Structural studies of biologically active pectin-containing polysaccharides of pomegranate Punica granatum

Optimization and Validation of Arabinoxylan Quantification in Gluten-Free Cereals via HPAEC-PAD Based on Design of Experiments

Arabinoxylans (AXs) are dietary fibers in monocotyledon cell walls that benefit digestive health and enhance food functionality. Despite their importance, no standardized method exists for AX quantification in gluten-free (GF) cereals. This study investigated the effect of hydrolysis parameters for AX quantification in GF cereals (maize, rice, oat) with varying AX content and nutritional profiles to address matrix effects. The effects of trifluoroacetic acid (TFA) concentration (0.25-4 M), temperature (90-127 °C), and time (1-5 h) on hydrolysis efficiency were examined, whereby temperature showed, in contrast to acid concentration and time, a pronounced influence. The design of experiment (DoE) model predicted 2 M TFA, 2.4 h, and 103 °C as the optimal conditions for maximizing AX yield without detectable monosaccharide decomposition for all varieties. This was experimentally confirmed with a deviation of less than 10%. An extensive validation confirmed the method's accuracy and reliability for this unified method.

The interaction between Angelica sinensis polysaccharide ASP-2pb and specific gut bacteria alleviates rheumatoid arthritis in rats

Angelica sinensis polysaccharide (ASP) alleviated Rheumatoid arthritis (RA), but whether the relief was attributed to ASP itself or its microbial metabolites remained unclear. We characterized the main fraction of ASP (ASP-2pb) as a polysaccharide with molecular weight of 92.02 kDa. It contained approximately 48 repeating units of →6)-β-D-Galp-(1 → 3)-4-OMe-β-D-Galp-(1 → 4)-α-D-GalpA-(1 → 6)-β-D-Galp-(1 → 3)-4-OMe-β-D-Galp-(1→3)-β-D-Galp-(1 → 3)-β-D-Galp-(1 → 3)-β-D-Galp-(1 → with branches of Araf and Galp. Using ASP-2pb as intervention, the symptoms of RA in rats including joint swelling and inflammation were alleviated. Pseudo-germ-free animal test confirmed the necessity of specific gut bacteria during this alleviation. Bacteria such as Candidatus_Saccharimonas, Lactobacillus, Bifidobacterium, Faecalibaculum, Parvibacter, Ruminococcus_torques_group, Fournierella and Alloprevotella ought to be the key bacteria. Metabolites generated by these gut bacteria such as myristoleic acid, cuminaldehyde, 4-deoxypyridoxine and galactosylhydroxylysine, should be the key to RA remission. Therefore, specific metabolites were the consequence of the interaction between ASP-2pb and specific intestinal bacteria, and were responsible for the RA improvement.

Structural Characteristics, Gelling Properties, In Vitro Antioxidant Activity and Immunomodulatory Effects of Rhamnogalacturonan-I Rich Pectic Polysaccharides Alkaline-Extracted from Wax Apple (Syzygium samarangense)

To upgrade the utilization of Syzygium samarangense in food industries, the key biological component, i.e., polysaccharide, was extracted from the fruit by alkaline treatment, and its structural characteristics, physicochemical properties, gelling properties and biological activities were investigated. The findings demonstrated that the alkaline-extracted S. samarangense polysaccharide (SSP-AK) predominantly exists as a pectic polysaccharide with a high rhamnogalacturonan-I domain. The monosaccharide composition primarily includes rhamnose, glucuronic acid, galacturonic acid, glucose, galactose, and arabinose. The molecular weight distribution of SSP-AK was characterized by two peaks, with fraction 1 exhibiting a high molecular weight of 7658 kDa and fraction 2 exhibiting a molecular weight of 345.3 kDa. Meanwhile, SSP-AK exhibited excellent rheological behavior and gelling properties upon Ca2+-induced gelation, which may be related to its relatively low degree of esterification of 41.3%. Further studies revealed that higher concentrations of pectin and Ca2+ led to the formation of stronger gels. The SSP-AK gels exhibited superior rheological properties, increased hardness, enhanced water-holding capacity, and a more compact network structure than the other gels. Moreover, SSP-AK exhibited significant in vitro antioxidant activity and immunomodulatory effects, including significantly enhancing the DPPH and ABTS radical-scavenging abilities and production of NO, IL-6, and TNF-α in RAW264.7 cell models. This study enhances the understanding of S. samarangense cell wall polysaccharides and may facilitate their application in the development of functional and health-oriented food products.

Structural insights and therapeutic potential of plant-based pectin as novel therapeutic for type 2 diabetes mellitus: A review

Type 2 diabetes mellitus (T2DM) is a global health challenge with limited efficacy of current treatments, necessitating alternative therapies. Plant-derived pectin, composed of galacturonic acid and structural domains such as homogalacturonan, has shown promise as an anti-diabetic agent. Pectin exerts its therapeutic effects through multiple mechanisms, including enhancing β-cell function, regulating glucose metabolism, improving insulin sensitivity, inhibiting digestive enzymes, and restoring gut microbiota balance. Its bioactivity is influenced by physicochemical properties like molecular weight, degree of methylation, and structural complexity. This review explores the anti-diabetic potential of pectin, its structure-activity relationships, and mechanisms of action, providing insights for its development as a novel therapeutic agent in T2DM management.

In vitro fermentation characteristics and modulation effects of polysaccharide fractions from Schisandra sphenanthera on intestinal microflora

Schisandra Sphenanthera polysaccharides fractions (SSPs), namely SSP40, SSP60, and SSP80, were obtained by gradient precipitation with 40 %, 60 %, and 80 % (v/v) ethanol, respectively. It was found that gradient ethanol precipitation (GEP) significantly affected the physicochemical and structural characteristics of SSPs, including molecular weight, monosaccharide composition, and surface morphology. Compared to fractions SSP40 and SSP60, SSP80 was observed to have a lower molecular weight (22.58 kDa) and certain specific monosaccharide composition, such as lower glucose content and higher galactose, arabinose, rhamnose, and galacturonic acid content. Furthermore, the apparent porosity of the SSPs increased with increasing ethanol concentration in GEP. After fermentation at 37 °C for 48 h, fraction SSP80 prominently promoted the production of more short-chain fatty acids (SCFAs), increasing from an initial 1.39 ± 0.08 to 26.75 ± 0.54 mmol/L. The SSP fraction types extracted by GEP greatly affected the modulation of the intestinal microflora at different levels. The SSP80 fraction with excellent structure demonstrated the best ability to modulate the intestinal microflora by increasing the relative abundance of Bacteroides, Faecalibacterium and Dialister and decreasing the relative abundance of Escherichia-Shigella. The remarkable differences in modulating the intestinal microflora confirmed the importance of carefully selecting GEP to fraction SSPs that promote health.

