Structure-function relationship of licorice (Glycyrrhiza glabra) root extract-xanthan/guar gum mixture in a high sugar content system.

BACKGROUND: Foam-gels are one of the most important multicomponent-model systems in aerated confectionery, and an investigation of their microstructure is desirable. In this research, the structure-function relationship of xanthan gum/guar gum (XG/GG) and licorice (Glycyrrhiza glabra) root extract powder (LEP) was investigated in a high-sugar medium. Foam-gel systems were prepared at 4:10% to 8:20% ratios of LEP to biopolymer. RESULTS: The results show that increasing the LEP content reduced both the melting point and enthalpy, probably due to higher overrun and weaker junctions. Boosting the XG/GG ratio led the enhancement of mechanical properties, whereas increasing the LEP concentration weakened all textural parameters, which could be due to the poor structure of the network in the presence of the foaming agent, increased moisture content and overrun. In the whipped mixture samples containing 10 g kg-1 XG/GG, higher foaming capacity was observed. By increasing the level of biopolymers, smaller and more uniform air cells were formed according to a scanning electron microscopical study. At higher concentration of LEP, smaller bubbles and increased porosity were seen, which could be attributed to the availability of surfactant in the interfacial layer. CONCLUSION: Maximum structural strength was achieved at a 4:20 ratio of LEP to XG/GG. In rheological experiments, pseudoplastic behavior was seen in all samples. Generally, this model system can be simulated for other herbal extracts containing natural surfactants such as saponins. Achieving a more detailed understanding of these structures and their interactions could help in formulating novel food products. © 2021 Society of Chemical Industry.

Effects of seleno-Sesbania canabina galactomannan on anti-oxidative and immune function of macrophage.

Seleno-polysaccharides have become a major topic for research owing to their high anti-oxidative capacity and immune-enhancing activities. In this study, galactomannan (GM) was isolated from Sesbania cannabina, and next modified using HNO3-Na2SeO3 method to obtain six varieties of seleno-galactomannans (SeGMs). FT-IR and GPC results showed the changes in chemical structure of SeGMs, indicating successful combination of selenium and GM. By measuring superoxide dismutase and malondialdehyde, the SeGMs showed a stronger protective effect against H2O2-induced oxidative damage in vitro than unmodified GM using macrophage RAW264.7 cell as a model, and the effect of SeGMs-14 was prominent. However, the selenylation modification did not show any obvious effect on the immunomodulatory activity of GM, as determined by the index of tumor necrosis factor-α, interleukin-6, and interleukin-1ß. Overall, the prepared SeGMs from galactomannan could potentially serve as a dietary supplement of Se or an organic antioxidant.

Selective extraction of galactomannan from fenugreek (Trigonella foenum-graecum L.) seed husk and its enzyme inhibitory potential associated with hyperglycaemia.

BACKGROUND: Fenugreek seeds host various bioactive compounds, and galactomannan (GM) is a significant soluble fibre. In this study, selective extraction is adapted to extract fenugreek seed GM to improvise the yield recovery. The seeds are fractionated, separated and classified as husk and cotyledons. Comparative studies have been performed to evaluate the crude and pure GM yield between different groups such as the whole seed, and the classified fractions. Characterization is done using Fourier transform infrared, differential scanning calorimetry, scanning electron microscopy, monosaccharide composition and optical density, and the structure is elucidated through nuclear magnetic resonance. The GM obtained through extraction is used to study its enzyme inhibitory property associated with hyperglycaemia. RESULTS: GM yield extracted from the husk is highly significant compared to other groups. Crude GM and pure GM yield was 2 and 3.25 times higher than that obtained through whole seed samples. The characterization of the pure GM is on a par with the existing reports. The purified GM inhibited α-amylase and α-glucosidase enzymes in vitro, with an IC50 of 21.08 ± 0.085 and 67.17 ± 5.15 µg mL-1 , respectively. CONCLUSION: Selective extraction prompts enhancement in the recovery of the bioactive compound, minimal use of resources, and promotes industrial viability. Characterization of the compound confirms the structure. Its enzyme inhibitory property makes GM a valuable compound in diabetic prevention/treatment. © 2021 Society of Chemical Industry.

