Pectic Polysaccharides Research Articles

Pectic polysaccharides modulate colloidal stability and astringency perception of bottle aged Cabernet Sauvignon wines

Anthocyanins, tannins, and polymeric pigments, which are formed during red wine aging, are arguably the most important phenolic constituents of red wine, because they provide color, color stability, and mouthfeel properties like astringency. The extraction of polyphenols is accompanied with the extraction of grape-derived pectic polysaccharides leading to interactions between the two compound classes during fermentation and wine aging affecting tannin and pigment precipitability. Thereby, the implications for red wine quality are dependent on the structural features of the polysaccharides. In this study, polyphenolic and pectic polysaccharide composition of commercially available Cabernet Sauvignon wines, which were subjected to forced aging, were characterized to investigate the effect of red wine aging on the interactions between polysaccharides and polyphenols. This was accomplished by removing polysaccharides from the wines and comparing the polyphenolic composition of the wines and the reconstituted polysaccharide-free wines. Descriptive sensory analysis including “overall astringency”, “unripe” and “dry” was conducted on all samples to examine the implications of polysaccharide-polyphenol interactions on the astringency perception of red wines. The analyzed wines can be classified into two groups based on their colloidal stability, whereby large, neutral, and highly esterified polysaccharides promoted tannin and pigment protein precipitability and impaired the age-related formation of pigmented tannins. Small, acidic, and polar pectin fragments show a preventive effect on the precipitation of polyphenols. Sensory analysis revealed that the perception of the astringency sub-qualities “unripe” and “dry” are related to the interactions between pectic polysaccharides and polyphenols. Depending on the polysaccharide composition, the astringency of the wines increased or decreased during aging.

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.

Structural characterization of three acidic polysaccharides from Opuntia dillenii Haw. fruits and their protective effect against hydrogen peroxide-induced oxidative stress in Huh-7 cells

Three novel acidic polysaccharide fractions (OFPP-1, OFPP-2, OFPP-3) with different molecular weights (803.7, 555.1 and 414.5 kDa) were isolated from the peeled Opuntia dillenii Haw. fruits by alkali-extraction, graded alcohol precipitation and column chromatography. Structural analysis indicated that OFPPs were pectic polysaccharides consisting of rhamnose, arabinose and galactose residues. The backbone of OFPP-1 consisted of a repeating unit →6-α-D-GalpA-(1→2)-α-L-Rhap-(1→ with T-α-D-GalpA-(1→6)-α-D-GalpA-(1→4)-α-D-Glcp-(1→, T-β-D-Xylp-(1→6)-α-D-GalpA-(1→4)-α-D-Glcp-(1→ or T-α-D-GalpA-(1→3)-α-L-Araf-(1→ as the side chains. The backbone of OFPP-2 consisted of a disaccharide repeating unit →2)-α-L-Rhap-(1→4)-β-D-GalpA-(1→ with T-β-L-Araf-(1→ as the branches substituted at the O-4 position of →2,4)-α-L-Rhap-(1→. Whereas the backbone of OFPP-3 was →2,4)-α-L-Rhap-(1→2)-α-L-Rhap-(1→3)-β-L-Araf-(1→ or →2,4)-α-L-Rhap-(1→2)-α-L-Rhap-(1→4)-β-D-GalpA-(1→, which was branched at the O-4 position of →2,4)-α-L-Rhap-(1→. Moreover, these 3 polysaccharide fractions could protect Huh-7 cells against H2O2-induced oxidative stress to different extents by decreasing the MDA content and increasing the SOD, CAT, GSH-Px activities and the GSH level in the Huh-7 cells. These results suggest that OFPPs have the potential to be used as natural antioxidants.