Unlocking soybean meal pectin recalcitrance using a multi-enzyme cocktail approach

Pectin is a complex plant heteropolysaccharide whose structure and function differ depending on its source. In animal feed, breaking down pectin is essential, as its presence increases feed viscosity and reduces nutrient absorption. Soybean meal, a protein-rich poultry feed ingredient, contains significant amounts of pectin, the structure of which remains unclear. Consequently, the enzyme activities required to degrade soybean meal pectin and how they interact are still open questions. In this study, we produced 15 recombinant fungal carbohydrate-active enzymes (CAZymes) identified from fungal secretomes acting on pectin. After observing that these enzymes were not active on soybean meal pectin when used alone, we developed a semi-miniaturized method to evaluate their effect as multi-activity cocktails. We designed and tested 12 enzyme pools, containing up to 15 different CAZymes, using several hydrolysis markers. Thanks to our multiactivity enzymatic approach combined with a Pearson correlation matrix, we identified 10 fungal CAZymes efficient on soybean meal pectin, 9 of which originate from Talaromyces versatilis. Based on enzyme specificity and linkage analysis, we propose a structural model for soybean meal pectin. Our findings underscore the importance of combining CAZymes to improve the degradation of agricultural co-products.

Immunomodulatory Acidic Polysaccharide from Jujube Fruit (Zizyphus jujuba Mill.): Insight into Their Chemical Characteristics and Modes of Action

Jujube (Zizyphus jujuba Mill.) has been consumed globally as a fruit and a nutraceutical food for millennia. This study presents the isolation and purification of a novel water-soluble polysaccharide fraction, ZJMP-2, from Z. jujuba Mill. ZJMP-2 underwent characterization through Fourier transform infrared (FT-IR), high-performance gel permeation chromatography-laser light scattering (HPGPC-LLS), gas chromatography-mass spectrometry (GC-MS), scanning electron microscopy (SEM), atomic force microscopy (AFM), and nuclear magnetic resonance (NMR) analyses. It consists of glucose, galactose, arabinose, rhamnose, and galacturonic acid in molar ratios of 0.41:0.08:0.11:0.05:0.33 and boasts an average molecular weight of approximately 57.8 kDa. Its backbone features the structure →2)-α-l-Rhap-(1 → 4)-α-d-GalpA-(1 → 4)-α-d-GalpA-6OMe-(1 → 4)-α-d-GalpA-(1 → 3, 4)-α-d-Glcp-(1 →, with branching at →5)-α-l-Araf-(1 →, →4)-β-d-Galp-(1 →, and →4)-α-d-Glcp-(1→ at position O-3 of →3, 4)-α-d-Glcp-(1 →. These structural variations contribute to the pronounced immunoregulatory effects of ZJMP-2. Specifically, ZJMP-2 significantly elevated the expression levels of TLR4, NF-κB, and TRAF6 proteins, enhancing RAW264.7 cell activity, index of splenic lymphocytes, and the production of cytokines and NO, thereby activating macrophages and promoting lymphocyte proliferation. In vivo studies demonstrated that ZJMP-2 promoted the heart, spleen, and bone marrow indices, peripheral blood and spleen cell counts, and the number of heart and bone marrow cells in mice. These findings demonstrated that ZJMP-2 has potential as an immunomodulator and provides valuable insights for developing natural immunomodulators in the pharmaceutical industry.

Structural identification, rheological properties and immunological receptor of a complex galacturonoglucan from fruits of Schisandra chinensis (Turcz.) Baill

A complex heteropolysaccharide SCP-2 named schisanan B (Mw = 1.005 × 105 g/mol) was obtained from water extracts of Schisandra chinensis fruits, and its planar structure was finally deduced as a galacturonoglucan by a combination of monosaccharide compositions, methylation analysis, partial acid hydrolysis, enzymatic hydrolysis and 1D/2D-nuclear magnetic resonance spectroscopy. The conformation of SCP-2 exhibited a globular shape with branching in ammonium formate aqueous solutions. The rheological properties of SCP-2 were investigated on concentrations, temperature, pH and salts. The in vitro immunomodulatory activity assay demonstrated that SCP-2 significantly enhanced the production of nitric oxide (NO) and stimulated the secretion of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) in macrophages. Through a combination of high-resolution live-cell imaging, surface plasmon resonance, and molecular docking techniques, SCP-2 exhibited a strong binding affinity with the Toll-like receptor 4 (TLR4). Moreover, western blot analysis revealed that SCP-2 effectively induced downstream signaling proteins associated with TLR4 activation, thereby promoting macrophage activation. The evidence strongly indicates that TLR4 functions as a membrane protein target in the activation of macrophages and immune regulation induced by SCP-2.

Valorization of citrus peel industrial wastes for facile extraction of extractives, pectin, and cellulose nanocrystals through ultrasonication: An in-depth investigation

In this work we developed an eco-friendly valorisation of Citrus wastes (CWs), through a solvent-assisted ultrasonication extraction technique, thus having access to a wide range of bio-active compounds and polysaccharides, extremely useful in different industrial sectors (food, cosmetics, nutraceutical). Water-based low-amplitude ultrasonication was examined as a potential method for pectin extraction as well as polar and non-polar citrus extractives (CEs), among which hesperidin and triglycerides of 18 carbon fatty acids were found to be the most representative ones. In addition, citric acid:glycerol (1:4)-based deep eutectic solvent (DES) in combination with ultrasonic extraction was utilized to extract microcellulose (CMC), from which stable cellulose nanocrystals (CNCs) with glycerol-assisted high amplitude ultrasonication were obtained. The physical and chemical properties of the extracted polysaccharides (pectin, micro and nanocellulose) were analysed through DLS, ζ-potential, XRD, HP-SEC, SEM, AFM, TGA-DSC, FTIR, NMR, and PMP-HPLC analyses. The putative structure of the extracted citrus pectin (CP) was analysed and elucidated through enzyme-assisted hydrolysis in correlation with ESI-MS and monosaccharide composition. The developed extraction methods are expected to influence the industrial process for the valorisation of CWs and implement the circular bio-economy.

Punica granatum L. polysaccharides: A review on extraction, structural characteristics and bioactivities

Punica granatum L., commonly known as pomegranate, is native to Afghanistan and Iran, and today widely cultivated all over the world. Pomegranate polysaccharides are one of the most important bioactive components of P. granatum, which have a wide range of beneficial biological activities, such as anticancer, immunostimulatory, hepatoprotection, anti-psoriasis and antioxidation. Hot water extraction is currently the most commonly used method to isolate pomegranate polysaccharides. The structural characteristics of pomegranate polysaccharides have been extensively investigated through various advanced modern analytical techniques. This review focuses on the extraction, purification, structural characteristics, biological activities and structure-activity relationships of polysaccharides from Punica granatum. The aim of this article is to comprehensively and systematically summarize recent information of polysaccharides from Punica granatum and to serve as a basis for further research and development as therapeutic agents and functional foods.