Structural characteristics of oxalate-soluble polysaccharides from Norway spruce (Picea abies) foliage.

Structurally different polymers were derived from Picea abies foliage by successive extraction with water (PAW), HCl solution (PAA) and (NH4)2C2O4 solution (PAO). The P. abies foliage was found to contain basically low-methoxyl pectin extractable with an (NH4)2C2O4 solution. PAW was shown to comprise primarily arabinogalactan-proteins (AGPs); PAA was composed of mixed AGPs and pectic polysaccharides, with the latter prevailing; and polysaccharide PAO isolated in the highest yield included chiefly pectic polysaccharides. The major constituents of PAO were low-methoxyl and low-acetylated 1,4-α-d-galacturonan and partially acetylated RG-I. The sugar side chains of RG-I contained chiefly highly branched 1,5-α-l-arabinan and arabinogalactan type I as a minor constituent. RG-I whose side chains had 1,5-α-l-arabinan represented short regions alternating with non-acetylated and unmethylesterified galacturonan regions. In addition to pectins, polysaccharide PAO contained AGPs, xylanes and glucomannans, indicating that these polysaccharides are in an intimate interaction.

Extraction, purification, and determination of the gastroprotective activity of glucomannan from Bletilla striata.

In this study, a water-soluble polysaccharide (BSP) was extracted and purified from pseudobulb of Bletilla striata. The preliminary structure and gastroprotective activity of BSP were analyzed. Results indicate that BSP is a glucomannan with a molar ratio of 7.45:2.55 (Man:Glc), and its molecular weight is approximately 1.7 × 105 Da. BSP displayed outstanding protective action against ethanol-induced GES-1 cell injury in vitro, as well as, excellent gastroprotective activity in vivo. Especially, a high-dose of BSP (100 mg/kg) could reduce the ulcer index of the gastric mucosa and increase the percentage of ulcer inhibition, which possibly caused by enhancing the antioxidant capacity and inhibiting the apoptotic pathway in gastric tissue. Interestingly, BSP exhibited a comparative gastroprotective activity to that of positive control (omeprazole). In summary, our results indicated that BSP could be considered as a potential supplement for the prevention of gastric injury.

Comparative study on glucomannans with different structural characteristics: Functional properties and intestinal production of short chain fatty acids.

Glucomannans (GMs) from abundant natural resources have excellent processing properties and plentiful bioactivities. In current study, functional properties of GMs with different structural characteristics, including KGM from konjac, DOP from dendrobium, AGP40, ASP-4N, ASP-6N, & ASP-8N from aloe were determined. Results suggested that molecular weights (Mw) of GMs were positively correlated with their water absorption capacity, fat absorption capacity, and viscosity, while ratio of mannose/glucose showed negative effect. Higher degree of acetylation (DA) mainly corresponded to higher values of solubility and ζ-potential. Then, effects of the six GMs on general health status, serum biochemicals, and intestinal SCFAs production in mice were evaluated in vivo. Analysis of general health status and levels of serum biochemicals revealed that mice with consecutive supplementation of GMs for 14 days performed normally compared with those in control group. Interestingly, the productions of SCFAs (mainly acetate and butyrate) in the cecal and colonic contents were significantly promoted. Generally, higher concentrations of SCFAs were produced when mice were treated with GMs having higher Mw, ratio of glucose, and DA. The current investigation suggested that both functional and intestinal fermentation property of GMs were jointly determined by the monosaccharide composition, molecular weight, and degree of acetylation.

Biomimetic galactomannan/bentonite/graphene oxide film with superior mechanical and fire retardant properties by borate cross-linking.