Structural properties and biological effects of pectic polysaccharides extracted from Tartary buckwheat sprouts by high pressure-assisted deep eutectic solvent extraction

Tartary buckwheat sprout is commonly consumed as salads and healthy vegetables, which is rich in pectic polysaccharides. Nevertheless, the knowledge about pectic polysaccharides extracted from Tartary buckwheat sprouts (TBSP) are still limited. To facilitate the potential applications of TBSP as fortified ingredients or healthy foods, the impacts of conventional hot water extraction (CHW), deep eutectic solvent (DES)-assisted extraction (DEE), and high pressure-assisted DES extraction (HPDEE) on their structural and biological properties were evaluated. Compared with the CHW method, our findings revealed that both DEE and HPDEE methods could obviously promoted the yields of TBSP and regulated their structural properties, resulting in the improvement of their biological functions. Especially, the HPDEE method could obviously decreased the molecular mass, apparent viscosity, and esterification degree of TBSP, while notably increased the uronic acids and bound flavonoids. Indeed, the HPDEE method could remarkedly enhance the antioxidant, anti-glycosylation, and immunostimulatory activities of TBSP probably via reducing its molecular mass and degree of esterification, and increasing its free uronic acids and bound flavonoids. These findings reveal that the HPDEE method has good potentials for selectively extracting distinctive TBSP with superior biological functions.

Preparation, physicochemical and functional characterization of pectic polysaccharides from fresh passion fruit peel by magnetic-induced electric field-assisted three-phase partitioning

In this study, we explored the use of magnetic-induced electric field (MIEF) treatment at various excitation voltages to assist three-phase partitioning (TPP) methods in extracting and separating pectic polysaccharides (PFPs) from the peel of fresh passion fruit (Passiflora edulis f. flavicarpa). The findings indicated that applying MIEF treatment prior to TPP separation significantly reduced the total sugar and galacturonic acid contents, as well as the degree of esterification of PFPs, with increasing excitation voltage. This treatment notably enhanced their yields and molecular weights. Although the MIEF treatment did not alter the monosaccharide composition of PFPs, it significantly modified their molar ratios of monosaccharides, thereby altering the backbone structure and neutral sugar side chains, which resulted in varied microstructures. Furthermore, especially at higher excitation voltages (≥300 V), the MIEF treatment improved the thermal stability, rheological, and emulsifying properties of PFPs. Consequently, our data suggest that the MIEF-assisted TPP method is a promising approach for the efficient and environmentally friendly preparation of pectic polysaccharides from plant materials.

Preparation, characterization, and prebiotic potential of pectic oligosaccharide enzymatically derived from citric acid-extracted pumpkin pectic polysaccharide

Pectic polysaccharide from pumpkin pulp was enzymolyzed with Pectinex® Ultra SP-L. Afterward, the enzymolyzed pectic polysaccharide was fractionated into four fractions (Fraction 1, Fraction 2, Fraction 3, and Fraction 4) using dialysis tubes to elucidate the structural and physicochemical properties of pumpkin pectic oligosaccharide (PkPOS) with the most effective prebiotic potential. From the molecular weight (Mw) analysis, Fraction 1, Fraction 2, and Fraction 3 were classified as PkPOS (Mw of 1.47–4.09 kDa) and Fraction 4 as modified pectin (Mw mainly of 5.63–41.94 kDa). Combining the analysis results, a possible structure of each fraction was proposed as follows: Fraction 1 consisted mainly of galacturonic acid (GalA, 95.77%), most of which were presumably the reducing terminal α-GalA residues. Fraction 2, Fraction 3, and Fraction 4 consisted of the α-1,4-linked GalA residues and (substituted and/or unsubstituted) α-1,2-linked rhamnose (Rha) residues, indicating the presence of both the homogalacturonan and rhamnogalacturonan-I (RG-I) regions in their molecular structure. The proportion of the RG-I region was in descending order of Fraction 4 (GalA/Rha of 4.25) > Fraction 3 (GalA/Rha of 8.83) > Fraction 2 (GalA/Rha of 11.70). Among four fractions and fructooligosaccharides (FOS), Fraction 2 exhibited excellent stimulating effects on the growth of Lb. acidophilus, Lcb. rhamnosus GG, Lcb. casei, and Lcb. paracasei. Generally, Fraction 2 was the most effective in promoting the production of acetate. Although well-designed in vivo studies on prebiotic activities are needed, the present study suggests that Fraction 2 can be considered a promising candidate for a new generation of prebiotics.