Structural characterization of polysaccharides from Panax ginseng C. A. Meyer root and their triggered potential immunoregulatory and radioprotective activities

With people's increasing awareness of healthy diet, the diverse health-promoting functions of ginseng have been widely recognized. As one of the key functional components, ginseng polysaccharides have attracted increasing research interest. Here, three purified polysaccharide fractions, GPS-1a, GPS-1b, and GPS-2, were obtained from the root extract of Panax ginseng C. A. Meyer. Structurally, GPS-1a and GPS-1b were both linked in a → 6)-α-D-Glcp-(1 → pattern but composed of glucose and galactose in molar ratios of 9.76:0.24 and 9.81:0.19. In contrast, GPS-2 was composed of glucose, galactose, arabinose, rhamnose, and galacturonic acid in a molar ratio of 1.82:1.94:0.79:0.52:4.93. The main backbone consisted of →4)-α-D-GalpA-(1→, →4)-α-D-GalpA-6OMe-(1→, →3, 4)-α-D-GalpA-(1→, →3)-α-L-Rhap-(1 → linages, and its branches are composed of →5)-α-L-Araf-(1→, →4)-β-D-Galp-(1→, →2)-β-D-Glcp-(1→, α-D-GalAp-(1→. Benefitting from this structural variance, GPS-2 exhibited the most significant immunoregulatory and radioprotective efficacies. Specifically, GPS-2 promoted TLR2, NF-κB, and TRAF6 protein expression levels, thereby significantly improving macrophage phagocytosis, splenic lymphocyte proliferation, and stimulation of NO, IL-1β, IL-6, and TNF-α secretion, which activated RAW264.7 and splenic lymphocytes. The following radioprotection activity tests unveiled that GPS-2 increased the organ index, number of peripheral blood cells, cellularity of splenocytes, and bone marrow cell numbers in irradiated mice. This investigation revealed the contribution of polysaccharide structure characteristics to the bioactive expression and elucidated the potential utilization of GPS-2 as a radioprotective agent or immunomodulator.

Structural clarification of mannoglucan GSBP-2 from Ganoderma sinense and its effects on triple-negative breast cancer migration and invasion

Ganoderma sinense, known as Lingzhi in China, is a medicinal fungus with anti-tumor properties. Herein, crude polysaccharides (GSB) extracted from G. sinense fruiting bodies were used to selectively inhibit triple-negative breast cancer (TNBC) cells. GSBP-2 was purified from GSB, with a molecular weight of 11.5 kDa and a composition of α-l-Fucp-(1→, β-d-Glcp-(1→, β-d-GlcpA-(1→, →3)-β-d-Glcp-(1→, →3)-β-d-GlcpA-(1→, →4)-α-d-Galp-(1→,→6)-β-d-Manp-(1→, and →3,6)-β-d-Glcp-(1→ at a ratio of 1.0:6.3:1.7:5.5:1.5:4.3:8.0:7.9. The anti-MDA-MB-231 cell activity of GSBP-2 was determined by methyl thiazolyl tetrazolium, colony formation, scratch wound healing, and transwell migration assays. The results showed that GSBP-2 could selectively inhibit the proliferation, migration, and invasion of MDA-MB-231 cells through the regulation of genes targeting epithelial-mesenchymal transition (i.e., Snail1, ZEB1, VIM, CDH1, CDH2, and MMP9) in the MDA-MB-231 cells. Furthermore, Western blotting results indicated that GSBP-2 could restrict epithelial-mesenchymal transition by increasing E-cadherin and decreasing N-cadherin expression through the PI3K/Akt pathway. GSBP-2 also suppressed the angiogenesis of human umbilical vein endothelial cells. In conclusion, GSBP-2 could inhibit the proliferation, migration, and invasion of MDA-MB-231 cells and showed significant anti-angiogenic ability. These findings indicate that GSBP-2 is a promising therapeutic adjuvant for TNBC.

Structural elucidation a complex galactosyl and glucosyl-rich pectin from the pericarp of immature fruits of Juglans mandshurica Maxim

A glucosyl-rich pectin, JMMP-3 (Mw, 2.572 × 104 g/mol, O-methyl % = 3.62%), was isolated and purified from the pericarp of the immature fruit of Juglans mandshurica Maxim. (QingLongYi). The structure of JMMP-3 was studied systematically by infrared spectroscopy, monosaccharide compositions, methylation analysis, partial acid hydrolysis, and 1/2D-NMR. The backbone of JMMP-3 possessed a smooth region (→ 4GalA1 →) and a hairy region (→ 4GalA1 → 2Rha1 →) with a molar ratio of 2: 5. The substitution of four characteristic side chains (R1-R4) occurs at C-4 of → 2,4)-α-Rhap-(1→, where R1 is composed of → 5)-α-Araf-(1→, R2 is composed of → 4)-β-Galp-(1 → and β-Galp-(1→, R3 is composed of α-Glcp-(1→, →4)-α-Glcp-(1 → and → 4,6)-α-Glcp-(1→, and R4 is composed of → 5)-α-Araf-(1→, β-Galp-(1→, → 4)-β-Galp-(1→, → 3,4)-β-Galp-(1→, → 4,6)-β-Galp-(1 → and → 2,4)-β-Galp-(1 → . In addition, the antitumor activity of JMMP-3 on HepG2 cells was preliminarily investigated.

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.

Antioxidant Active Polysaccharides Extracted with Oxalate from Wild Blackthorn Fruits (Prunus spinosa L.)

Although several therapeutic effects have been attributed to wild blackthorn fruits, their use is still negligible. Purification of the antioxidant-active fraction, obtained from wild blackthorn fruits by hot ammonium oxalate extraction (Ao), yielded seven fractions after successive elution with water, sodium chloride and sodium hydroxide solutions. The purified fractions differ in carbohydrates, proteins, and phenolics. About 60% of the applied Ao material was recovered from the column, with the highest yields eluted with 0.25 M NaCl solution, accounting for up to 70 wt% of all eluted material. Analyses have shown that two dominant fractions (3Fa and 3Fb) contain 72.8-81.1 wt% of galacturonic acids, indicating the prevalence of homogalacturonans (HG) with a low acetyl content and a high degree of esterification. The low content of rhamnose, arabinose and galactose residues in both fractions indicates the presence of RG-I associated with arabinogalactan. In terms of yield, the alkali-eluted fraction was also significant, as a dark brown-coloured material with a yield of ~15 wt% with the highest content of phenolic compounds of all fractions. However, it differs from other fractions in its powdery nature, which indicates a high content of salts that could not be removed by dialysis.