With the great demand for high-strength integrated materials in various industries, products from renewable resources were expected to replace petroleum-based materials. Inspired by the hierarchical structure of nacre, in this work, bentonite and graphene oxide (GO) were incorporated into the galactomannan (GM) matrix to prepare a ternary nanocomposite, which was further cross-linked and strengthened with borate. The chemical structure of the composite was analyzed with SEM, FTIR, XPS and XRD, revealing a co-assembly reaction between GO, bentonite and GM, accompanied by the borate crosslinking. This synergistic strengthen effect resulted in a composite possessing a maximum tensile stress and toughness of 231.16 MPa and 4.53 MJ/m3, respectively, harder than most of the previously reported hemicellulose composites. Moreover, the nanocomposites showed excellent fire retardant property with a limiting oxygen index of 46.8 % due to the introduction of bentonite and GO, which shows potential application in fire-protective insulation, packaging and coating.

Colloidal features of softwood galactoglucomannans-rich extract.

Development of a sustainable bioeconomy requires valorization of renewable resources, such as wood hemicelluloses. The intra- and inter-molecular association of hemicelluloses within themselves or with other wood components can result in complex macromolecular features. These features exhibit functionality as hydrocolloids, however macromolecular characterization of these heterogeneous materials are challenging using conventional techniques such as size-exclusion chromatography. We studied galactoglucomannans (GGM) -rich softwood extracts at two grades of purity-as crude extract and after ethanol-precipitation. Asymmetrical flow field-flow fractionation (AF4) was optimized and utilized to fractionate size classes in GGM extracts, and subsequent characterization was performed with light scattering and microscopy techniques. Both GGM extracts contained polysaccharides of around 10,000 g/mol molar mass, and colloidal assemblies and/or particles in sub-micron size range. The optimized AF4 method facilitates the characterization of complex biomass-derived carbohydrates without pre-fractionation, and provides valuable understanding of their unique macromolecular features for their future application in food, pharmaceuticals, and cosmetics.

Procuring biologically active galactomannans from spent coffee ground (SCG) by autohydrolysis and enzymatic hydrolysis.

Spent coffee grounds (SCG) are a promising raw material for galactomannan (GalM) production based upon its enrichment in galactomannan polysaccharides. In this work, SCG was pretreated by autohydrolysis for maximumly improving GalM extractability by endo-mannanase. The GalM in the prehydolyzate (GalM-PH) and enzymatic hydrolyzate (GalM-EH) were obtained by ethanol precipitation and characterized. Under the optimized autohydrolysis conditions, 50.1% of GalM in pretreated SCG was converted into free GalM in enzymatic hydrolyzate. Compositional analysis results revealed that GalM-PH was comprised of 81.7% galactomannan, higher than that of GalM-EH (76.4%). The molecular weight of GalM-PH and GalM-EH were 44.5 kDa and 28.0 kDa, respectively. Antioxidant assays indicated that both GalM-EH and GalM-PH could scavenge 2,2-diphenyl-1-picryl-hydrazyl radicals and hydroxyl radicals. Immunological and prebiotics analysis showed all GalM preparations exhibited pronounced activities for proliferating the probiotics and proliferating the Macrophages cell for NO production, in which the GalM-EH outperformed the GalM-PH. These results imply that the GalM extracted from SCG are the bioactive substances that can be used as antioxidant, prebiotics, and immunostimulants.

Fabrication and characterization of herbal drug enriched Guar galactomannan based nanofibrous mats seeded with GMSC's for wound healing applications.

Electrospun nanofibrous Guar gum/PVA based scaffold matrix incorporated with standardized extracts of four traditional medicinal plants of wound healing repute namely - Acalypha indica (A.i), Aristolochia bracteolata (A.b), Lawsonia inermis (L.i) and Thespesia populnea (T.p) was developed. Combinatorial ratio optimization of the extracts subject to their impact on nanofibre morphology, thermal and swelling stability resulted in a 4:4:1:1 blend of A.i, A.b, T.p and L.i at 20% of the total weight of the polymer mix. Dermal toxicity studies on female wistar rats established the nontoxicity of the generated Scaffold/Dressing. Cutaneous wound healing ability of Mesenchymal Stem Cells (MSC's) is well characterized to amplify their delivery and efficacy at the wound site. Apart from ease of accessibility, increased immune modulation of Gingival MSC's is their clear merit relative to those conventionally sourced from adipose tissues and bone marrow. A population of cells were isolated from discarded sample of human gingiva, following standard procedures and characterized as per minimal criteria as described by International Society for Cellular Therapy's (ISCT). The Cytocompatibility and proliferation of GMSC's were evaluated by MTT and Calcein AM assay demonstrating the viability of the seeded GMSC's up to 6 days. In vivo efficacy of the scaffold with and without GMSC's showed complete restoration of the tissue with minimal scarring. This investigation thus generated an herb drug enriched nanofibrous mat as a dressing and also a skin like scaffold with GMSC's, integrating the biological and technological benefits of herbal medicine and stem cell therapy respectively for skin regenerative applications.