Extraction, characterization and intestinal anti-inflammatory and anti-oxidative activities of polysaccharide from stems and leaves of Chuanminshen violaceum M. L. Sheh & R. H. Shan

Ethnopharmacological relevanceChuanminshen violaceum M. L. Sheh & R. H. Shan (CV) is used as a medicine with roots, which have the effects of benefiting the lungs, harmonizing the stomach, resolving phlegm and detoxifying. Polysaccharide is one of its main active components and has various pharmacological activities, but the structural characterization and pharmacological activities of polysaccharide from the stems and leaves parts of CV are still unclear. Aim of the studyThe aim of this study was to investigate the optimal extraction conditions for ultrasound-assisted extraction of polysaccharide from CV stems and leaves, and to carry out preliminary structural analyses, anti-inflammatory and antioxidant effects of the obtained polysaccharide and to elucidate the underlying mechanisms. Materials and methodsThe ultrasonic-assisted extraction of CV stems and leaves polysaccharides was carried out, and the response surface methodology (RSM) was used to optimize the extraction process to obtain CV polysaccharides (CVP) under the optimal conditions. Subsequently, we isolated and purified CVP to obtain the homogeneous polysaccharide CVP-AP-I, and evaluated the composition, molecular weight, and structural features of CVP-AP-I using a variety of technical methods. Finally, we tested the pharmacological activity of CVP-AP-Ⅰ in an LPS-induced model of oxidative stress and inflammation in intestinal porcine epithelial cells (IPEC-J2) and explored its possible mechanism of action. ResultsThe crude polysaccharide was obtained under optimal extraction conditions and subsequently isolated and purified to obtain CVP-AP-Ⅰ (35.34 kDa), and the structural characterization indicated that CVP-AP-Ⅰ was mainly composed of galactose, galactose, rhamnose and glucose, which was a typical pectic polysaccharide. In addition, CVP-AP-Ⅰ attenuates LPS-induced inflammation and oxidative stress by inhibiting the expression of pro-inflammatory factor genes and proteins and up-regulating the expression of antioxidant enzyme-related genes and proteins in IPEC-J2, by a mechanism related to the activation of the Nrf2/Keap1 signaling pathway. ConclusionThe results of this study suggest that the polysaccharide isolated from CV stems and leaves was a pectic polysaccharide with similar pharmacological activities as CV roots, exhibiting strong anti-inflammatory and antioxidant activities, suggesting that CV stems and leaves could possess the same traditional efficacy as CV roots, which is expected to be used in the treatment of intestinal diseases.

Intestinal lymphatic transport of Smilax china L. pectic polysaccharide via Peyer's patches and its uptake and transport mechanisms in mononuclear phagocytes

Recently, the intestinal lymphatic transport based on Peyer's patches (PPs) is emerging as a promising absorption pathway for natural polysaccharides. Herein, the aim of this study is to investigate the PP-based oral absorption of a pectic polysaccharide from Smilax china L. (SCLP), as well as its uptake and transport mechanisms in related immune cells. Taking advantages of the traceability of fluorescently labeled SCLP, we confirmed that SCLP could be absorbed into PPs and captured by their mononuclear phagocytes (dendritic cells and macrophages) following oral administration. Subsequently, the systematic in vitro study suggested that the endocytic mechanisms of SCLP by model mononuclear phagocytes (BMDCs and RAW264.7 cells) mainly involved caveolae-mediated endocytosis, macropinocytosis and phagocytosis. More importantly, SCLP directly binds and interacts with toll-like receptor 2 (TLR2) and galectin 3 (Gal-3) receptor, and was taken up by mononuclear phagocytes in receptor-mediated manner. After internalization, SCLP was intracellularly transported primarily through endolysosomal pathway and ultimately localized in lysosomes. In summary, this work reveals novel information and perspectives about the in vivo fate of SCLP, which will contribute to further research and utilization of SCLP and other pectic polysaccharides.

