

Isomaltulose is a commonly used sweetener in sports nutrition and in products intended for consumption by diabetics. Because previously established chromatographic methods for quantification of isomaltulose suffer from long analysis times (60–210 min), faster quantitative approaches are required. Here, an HSQC (heteronuclear single quantum coherence) experiment with reduced interscan delay was established in order to quantify isomaltulose next to potential additional sugars such as d-glucose, d-fructose, d-galactose, sucrose, lactose, and maltose in 53 min. By using HSQC coupled to non-uniform sampling (NUS) as well as ASAP-HSQC (acceleration by sharing adjacent polarization), analysis times were reduced to a few minutes. Application of NUS-HSQC with reduced interscan delay takes 27 min, resulting in accurate and precise data. In principle, application of ASAP-HSQC approaches (with analysis times as low as 6 min) can be used; however, precision data may not suffice all applications.

Structure and function of non-digestible carbohydrates in the gut microbiome

Together with proteins and fats, carbohydrates are one of the macronutrients in the human diet. Digestible carbohydrates, such as starch, starch-based products, sucrose, lactose, glucose and some sugar alcohols and unusual (and fairly rare) α-linked glucans, directly provide us with energy while other carbohydrates including high molecular weight polysaccharides, mainly from plant cell walls, provide us with dietary fibre. Carbohydrates which are efficiently digested in the small intestine are not available in appreciable quantities to act as substrates for gut bacteria. Some oligo- and polysaccharides, many of which are also dietary fibres, are resistant to digestion in the small intestines and enter the colon where they provide substrates for the complex bacterial ecosystem that resides there. This review will focus on these non-digestible carbohydrates (NDC) and examine their impact on the gut microbiota and their physiological impact. Of particular focus will be the potential of non-digestible carbohydrates to act as prebiotics, but the review will also evaluate direct effects of NDC on human cells and systems.

Stable-Isotope Dilution GC-MS Measurement of Metformin in Human Serum and Urine after Derivatization with Pentafluoropropionic Anhydride and Its Application in Becker Muscular Dystrophy Patients Administered with Metformin, l-Citrulline, or Their Combination

Metformin (N,N-dimethylguanylguanidine) is one of the most prescribed drugs with pleiotropic, exerted in part by not fully elucidated mechanisms of action. We developed and validated a gas chromatography-mass spectrometry (GC-MS) method for the quantitative analysis of metformin (metformin-d₀) in 10-µL aliquots of human serum and urine using N,N-[dimethylo-²H₆]guanylguanidine (metformin-d₆) as the internal standard. The method involves evaporation of the samples to dryness, derivatization with pentafluoropropionic (PFP) anhydride in ethyl acetate (30 min, 65 °C), and extraction into toluene. The negative-ion chemical ionization GC-MS spectra of the PFP derivatives contain a single intense ion with mass-to-charge (m/z) ratios of m/z 383 for metformin-d₀ and m/z 389 for metformin-d₆. Our results suggest that all amine/imine groups of metformin-d₀ and metformin-d₆ are converted to their N,N,N-tripentafluoropropionyl derivatives, which cyclize to form a symmetric triazine derivative, of which the non-ring amine group is amidated. Quantification was performed by selected-ion monitoring (SIM) of m/z 383 and m/z 389. Upon validation, the method was applied to determine serum and urine metformin concentrations in 19 patients with Becker muscular dystrophy (BMD). Serum and urine samples were collected at baseline (Visit I), after six weeks of supplementation (Visit II) with metformin (3 × 500 mg/d; metformin group; n = 10) or l-citrulline (3 × 1500 mg/d; citrulline group; n = 9) followed by a six-week supplementation with 3 × 500 mg/d of metformin plus 3 × 1500 mg/d l-citrulline. At Visit I, the metformin concentration in the serum and urine was very low in both groups. The metformin concentrations in the serum and urine of the patients who first took metformin (MET group) were higher at Visit II and Visit III. The metformin concentration in the serum and urine samples of the patients who first took l-citrulline (CITR group) were higher at Visit III. The serum and urine concentrations of metformin were insignificantly lower in the CITR group at Visit III. The mean fractional excretion (FE) rate of metformin was 307% (Visit II) and 322% (Visit III) in the MET group, and 290% in the CITR group (Visit III). This observation suggests the accumulation of metformin in the kidney and its secretion in the urine. The GC-MS is suitable to measure reliably circulating and excretory metformin in clinical settings.