An acidic exopolysaccharide α-D-galacturono-β-D-glucan produced by the cyanobacterium Scytonema sp

Some cyanobacteria produce a wide range of secondary metabolites, some of which are of industrial interest. Exopolysaccharides, particularly interesting among them, represent relatively complex primary structures with interesting bioactivity, biodegradability and specific applications. Cultivation of the freshwater cyanobacterium Scytonema sp. provided a proteoglycan-type exopolysaccharide with a relatively low yield and a wide spectrum of molecular weights (Mw) ranging from 2.2 to 1313 × 103 g/mol. Chemical analyses detected the presence of carbohydrates (46 wt%), proteins (10 wt%) and uronic acids (8 wt%). Monosaccharide analysis revealed up to seven neutral sugars with a dominance of glucose (23.6 wt%), galactose (7.4 wt%) and fucose (5.0 wt%) residues, while the others had a much lower content (0.9-3.4 wt%). The presence of galacturonic acid (8.0 wt%) indicated the appearance of ionic type of exopolysaccharide. A preliminary structural study indicated that the α-D-galacturono-β-D-glucan forms a dominant part of Scytonema sp. exopolymer. Its backbone is composed of two 1,6-linked and one 1,2-linked β-D-Glcp residues, which is branched at O6 by side chains composed of α-D-GalAp(1 → 2)-β-D-Glcp(1→ dimer or monomeric β-D-Glcp(1→ residue.

Degradation of Angelica sinensis polysaccharide: Structures and protective activities against ethanol-induced acute liver injury

Angelica sinensis polysaccharide (ASP) possesses diverse bioactivities; however, its metabolic fate following oral administration remains poorly understood. To intuitively determine its intestinal digestion behavior after oral administration, ASP was labeled with fluorescein, and it was found to accumulate and be degraded in the cecum and colon. Therefore, we investigated the in vitro enzymatic degradation behavior and identified the products. The results showed that ASP could be degraded into fragments with molecular weights similar to those of the fragments observed in vivo. Structural characterization revealed that ASP is a highly branched acid heteropolysaccharide with AG type II domains, and its backbone is predominantly composed of 1,3-Galp, →3,6)-Galp-(1→6)-Galp-(1→, 1,4-Manp, 1,4-Rhap, 1,3-Glcp, 1,2,3,4-Galp, 1,3,4,6-Galp, 1,3,4-GalAp and 1,4-GlcAp, with branches of Araf, Glcp and Galp. In addition, the high molecular weight enzymatic degradation products (ASP H) maintained a backbone structure almost identical to that of ASP, but exhibited only partial branch changes. Then, the results of ethanol-induced acute liver injury experiments revealed that ASP and ASP H reduced the expression of aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), and malondialdehyde (MDA) and increased the superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) levels, thereby relieving ethanol-induced acute liver injury.

Structural characterization and osteogenic differentiation-promoting activity of polysaccharide purified from Chroogomphus rutilus

Chroogomphus rutilus (CR) possesses anti-inflammatory, antioxidant, and hypoglycemic properties. However, studies are yet to evaluate the anti-osteoporotic activity of the fungi and its polysaccharides. Therefore, this study is aimed at characterizing and evaluating the anti-osteoporotic effects of a novel polysaccharide from CR. The neutral polysaccharide CRP2 extracted and purified from the fruiting body of CR had a molecular weight of 20.41 kDa. Monosaccharide composition analysis revealed that CRP2 is composed of galactose, glucose, fucose, and mannose. The backbone of CRP2 primarily consisted of →6)-α-D-Galp-(1 → residues, with specific site substitutions speculated at partial positions, such as O-CH3 substitution at H-3 position, or a branch site located at C-2, including α-L-Fucp-(1 → 6)-β-D-Glcp-(1 → and α-D-Manp-(1→. CRP2 treatment increased trabecular bone density, restored a network-shaped structure, and upregulated the expression of osteoblast differentiation markers, including runt-related transcription factor 2, osterix, osteocalcin, and osteopontin in the femoral tissue of mice with osteoporosis (OP). Additionally, CRP2 treatment suppressed the expression of tumor necrosis factor-α and interleukin-1β in the femoral tissue of mice with OP. Mechanistically, CRP2 exerted anti-OP effect by inhibiting inflammation and promoting osteogenesis through the transforming growth factor β-1/Smad pathway. Conclusively, these findings augment our understanding of the potential role of CRP2 in OP treatment.

Structural elucidation of novel pro-inflammatory polysaccharides from Daphne mezereum L

Daphne mezereum L., an important medicinal plant in Scandinavian folk medicine, was used to treat ailments such as diarrhea, swelling and stomach pain. A range of natural compounds have been isolated, but little attention has been given to the polysaccharides in this plant. Previous work in our group have shown that a polysaccharide enriched fraction from the bark of D. mezereum exhibited pro-inflammatory effects. To pursue this further, the aim of the present work was to isolate and characterize these polysaccharides. From the ethanol-precipitate of a water extract, one neutral (DMP-NF) and one acidic (DMP-AF) fraction was isolated by anion-exchange chromatography. GC, GC-MS and 1D- and 2D-NMR were used to characterize the polysaccharide structures. DMP-NF appeared to be a mixture of arabinan, arabinogalactan and hemicelluloses such as xyloglucan, mannan and xylan. DMP-AF contained a pectic polysaccharide mainly consisting of an unusually long homogalacturonan backbone. Enzymatic treatment by pectinase of DMP-AF yielded DMP-ED, which contained a rhamnogalacturonan-I backbone with arabinan, galactan and arabinogalactan side chains. Both DMP-NF and DMP-ED induced IFN-γ and TNF-α secretion in peripheral blood mononuclear cells (PBMCs), DMP-ED being the most potent fraction. DMP-AF was less active, which might be due to a less sterically available rhamnogalacturonan-I domain.

An overview of microbial enzymatic approaches for pectin degradation

Pectin, a complex natural macromolecule present in primary cell walls, exhibits high structural diversity. Pectin is composed of a main chain, which contains a high amount of partly methyl-esterified galacturonic acid (GalA), and numerous types of side chains that contain almost 17 different monosaccharides and over 20 different linkages. Due to this peculiar structure, pectin exhibits special physicochemical properties and a variety of bioactivities. For example, pectin exhibits strong bioactivity only in a low molecular weight range. Many different degrading enzymes, including hydrolases, lyases and esterases, are needed to depolymerize pectin due to its structural complexity. Pectin degradation involves polygalacturonases/rhamnogalacturonases and pectate/pectin lyases, which attack the linkages in the backbone via hydrolytic and β-elimination modes, respectively. Pectin methyl/acetyl esterases involved in the de-esterification of pectin also play crucial roles. Many α-L-rhamnohydrolases, unsaturated rhamnogalacturonyl hydrolases, arabinanases and galactanases also contribute to heterogeneous pectin degradation. Although numerous microbial pectin-degrading enzymes have been described, the mechanisms involved in the coordinated degradation of pectin through these enzymes remain unclear. In recent years, the degradation of pectin by Bacteroides has received increasing attention, as Bacteroides species contain a unique genetic structure, polysaccharide utilization loci (PULs). The specific PULs of pectin degradation in Bacteroides species are a new field to study pectin metabolism in gut microbiota. This paper reviews the scientific information available on pectin structural characteristics, pectin-degrading enzymes, and PULs for the specific degradation of pectin.