Structural characterization and prebiotic activity of rhamnogalacturonan-I rich pumpkin pectic polysaccharide extracted by alkaline solution

The present study aimed to investigate the structural and physicochemical characteristics of alkali-extracted pectic polysaccharide (AkPP) and to evaluate its prebiotic effects. AkPP was obtained from pumpkin pulp using an alkaline extraction method. AkPP, which had a molecular weight (Mw) of mainly 13.67 kDa and an esterification degree of 9.60%, was composed mainly of galacturonic acid (GalA), rhamnose (Rha), galactose, and arabinose. The ratio of the homogalacturonan (HG) region to the rhamnogalacturonan-I (RG-I) region in AkPP was 48.74:43.62. In the nuclear magnetic resonance spectrum, the signals indicating α-1,4-linked D-GalA, α-1,2-linked L-Rha, α-1,2,4-linked L-Rha residues were well resolved, demonstrating the presence of the HG and RG-I regions in its molecular structure. Collectively, AkPP was low methoxyl pectin rich in the RG-I region with short side chains and had a low Mw. Thermal analysis revealed that AkPP had good thermal stability. Compared to inulin, AkPP more effectively promoted the proliferation of Lactobacillus acidophilus, Lacticaseibacillus rhamnosus GG, Lacticaseibacillus casei, and Lacticaseibacillus paracasei and the production of lactic, acetic, and propionic acids. This study presents the unique structural features of AkPP and provides a scientific basis for further investigation of the potential of AkPP as a promising prebiotic.

In vitro simulated digestion and fermentation characteristics of pectic polysaccharides from fresh passion fruit (Passiflora edulis f. flavicarpa L.) peel

In this study, two pectic polysaccharides (PFP-T and PFP-UM) were extracted from fresh passion fruit peels using three-phase partitioning (TPP) and sequential ultrasound-microwave-assisted TPP methods, respectively, and their effects on the in vitro gastrointestinal digestion and fecal fermentation characteristics were examined. The results indicate that gastrointestinal digestion has a minimal effect on the physicochemical and structural characteristics of PFP-T and PFP-UM. However, during in vitro fecal fermentation, both undigested PFP-T and PFP-UM are significantly degraded and utilized by intestinal microorganisms, showing increased the total relative abundance of Firmicutes and Bacteroidota in the intestinal flora. Notably, compared with PFP-UM, PFP-T better promoted the reproduction of beneficial bacteria such as Prevotella, Megasphaera and Dialister, while suppressed the growth of harmful genera including Escherichia-Shigella, producing higher content of short-chain fatty acids. Therefore, our findings suggest that PFP-T derived from passion fruit peel has potential as a dietary supplement for promoting intestinal health.

Industrial byproduct pine nut skin factorial design optimization for production of subcritical water extracts rich in pectic polysaccharides, xyloglucans, and phenolic compounds by microwave extraction

Pine nut skin (Pinus pinea L.) is a poorly explored industrial byproduct with potential to be utilized as a food ingredient. Subcritical water extraction (SWE), an eco-friendly extraction technique with higher efficiency than hot-water extraction (HWE), was studied to evaluate its suitability in producing extracts rich in soluble fiber and phenolic compounds. For this, a factorial design was developed considering temperature (120–180 °C), time (2–10 min), and mass/volume ratio (1–3 g/60 mL) under microwave irradiation. This design aimed to maximize the extraction of carbohydrates, while achieving the highest content of phenolic compounds and antioxidant activity. SWE produced higher yields (2.6-fold in relation to HWE) of extracts rich in polysaccharides, determined by methylation analysis, oligosaccharides, determined by GC-qMS as alditol acetates, and phenolic compounds, determined by HPLC-ESI-MS. SWE increased the recovery of pectic oligosaccharides (10-fold) and xyloglucans (2-fold), and allowed to recover pectic polysaccharides, type II arabinogalactans and insoluble-bound phenolic compounds. Mono-, oligo- and polysaccharides were not hydrolyzed during in vitro gastrointestinal digestion, showing potential prebiotic functionality. Although phenolic compounds suffered a 23 % (gallic acid equivalents) decrease, phenolic acids and aldehydes were released or conserved upon intestinal phase. These results highlight the potential of PNS valorization as functional food ingredients through the subcritical water solubilization of polysaccharides and phenolic compounds.