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.

Production and Characterization of Exopolysaccharide From Newly Isolated Marine Probiotic Lactiplantibacillus plantarum EI6 With in vitro Wound Healing Activity

Because of its safety, biological activities, and unique properties, exopolysaccharide (EPS) from lactic acid bacteria (LAB) has been developed as a potential biopolymer. A few studies have investigated the EPS produced by marine LAB. This study reports the wound healing activity of an EPS produced by a marine isolate identified as Lactiplantibacillus plantarum EI6, in addition to assessing L. plantarum EI6's probiotic properties. EI6 demonstrated promising antimicrobial activity against different pathogenic bacteria, as well as the ability to withstand stomach pH 3, tolerate 0.3% bile salt concentration, and exhibit no signs of hemolysis. Furthermore, EI6 was able to produce 270 mg/L of EPS upon growth for 48 h at 37°C in an MRS medium enriched with 1.0% of sucrose. The chemical features of the novel EI6-EPS were investigated: the UV-vis estimated a high carbohydrate content of ~91.5%, and the FTIR emphasized its polysaccharide nature by the characteristic hydroxyl, amide I, II, & III, and glycosidic linkage regions. The GC-MS and NMR analyses revealed the existence of five monosaccharides, namely, rhamnose, galactose, mannose, glucose, and arabinose, existing mainly in the pyranose form and linked together by α- and β-glycosidic linkages. EI6-EPS was found to be safe (IC50 > 100 μg/ml) and induced human skin fibroblasts (HSF) proliferation and migration. These findings imply that EI6 can be used as a safe source of bioactive polymer in wound care.

Upcycling agro-industrial blueberry waste into platform chemicals and structured materials for application in marine environments

Blueberry pruning waste (BPw), sourced as residues from agroforestry operations in Chile, was used to produce added-value products, including platform chemicals and materials. BPw fractionation was implemented using biobased solvents (γ-valerolactone, GVL) and pyrolysis (500 °C), yielding solid fractions that are rich in phenols and antioxidants. The liquid fraction was found to be enriched in sugars, acids, and amides. Alongside, filaments and 3D-printed meshes were produced via wet spinning and Direct-Ink-Writing (DIW), respectively. For the latter purpose, BPw was dissolved in an ionic liquid, 1-ethyl-3-methylimidazolium acetate ([emim][OAc]), and regenerated into lignocellulose filaments with highly aligned nanofibrils (wide-angle X-ray scattering) that simultaneously showed extensibility (wet strain as high as 39%). BPw-derived lignocellulose filaments showed a tenacity (up to 2.3 cN dtex^-1) that is comparable to that of rayon fibers and showed low light reflectance (R _ES factor <3%). Meanwhile, DIW of the respective gels led to meshes with up to 60% wet stretchability. The LCF and meshes were demonstrated to have reliable performance in marine environments. As a demonstration, we show the prospects of replacing plastic cords and other materials used to restore coral reefs on the coast of Mexico.

Algal Polysaccharides-Based Hydrogels: Extraction, Synthesis, Characterization, and Applications

Hydrogels are three-dimensional crosslinked hydrophilic polymer networks with great potential in drug delivery, tissue engineering, wound dressing, agrochemicals application, food packaging, and cosmetics. However, conventional synthetic polymer hydrogels may be hazardous and have poor biocompatibility and biodegradability. Algal polysaccharides are abundant natural products with biocompatible and biodegradable properties. Polysaccharides and their derivatives also possess unique features such as physicochemical properties, hydrophilicity, mechanical strength, and tunable functionality. As such, algal polysaccharides have been widely exploited as building blocks in the fabrication of polysaccharide-based hydrogels through physical and/or chemical crosslinking. In this review, we discuss the extraction and characterization of polysaccharides derived from algae. This review focuses on recent advances in synthesis and applications of algal polysaccharides-based hydrogels. Additionally, we discuss the techno-economic analyses of chitosan and acrylic acid-based hydrogels, drawing attention to the importance of such analyses for hydrogels. Finally, the future prospects of algal polysaccharides-based hydrogels are outlined.