Physicochemical, structural, and functional characterization of pectin extracted from quince and pomegranate peel: A comparative study

Pectin's physicochemical, structural, and functional characteristics vary widely depending on the source of extraction. In this study, pectins were extracted from seedless quince and pomegranate peel, and their physicochemical, structural, and functional properties were investigated. A Box-Behnken Design with three factors and three levels was applied to optimize the pectin extraction yield from each matrix. As a result, the best extraction yields for quince pectin (QP) and pomegranate peel pectin (PPP) were 11.44 and 12.08 % (w/w), respectively. Both extracted pectins exhibit a linear structure, with the homogalacturonan domain dominating the rhamnogalacturonan I. Both pectins are highly methyl-esterified (DM > 69 %) with a higher degree of acetylation for PPP than QP, with 12 and 8 %, respectively. Unlike QP, PPP has a narrow, homogenous distribution and greater molecular weight (120 kDa). Regarding functionality, 1 g of QP could retain 4.92 g of water, and both pectin emulsions were more stable at room temperature than at 4 °C. When the concentration of QP is increased, rheological measurements demonstrate that it exhibits pseudoplastic behavior. Finally, QP can be used as a thickener, whereas PPP can be utilized as starting material for chemical changes to create multifunctional pectins.

Research progress in extraction, purification, structure of fruit and vegetable polysaccharides and their interaction with anthocyanins/starch

Fruits and vegetables contain polysaccharides, polyphenols, antioxidant enzymes, and various vitamins, etc. Fruits and vegetables polysaccharides (FVPs), as an important functional factor in health food, have various biological activities such as lowering blood sugar, blood lipids, blood pressure, inhibiting tumors, and delaying aging, etc. In addition, FVPs exhibit good physicochemical properties including low toxicity, biodegradability, biocompatibility. Increasing research has confirmed that FVPs could enhance the stability and biological activities of anthocyanins, affecting their bioavailability to improve food quality. Simultaneously, the addition of FVPs in natural starch suspension could improve the physicochemical properties of natural starch such as viscosity, gelling property, water binding capacity, and lotion stability. Hence, FVPs are widely used in the modification of natural anthocyanins/starch. A systematic review of the latest research progress and future development prospects of FVPs is very necessary to better understand them. This paper systematically reviews the latest progress in the extraction, purification, structure, and analysis techniques of FVPs. Moreover, the review also introduces the potential mechanisms, evaluation methods, and applications of the interaction between polysaccharides and anthocyanins/starch. The findings can provide important references for the further in-depth development and utilization of FVPs.

Comparison of structures and emulsifying properties between water-extracted pectins from Fructus aurantii

The structural characteristics of two water-extracted pectic polysaccharides from Fructus aurantii were investigated, and the impacts of their structures on the emulsifying stability were evaluated. FWP-60 (extracted by cold water and followed 60 % ethanol precipitation) and FHWP-50 (extracted by hot water and followed 50 % ethanol precipitation) were both high methyl-esterified pectins, which were composed of homogalacturonan (HG) and highly branched rhamnogalacturonan I (RG-I) regions. The weight-average molecular weight, methyl-esterification degree (DM) and HG/RG-I ratio of FWP-60 were 1200 kDa, 66.39 % and 4.45, respectively, which were 781 kDa, 79.10 % and 1.95 for FHWP-50. The methylation and NMR analysis of FWP-60 and FHWP-50 demonstrated that the main backbone consisted of different molar ratios of →4)-α-GalpA-(1 → and →4)-α-GalpA-6-O-methyl-(1→, and the side chains contained arabinan and galactan. Moreover, the emulsifying properties of FWP-60 and FHWP-50 were discussed. Compared with FHWP-50, FWP-60 had better emulsion stability. Overall, pectin had a linear HG domain and a small number of RG-I domain with short side chains to facilitate the stabilization of emulsions in Fructus aurantii. A comprehensive knowledge of the structure characteristic and emulsifying property would enable us to provide more information and theoretical guidance for the structure and emulsion preparation of Fructus aurantii pectic polysaccharides.

Salvia miltiorrhiza polysaccharide and its related metabolite 5-methoxyindole-3-carboxaldehyde ameliorate experimental colitis by regulating Nrf2/Keap1 signaling pathway

The roots of Salvia miltiorrhiza have been used in Traditional Chinese Medicine for thousands of years. However, tons of aerial parts of this plant are usually discarded in the production of roots preparation. To make better use of these plant resources, the polysaccharide isolated from the aerial part of S. miltiorrhiza was investigated for its potential protection against intestinal diseases. A pectic polysaccharide (SMAP-1) was isolated and characterized being composed of homogalacturonan as the main chain and rhamnogalacturonan type I as ramified region, with side chains including arabinans and possible arabinogalactan type I and II. SMAP-1 exhibited robust protective effects against dextran sodium sulfate (DSS)-induced colitis and restored colitis symptoms, colonic inflammation, and barrier functions. Anti-oxidative effects were also observed by up-regulating Nrf2/Keap1 signaling pathway. Additionally, the level of serum 5-methoxyindole-3-carboxaldehyde (5-MC) was restored by SMAP-1 identified in metabolomic analysis, being correlated with the aforementioned effects. Protection against oxidative stress on intestinal porcine enterocyte cells (IPEC-J2) by 5-MC was observed through the activation of Nrf2/Keap1 system, as also shown by SMAP-1. In conclusion, SMAP-1 could be a promising candidate for colitis prevention, and 5-MC could be the signal metabolite of SMAP-1 in protecting against oxidative stress in the intestine.

Current progress in valorization of food processing waste and by-products for pectin extraction

Food processing waste and by-products such as peel of citrus fruit, melon, mango, pineapple, etc. and fruit pomace can be utilized for manufacturing of several high-value products. Valorization of these waste and by-products for extraction of pectin, can help offset growing environmental concerns, facilitate value-addition of by-products and their sustainable uses. Pectin has many applications in food industries such as gelling, thickening, stabilizing, and emulsifying agent, and as a dietary fibre. This review elaborates on various conventional and advanced, sustainable pectin extraction techniques, and paints a comparative picture between them considering extraction efficiency, quality, and functionality of the pectin. Conventional acid, alkali, and chelating agents-assisted extraction have been profusely used for pectin extraction, but advanced extraction technologies e.g., enzyme, microwave, supercritical water, ultrasonication, pulse electric field and high-pressure extraction are preferred due to less energy consumption, better quality product, higher yield, and minimal or no generation of harmful effluent.

Extraction, purification, structural characterization, and hepatoprotective effect of the polysaccharide from purple sweet potato

BACKGROUND

Purple sweet potato Ipomoea batatas (L.) has long been used as a medicine and a food. It contains various bioactive substances such as polysaccharides, anthocyanins, and flavonoids. Purple sweet potato polysaccharides are known to have anti-oxidant, anti-tumor, and immunomodulatory functions. Nevertheless, studies on the structural characterization of purple sweet potato polysaccharides and their ability to prevent non-alcoholic fatty liver disease (NAFLD) have rarely been reported.