Structural analysis and in vitro fermentation characteristics of an Avicennia marina fruit RG-I pectin as a potential prebiotic

Avicennia marina (Forssk.) Vierh. is a highly salt-tolerant mangrove, and its fruit has been traditionally used for treating constipation and dysentery. In this study, a pectin (AMFPs-0-1) was extracted and isolated from this fruit for the first time, its structure was analyzed, and the effects on the human gut microbiota were investigated. The results indicated that AMFPs-0-1 with a molecular weight of 798 kDa had a backbone consisting of alternating →2)-α-L-Rhap-(1→ and →4)-α-D-GalpA-(1→ residues and side chains composed of →3-α-L-Araf-(1→-linked arabinan with a terminal β-L-Araf, →5-α-L-Araf-(1→-linked arabinan, and →4)-β-D-Galp-(1→-linked galactan that linked to the C-4 positions of all α-L-Rhap residues in the backbone. It belongs to a type I rhamnogalacturonan (RG-I) pectin but has no arabinogalactosyl chains. AMFPs-0-1 could be consumed by human gut microbiota and increase the abundance of some beneficial bacteria, such as Bifidobacterium, Mitsuokella, and Megasphaera, which could help fight digestive disorders. These findings provide a structural basis for the potential application of A. marina fruit RG-I pectic polysaccharides in improving human intestinal health.

Pectin forms polymeric pigments by complexing anthocyanins during red winemaking and ageing

The long-term stability of red wine color depends on the formation of polymeric pigments from anthocyanins. Although there is still a lot of uncertainty about the specific structure of this diverse group of pigments, there is consensus that they are reaction products of anthocyanins and other polyphenols. Interactions between anthocyanins and pectic polysaccharides have been suggested to stabilize anthocyanins. This study explores the impact of such interactions by adding pectin during red winemaking.The results demonstrate that these interactions induce the formation of additional polymeric pigments which enhance the pigment stability during fermentation and aging. While initial pigment formation is higher in wines with added pectin, a notable proportion of the complexes degrades in the later stages of fermentation. Presumably, tannins form insoluble complexes with pectin, reducing tannin concentration by more than 300 mg/L. Anthocyanin concentrations decrease by over 400 mg/L, and polymeric pigments double.Anthocyanins that form polymeric pigments with pectic polysaccharides expand the range of pigments in red wines with possible consequences for the sensory properties of the wine. These findings highlight the complex interactions between pectin, anthocyanins, and tannins, and their influence on pigment formation and wine composition during fermentation and aging.

Impacts of ultrasound-assisted Fenton degradation and alkaline de-esterification on structural properties and biological effects of pectic polysaccharides from Tartary buckwheat leaves

Tartary buckwheat (Fagopyrum tataricum (L.) Gaertn) leaf has abundant rhamnogalacturonan-I enriched pectic polysaccharides, which exert various health-promoting effects. Nevertheless, the potential relationship between the chemical structure and the biological function of pectic polysaccharides from Tartary buckwheat leaves (TBP) remains unclear. Therefore, to bridge the gap between the chemical structure and the biological function of TBP, the impacts of ultrasound-assisted Fenton degradation (UFD) and mild alkaline de-esterification (MAD) on structural properties and biological effects of TBP were systematically studied. Compared with the native TBP (molecular mass, 9.537 × 104 Da), the molecular masses of degraded TBPs (TBP-MMW, 4.811 × 104 Da; TBP-LMW, 2.101 × 104 Da) were significantly reduced by the UFD modification, while their primary chemical structures were overall stable. Besides, compared with the native TBP (esterification degree, 22.73 %), the esterification degrees of de-esterified TBPs (TBP-MDE, 14.27 %; TBP-LDE, 6.59 %) were notably reduced by the MAD modification, while their primary chemical structures were also overall stable. Furthermore, the results revealed that both UFD and MAD modifications could significantly improve the antioxidant, antiglycation, and immunostimulatory effects of TBP. Indeed, TBP’s biological effects were negatively correlated to its molecular mass and esterification degree, while positively linked to its free uronic acids. The findings demonstrate that both UFD and MAD modifications are promising techniques for the structural modification of TBP, which can remarkedly promote its biological effects. Besides, the present results are conducive to better understanding TBP’s structure-bioactivity relationship.

Ultrasonic-assisted extraction of polysaccharide from Paeoniae Radix alba: Extraction optimization, structural characterization and antioxidant mechanism in vitro

Paeoniae Radix alba is used in Traditional Chinese Medicine for the treatment of gastrointestinal disorders, immunomodulatory, cancer, and other diseases. In the current study, the yield of Paeoniae Radix alba polysaccharide (PRP) was significantly increased with optimal ultrasound-assisted extraction compared to hot water extraction. Further, an acidic polysaccharide (PRP-AP) was isolated from PRP after chromatographic separation and was characterized as a typical pectic polysaccharide with side chains of arabinogalactans types I and II. Moreover, it showed antioxidant effects on LPS-induced damage on IPEC-J2 cells determined by qRT-PCR and ELISA, including decreasing the pro-inflammatory factors' expressions and increasing the antioxidant enzymes activities, which was shown to be related to the Nrf2/Keap1 pathway modulated by PRP-AP. The metabolites change (such as itaconate, cholesterol sulfate, etc.) detected by untargeted metabolomic analysis in cells was also shown to be modulated by PRP-AP, and these metabolites were further utilized and protected cells damaged by LPS. These results revealed the cellular active mechanism of the macromolecular PRP-AP on protecting cells, and supported the hypothesis that PRP-AP has strong benefits as an alternative dietary supplement for the prevention of intestinal oxidative stress by modulating cellular metabolism.

Potential structure–function relationships of pectic polysaccharides from quinoa microgreens: Impact of various esterification degrees

Pectic polysaccharides are one of the most vital functional ingredients in quinoa microgreens, which exhibit numerous health-promoting benefits. Nevertheless, the detailed information about the structure–function relationships of pectic polysaccharides from quinoa microgreens (QMP) remains unknown, thereby largely restricting their applications as functional foods or fortified ingredients. Therefore, to unveil the possible structure–function relationships of QMP, the mild alkali de-esterification was utilized to modify QMP, and then the correlations of esterification degrees of native and modified QMPs to their biological functions were systematically investigated. The results showed that the modified QMPs with different esterification degrees were successfully prepared by the mild alkali treatment, and the primary chemical structure (e.g., compositional monosaccharides and glycosidic linkages) of the native QMP was overall stable after the de-esterified modification. Furthermore, the results revealed that the antioxidant capacity, antiglycation effect, prebiotic potential, and immunostimulatory activity of the native QMP were negatively correlated to its esterification degree. In addition, both native and modified QMPs exerted immunostimulatory effects through activating the TLR4/NF-κB signaling pathway. These results are conducive to unveiling the precise structure–function relationships of QMP, and can also promote its applications as functional foods or fortified ingredients.