RESULTS

A novel polysaccharide (PSPP-A) was extracted and isolated from purple sweet potato, and its structural characteristics and preventive effects on NAFLD were investigated. The results indicated that PSPP-A was composed of l-rhamnose, d-arabinose, d-galactose, d-glucose, and d-glucuronic acid with molar ratios of 1.89:8.45:1.95:1.13:1. Its molecular weight was 2.63 × 10³  kDa. Methylation and nuclear magnetic resonance (NMR) analysis indicated that the glycosidic linkages were →3)-α-L-Araf-(1→, α-L-Araf-(1→, →2,4)-α-L-Rhap-(1→, 4-O-Me-β-D-GlcAp-(1→, →4)-α-D-Glcp-(1→, →4)-β-D-Galp-(1→, and →6)-β-D-Galp-(1→. Scanning electron microscopy (SEM) indicated that the structure of PSPP-A was irregular. Subsequently, the protective effect of PSPP-A on NAFLD was investigated. The results indicated that bodyweight, liver index, and triglyceride (TG), total cholesterol (TC), aspartate transaminase (AST), and alanine transaminase (ALT) content were significantly reduced by intervention of purple sweet potato polysaccharide-A (PSPP-A) compared with the - high-fat diet group. Liver histopathological analysis indicated that PSPP-A attenuated irregular hepatocyte patterns and excessive lipid vacuoles.

CONCLUSIONS

The novel polysaccharide, PSPP-A, mainly contains arabinose, which has certain preventive effects on NAFLD. This study provides a theoretical basis for further elucidating the hepatoprotective effect of purple sweet potatoes as a functional food. © 2022 Society of Chemical Industry.

Structure-function relationships of pectic polysaccharides from broccoli by-products with in vitro B lymphocyte stimulatory activity

To study structure-function relationships of pectic polysaccharides with their immunostimulatory activity, broccoli by-products were used. Pectic polysaccharides composed by 64 mol% uronic acids, 18 mol% Ara, and 10 mol% Gal, obtained by hot water extraction, activated B lymphocytes in vitro (25-250 μg/mL). To disclose active structural features, combinations of ethanol and chromatographic fractionation and modification of the polysaccharides were performed. Polysaccharides insoluble in 80 % ethanol (Et80) showed higher immunostimulatory activity than the pristine mixture, which was independent of molecular weight range (12-400 kDa) and removal of terminal or short Ara side chains. Chemical sulfation did not promote B lymphocyte activation. However, the action of pectin methylesterase and endo-polygalacturonase on hot water extracted polysaccharides produced an acidic fraction with a high immunostimulatory activity. The de-esterified homogalacturonan region seem to be an important core to confer pectic polysaccharides immunostimulatory activity. Therefore, agri-food by-products are a source of pectic polysaccharide functional food ingredients.

Isolation, structure identification, and immunostimulatory effects in vitro and in vivo of polysaccharides from Onosma hookeri Clarke var. longiforum Duthie

BACKGROUND

This study characterized an acidic polysaccharide (OHC-LDPA) isolated from the medicinal and edible homologous plant Onosma hookeri Clarke var. longiforum Duthie. The structure of OHC-LDPA was elucidated based on the analysis of infrared, one-/two-dimensional nuclear magnetic resonance, and gas chromatography-mass spectrometry data. The immunostimulatory effects of OHC-LDPA were identified by both in vitro and in vivo models.

RESULTS

The structure of OHC-LDPA was elucidated as a typical pectin polysaccharide, consisting of galacturonic acid, galactose, arabinose, and rhamnose as the primary sugars, with linear galacturonic acid as the main chain and arabinogalacturonic acid as the main branched components. OHC-LDPA could significantly stimulate the proliferation and phagocytosis of RAW264.7 macrophages and the release of nitric oxide in vitro. Also, it could accelerate the recovery of spleen and thymus indexes, enhance the splenic lymphocyte proliferation responses, and restore the levels of interleukin-2, interleukin-10, interferon-γ, and immunoglobulin G in the serum in a cyclophosphamide-induced immunosuppressed-mice model. In addition, OHC-LDPA could restore the intestinal mucosal immunity and reduce the inflammatory damage.

CONCLUSION

OHC-LDPA could improve the immunity both in vitro and in vivo and could be used as a potential immunostimulant agent. © 2022 Society of Chemical Industry.

An Overview of Antitumour Activity of Polysaccharides

Cancer incidence and mortality are rapidly increasing worldwide; therefore, effective therapies are required in the current scenario of increasing cancer cases. Polysaccharides are a family of natural polymers that hold unique physicochemical and biological properties, and they have become the focus of current antitumour drug research owing to their significant antitumour effects. In addition to the direct antitumour activity of some natural polysaccharides, their structures offer versatility in synthesizing multifunctional nanocomposites, which could be chemically modified to achieve high stability and bioavailability for delivering therapeutics into tumor tissues. This review aims to highlight recent advances in natural polysaccharides and polysaccharide-based nanomedicines for cancer therapy.

Structural characterization and immunoregulatory activity of a neutral polysaccharide from the roots of Apocynum venetum L

The structural characteristics and immunoregulatory activities of neutral heteropolysaccharide (AVRP-N) separated from the roots of Apocynum venetum L. were extensively investigated. The results showed that the weight average molecular mass (Mw) of AVRP-N was 6.430 × 10³ Da. Moreover, the backbone is composed of natural acetylated (1 → 4)-β-D-Man and (1 → 5)-α-L-Ara domains. The mannan is composed of →4)-β-D-Manp-(1→, →4)-β-D-Glcp-(1→, and the terminal group α-D-Galp-(1→ attached to →4,6)-β-D-Manp-(1→ at O-6. Araban is composed of →5)-α-L-Araf-(1→; the terminal group α-L-Araf-(1→attached to→2,3,5)-α-L-Araf-(1→ at O-2, O-3 and →3,5)-α-L-Araf-(1→ at O-3. In addition, the senior structure shows that AVRP-N has a triple-helix conformation. Furthermore, AVRP-N exhibited immunomodulatory effects, which could significantly regulate the proliferation of mouse splenic lymphocytes by enhancing the secretion of the cytokines (IFN-γ, IL-2, IL-4, and IL-10). Our results provide new structural and immunoregulatory information for natural polysaccharides derived from Apocynum venetum L.

Structural characterization and anti-osteoporosis activity of two polysaccharides extracted from the rhizome of Curculigo orchioides

Curculigo orchioides is widely used to treat osteoporosis in China. In this study, we identified the active substances in the crude polysaccharide (CO50) from C. orchioides that had anti-osteoporosis activity in vivo. Two polysaccharides, COP50-1 and COP50-4, were purified from CO50. Based on structural analysis, COP50-1 was composed of α-D-Glcp-(1→, β-D-Galp-(1→, →4)-α-D-Glcp-(1→, →3,4)-α-D-Glcp-(1→, →4,6)-α-D-Glcp-(1→, →4,6)-β-D-Manp-(1→, whereas COP50-4 was composed of α-L-Araf-(1→, →2)-α-L-Rhap-(1→, β-D-Manp-(1→, α-D-Galp-(1→, →2,4)-α-L-Rhap-(1→, →2)-β-D-Manp-(1→, →4)-α-D-GlcAp-(1→, →3)-α-D-GalAp-(1→, →4,6)-α-D-Galp-(1→, →2,3,6)-β-D-Manp-(1→, →2,3,5)-α-L-Araf-(1→, →2,5)-α-L-Araf-(1→, →4)-α-D-Glcp-(1→ and →3)-α-D-Galp-(1→. Pharmacological assessment revealed that COP50-1 had no obvious osteogenic activity. However, COP50-4 (0.5 μM) significantly enhanced the differentiation and mineralization of osteoblasts in vitro. Moreover, the effect of COP50-4 was greater than that of 17β-estradiol. Therefore, COP50-4 may be an effective component of CO50 that has great potential for development as an alternative drug for the treatment of osteoporosis.