Antioxidant and flexible bioplastics based on microwave-assisted extracted coffee fruit cascara pectic polysaccharides

Pectic polysaccharides with film-forming ability are often recovered from renewable agrifood by-products through solid-liquid extraction (SLE). Targeting an organic solvent-free approach, in this work, it is hypothesized that pectic polysaccharides of interest for bioplastics development can be recovered by microwave-assisted extraction (MAE) and purified by ultrafiltration. Coffee fruit cascara (CFC) was used as raw material. MAE of CFC-derived pectic polysaccharides was carried out at 120 °C at different times (2 min, 5 min, and 10 min). A 3-times (1 h each) sequential SLE with 2% acetic acid under reflux at atmospheric pressure was also performed. High molecular weight (HMW) extracts obtained by MAE for 2 min (HMW_MAE 2′) and by SLE for 1 h (HMW_SLE1), composed of 60 mol% and 54 mol% uronic acids with 18% and 17% methyl-esterification, and 7% and 8% acetylation, respectively, were selected for bioplastics development. HMW_MAE 2’ originated slightly transparent, dark brown, hydrophilic (ca. 32° water contact angle), and antioxidant (90% ABTS•+ inhibition after 5 min) bioplastics, similar to HMW_SLE1-derived materials, but 10-fold more stretchable (20% and 2% elongation at break, respectively). Therefore, MAE followed by ultrafiltration showed to be a fast and clean strategy to recover low methyl-esterified CFC pectic polysaccharides with the ability to develop antioxidant and flexible bioplastics.

Physicochemical Characterization, Antioxidant and Anticancer Activity Evaluation of an Acidic Polysaccharide from Alpinia officinarum Hance.

AHP-3a, a triple-helix acidic polysaccharide isolated from Alpinia officinarum Hance, was evaluated for its anticancer and antioxidant activities. The physicochemical properties and structure of AHP-3a were investigated through gel permeation chromatography, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy. The weight-average molecular weight of AHP-3a was 484 kDa, with the molar percentages of GalA, Gal, Ara, Xyl, Rha, Glc, GlcA, and Fuc being 35.4%, 21.4%, 16.9%, 11.8%, 8.9%, 3.1%, 2.0%, and 0.5%, respectively. Based on the results of the monosaccharide composition analysis, methylation analysis, and NMR spectroscopy, the main chain of AHP-3a was presumed to consist of (1→4)-α-D-GalpA and (1→2)-α-L-Rhap residues, which is a pectic polysaccharide with homogalacturonan (HG) and rhamnogalacturonan-I (RG-I) structural domains containing side chains. In addition, the results of the antioxidant activity assay revealed that the ability of AHP-3a to scavenge DPPH, ABTS, and OH free radicals increased with an increase in its concentration. Moreover, according to the results from the EdU, wound healing, and Transwell assays, AHP-3a can control the proliferation, migration, and invasion of HepG2 and Huh7 hepatocellular carcinoma cells without causing any damage to healthy cells. Thus, AHP-3a may be a natural antioxidant and anticancer component.

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.

Simultaneously efficient dissolution and structural modification of chrysanthemum pectin: Targeting at proliferation of Bacteroides

Pectic polysaccharide is a bioactive ingredient in Chrysanthemum morifolium Ramat. ‘Hangbaiju’ (CMH), but the high proportion of HG domain limited its use as a prebiotic. In this study, hot water, cellulase-assisted, medium-temperature alkali, and deep eutectic solvent extraction strategies were firstly used to extract pectin from CMH (CMHP). CMHP obtained by cellulase-assisted extraction had high purity and strong ability to promote the proliferation of Bacteroides and mixed probiotics. However, 4 extraction strategies led to general high proportion of HG domain in CMHPs. To further enhance the dissolution and prebiotic potential of CMHP, pectinase was used alone and combined with cellulase. The key factor for the optimal extraction was enzymolysis by cellulase and pectinase in a mass ratio of 3:1 at 1 % (w/w) dosage. The optimal CMHP had high yield (15.15 %), high content of total sugar, and Bacteroides proliferative activity superior to inulin, which was probably due to the cooperation of complex enzyme on the destruction of cell wall and pectin structural modification for raised RG-I domain (80.30 %) with relatively high degree of branching and moderate HG domain. This study provided a green strategy for extraction of RG-I enriched prebiotic pectin from plants.