Structural features and anticancer mechanisms of pectic polysaccharides: A review

The anticancer activity of pectic polysaccharides (PPs) was proved by numerous studies, and which also indicated that the bioactivity of PPs was closely related to its complicated structures. Based on the summary and analysis about structure characteristics and corresponding enzymatic process of the reported PPs, the anticancer mechanism and related structural features were systematically clarified. It was found that not only the direct effects on the cancer cells by proliferation inhibition or apoptosis, but also the regulation of immune system, gut microbiota and gut metabolism as indirect effects, jointly played important roles in the anticancer of PPs. Nevertheless, during the study of PPs as promising anticancer components, the exact structure-function relationship, digestion process in vivo, and comprehensive action mechanism are still not well understanding. With the unveiling of the proposed issues, it is believed that PPs are promising to be exploited as effective cancer therapy/adjunctive therapy drugs or functional foods.

Structural Characterization of a Low Molecular Weight HG-Type Pectin From Gougunao Green Tea

Tea is a popular beverage with a long history of safe and healthy use. Tea polysaccharide is a bioactive component extracted from tea, which has attracted more and more attention in recent decades. In this article, an acidic polysaccharide Gougunao tea polysaccharide (GPS) was isolated from Gougunao green tea by hot water extraction and ethanol precipitation. After purification by a diethylaminoethyl (DEAE) Sepharose Fast Flow column and a Sephacryl S-400 column, several homogalacturonan (HG) and rhamnogalacturonan-I (RG-I) fractions were obtained. Fraction GPS2b with the highest yield was selected for structural characterization by methylation and nuclear magnetic resonance (NMR) analysis. GPS2b was found to be an HG-type pectic polysaccharide (degree of methyl esterification [DE], 51.6%) with low molecular weight (Mw, 36.8 kDa). It was mainly composed of →4)-α-GalpA- (1→ and →4)-α-GalpA-6-OMe-(1→. In addition, a minor highly branched RG-I domain was identified in this fraction. The investigation of structural features of tea polysaccharides can provide insights to understand their structure-bioactivity relationship.

Structure and immunological activity of an arabinan-rich acidic polysaccharide from Atractylodes lancea (Thunb.) DC

An arabinan-rich acidic polysaccharide, named ALP4-2 ([α]20 D = +197.8 (c 1.0 mg/mL, H₂O); and M_w = 5.59 × 10³ g/mol), was obtained from Atractylodes lancea (Thunb.) DC. ALP4-2 is mainly comprised of Ara along with a small amount of GalA, Gal, Rha, Glc and Xyl. The structure was decorated by glycosidic linkages of α-Araf-(1→, →3)-α-Araf-(1→, →5)-α-Araf-(1→, →3,5)-α-Araf-(1→, →2,4)-α-Rhap-(1→, α-GalAp-(1→, →4)-α-GalAp-6-OMe-(1→, →4)-α-GalAp-6-OMe and β-Galp-(1→ with a ratio of 6:1:7:5:5:1:7:1:4. The structure, configuration and microstructure of ALP4-2 was proposed by comprehensive considerations of results from SEC-MALLS-RID, SEC-HRMS, GC-MS, and 1D/2D NMR spectroscopy. Except for a high methyl ester in full pectin regions, an abundant arabinan moiety is observed in ALP4-2 with highly complex and branched characteristics. The immunoactivity displayed that ALP4-2 can significantly promote phagocytosis of macrophage without cytotoxicity, and stimulate nitric oxide and cytokines (TNF-α, IL-6 and IL-10) release on RAW 264.7.

Structure and functionality of Rhamnogalacturonan I in the cell wall and in solution: A review

Rhamnogalacturonan I (RG-I) belongs to the pectin family and is found in many plant cell wall types at different growth stages. It plays a significant role in cell wall and plant biomechanics and shows a gelling ability in solution. However, it has a significantly more complicated structure than smooth homogalacturonan (HG) and its variability due to plant source and physiological state contributes to the fact that RG-I's structure and function is still not so well known. Since functionality is a product of structure, we present a comprehensive review concerning the chemical structure and conformation of RG-I, its functions in plants and properties in solutions.

P. granatum Peel Polysaccharides Ameliorate Imiquimod-Induced Psoriasis-Like Dermatitis in Mice via Suppression of NF-κB and STAT3 Pathways

Psoriasis is a chronic and refractory inflammatory and autoimmune-mediated cutaneous disease affecting approximately 2%–3% of the global population. Most of the current therapies could relieve symptoms rapidly, while the side effects cannot be negligible. Hence, it is urgent to explore much safer and more effective treatments. In the current work, we evaluated the potential beneficial effect of Punica granatum peel polysaccharides (PPPs) in an imiquimod-elicited psoriasis-like mouse model and unraveled their mechanism of action. Firstly, PPPs were isolated from P. granatum peels, and then the molecular weight was determined and monosaccharide analysis was performed. The results revealed that PPPs significantly ameliorated psoriasis-like skin lesions and reduced the Psoriasis Area and Severity Index (PASI) scores and transepidermal water loss (TEWL). PPPs also attenuated the expressions of CD3 and Ki67 in psoriasis-like mouse skin and suppressed the serum or skin levels of pro-inflammatory cytokines, such as tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), IL-1β, IL-8, IL-17, and IL-23. Moreover, PPPs were able to upregulate the mRNA and protein expressions of aquaporin-3 (AQP3) and filaggrin (FLG) in the skin of mice. In addition, PPPs inhibited the NF-κB and STAT3 signaling pathways. Overall, these results indicated that PPPs ameliorated the symptoms of psoriasis through inhibition of the inflammatory cytokines by suppressing the NF-κB and STAT3 signaling pathways and improved skin barrier protection via enhancing AQP3 and FLG. These observations potentially contribute to providing theoretical and experimental evidence for the clinical application of PPPs for psoriasis.

Small berries as health-promoting ingredients: a review on anti-aging effects and mechanisms in Caenorhabditis elegans

Aging is an inevitable, irreversible, and complex process of damage accumulation and functional decline, increasing the risk of various chronic diseases. However, for now no drug can delay aging process nor cure aging-related diseases. Nutritional intervention is considered as a key and effective strategy to promote healthy aging and improve life quality. Small berries, as one of the most common and popular fruits, have been demonstrated to improve cognitive function and possess neuroprotective activities. However, the anti-aging effects of small berries have not been systematically elucidated yet. This review mainly focuses on small berries' anti-aging activity studies involving small berry types, active components, the utilized model organism Caenorhabditis elegans (C. elegans), related signaling pathways, and molecular mechanisms. The purpose of this review is to propose effective strategies to evaluate the anti-aging effects of small berries and provide guidance for the development of anti-aging supplements from small berries.

Structural characterization and immunoregulatory activity of polysaccharides from Dendrobium officinale leaves

In this study, two kinds of polysaccharides from leaves of Dendrobium officinale, namely DLP-1 and DLP-2, were obtained by hot water extraction, ethanol sedimentation, and chromatographic separation using DEAE-52 cellulose and Sephadex G-100 columns. They were composed of different monosaccharides and the content of monosaccharides varied significantly while DLP-1 (M_w 1.38 × 10⁶  Da) was mainly composed of mannose (71.69%) and glucose (22.89%), and DLP-2 (M_w 1.93 × 10⁶  Da) was constituted by rhamnose (35.05%), arabinose (24.12%), and galactose (25.65%). A triple-helical conformation was exhibited by both of them. The scanning electron microscope image of DLP-1 showed an irregular and large lamellar shape, as well as a smooth surface and a porous interior, illustrating they had an amorphous structure. In contrast, DLP-2 revealed a rough, loose, and uneven surface consisting of large sponge-like particles. Nuclear magnetic resonance analysis showed that (1→4)-β-D-Manp, (1→4)-β-D-Glcp, and (1→4)-2-O-acetyl-β-D-Manp were the main linkage types of DLP-1, whereas DLP-2 was constituted by a large amount of (1→4)-β-D-Manp, (1→4)-β-D-Glcp, and other residues. Besides, DLP-1 and DLP-2 stimulated the proliferation and phagocytic capacities of RAW 264.7 cells and improved the production of nitric oxide, interleukin-6, TNF-α, and IL-1β. These results proved that both DLP-1 and DLP-2 possessed excellent immunoregulatory bioactivities and could be functional food or adjuvant drug. PRACTICAL APPLICATIONS: The leaf of Dendrobium officinale is a by-product with huge biomass. The lack of systematic research on its chemical composition and pharmacologic effect, leading to a great waste of resources. In order to maximize the value of D. officinale, this study aimed to investigate the structural characteristics and immunologic effects of two polysaccharide fractions (DLP-1 and DLP-2) from D. officinale leaves, showing that DLP-1 and DLP-2 in D. officinale leaves could be used as anti-inflammatory agents to avoid wasting.

Optimizing acid hydrolysis for monosaccharide compositional analysis of Nostoc cf. linckia acidic exopolysaccharide

The exact estimation of monosaccharide composition is important in the primary structure elucidation of polysaccharides. An acid hydrolysis is usually performed for glycosidic bonds cleavage and releasing of monosaccharides. In this study, optimal conditions of total acid hydrolysis using trifluoroacetic acid (TFA) of acidic lactylated Nostoc cf. linckia exopolysaccharide (EPS) were investigated by NMR spectroscopy. Results of a series of experiments with modified acid concentration, temperature and time of hydrolysis, have shown 2 M TFA, 110 °C, 3 h as the most optimal. The stability of EPS monosaccharide components was also explored. Low stability was found at all tested conditions already during the first hour of hydrolysis; all neutral monosaccharides were degraded from 25% to 40% and glucuronic acid to 75%. NMR, contrary to standard techniques used in monosaccharide compositional analysis (HPLC, HPAEC), allowed simultaneous quantification of all GlcA forms; the free one, that one linked in oligosaccharides, as well as GlcA degradation product γ-lactone. NMR as detection method improves information about uronic acid content in EPS.

Improving the Viability and Metabolism of Intestinal Probiotic Bacteria Using Fibre Obtained from Vegetable By-Products

This study evaluated the effect of dietary fibre obtained from pomegranate, tomato, grape and broccoli by-products on the gastrointestinal transit survival, growth, and metabolism of six probiotic strains. The results showed that the studied by-products contained variable amounts of polysaccharides that affected the six probiotic microorganisms in different ways. In addition, the protective effect of the fibre obtained on the probiotic strains was more effective in the case of the fibre obtained from tomato peel. In terms of growth, grape stems showed the best results, favouring the growth of lactic acid bacteria. Finally, all fibres were able to increase the content of short-chain fatty acids in the in vitro test, but broccoli stems and pomegranate peel stimulated higher production of short-chain fatty acids. The results of this study demonstrate that plant by-product fibres can improve survival, growth, and metabolism in terms of the fatty acid profiles of probiotic strains, highlighting the desirability of harnessing these by-product fibres to develop new high-value-added ingredients as probiotic carriers.

Strategies to Increase the Biological and Biotechnological Value of Polysaccharides from Agricultural Waste for Application in Healthy Nutrition

Nowadays, there is a growing interest in the extraction and identification of new high added-value compounds from the agro-food industry that will valorize the great amount of by-products generated. Many of these bioactive compounds have shown beneficial effects for humans in terms of disease prevention, but they are also of great interest in the food industry due to their effect of extending the shelf life of foods by their well-known antioxidant and antimicrobial activity. For this reason, an additional research objective is to establish the best conditions for obtaining these compounds from complex by-product structures without altering their activity or even increasing it. This review highlights recent work on the identification and characterization of bioactive compounds from vegetable by-products, their functional activity, new methodologies for the extraction of bioactive compounds from vegetables, possibly increasing their biological activity, and the future of the global functional food and nutraceuticals market.

Structural characteristics of three pectins isolated from white kidney bean

Three water-soluble pectic polysaccharides (WKBP-P2, P3 and P4) were isolated from white kidney bean by ion exchange combined with size-exclusion methods. The structural features were characterized by GC-MS, NMR spectroscopy and HPSEC-MALLS-RI. It was found that three pectic polysaccharides were the major water-extracted polysaccharides in white kidney bean. All the WKBP-P2, P3 and P4 were probably composed of various structural regions including homogalacturonan (HG), xylogalacturonan (XGA), rhamnogalacturonan I (RG-I) regions in backbone, and arabinan region mainly as side chain. However, these pectic polysaccharides were significantly different in molar ratios of these structural regions and molecular size. WKBP-P2 was HG-predominant pectin (partially methyl-esterified) with weight-average molecular weight (M_w) of 1.2 × 10⁴ g/mol, and contained minor RG-I, arabinan and probable XGA regions. WKBP-P3 (M_w of 4.0 × 10⁴ g/mol) primarily embraced XGA, HG, arabinan regions and minor RG-I region. WKBP-4 with highest M_w (4.5 × 10⁵ g/mol) had the most arabinan region (51.3%), which was probably the side chain linked to the backbone composed of RG-I, HG and slight XGA regions. These findings provided a structural basis for study on polysaccharides from white kidney bean, which was benefit for development of functional food.