Extraction, Purification, Structural Characteristics, Biological Activities and Pharmacological Applications of Acemannan, a Polysaccharide from Aloe vera: A Review.

: Aloe vera is a medicinal plant species of the genus Aloe with a long history of usage around the world. Acemannan, considered one of the main bioactive polysaccharides of Aloe vera, possesses immunoregulation, anti-cancer, anti-oxidation, wound healing and bone proliferation promotion, neuroprotection, and intestinal health promotion activities, among others. In this review, recent advancements in the extraction, purification, structural characteristics and biological activities of acemannan from Aloe vera were summarized. Among these advancements, the structural characteristics of purified polysaccharides were reviewed in detail. Meanwhile, the biological activities of acemannan from Aloe vera determined by in vivo, in vitro and clinical experiments are summarized, and possible mechanisms of these bioactivities were discussed. Moreover, the latest research progress on the use of acemannan in dentistry and wound healing was also summarized in details. The structure-activity relationships of acemannan and its medical applications were discussed. Finally, new perspectives for future research work on acemannan were proposed. In conclusion, this review summarizes the extraction, purification, structural characteristics, biological activities and pharmacological applications of acemannan, and provides information for the industrial production and possible applications in dentistry and wound healing in the future.

The Combination of Dimorphandra gardneriana Galactomannan and Mangiferin Inhibits Herpes Simplex and Poliovirus.

BACKGROUND: Herpes simplex virus (HSV) and poliovirus (PV) are both agents of major concern in the public health system. It has been shown that Dimorphandra gardneriana galactomannans can be used as solubilizer vehicles in the manufacturing of medicine. Mangiferin is the major constituent of Mangifera indica and presents multiple medicinal and biological activities. OBJECTIVE: This study assayed the effect of D. gardneriana galactomannan combined with mangiferin (DgGmM) against HSV-1 and PV-1. METHODS: The DgGmM cytotoxicity was evaluated by the colorimetric MTT method and the antiviral activity by plaque reduction assay, immunofluorescence and polymerase chain reaction (PCR), in HEp-2 cells. RESULTS: The DgGmM showed a 50% cytotoxic concentration (CC50) > 2000 µg/mL. The 50% inhibitory concentrations (IC50) for HSV-1 and PV-1 were, respectively, 287.5 µg/mL and 206.2 µg/mL, with selectivity indexes (SI) > 6.95 for the former and > 9.69 for the latter. The DgGmM time-ofaddition protocol for HSV-1 showed a maximum inhibition at 500 µg/mL, when added concomitantly to infection and at the time 1 h post-infection (pi). While for PV-1, for the same protocol, the greatest inhibition, was also observed concomitantly to infection at 500 µg/mL and at the times 4 h and 8 h pi. The inhibition was also demonstrated by the decrease of fluorescent cells and/or the inhibition of specific viral genome. CONCLUSION: These results suggested that the DgGmM inhibited HSV-1 and PV-1 replication, with low cytotoxicity and high selectivity and, therefore, represents a potential candidate for further studies on the control of herpes and polio infections.

Anticoagulant Properties of a Green Algal Rhamnan-type Sulfated Polysaccharide and Its Low-molecular-weight Fragments Prepared by Mild Acid Degradation.

The active sulfated polysaccharide from seaweed possesses important pharmaceutical and biomedical potential. In the study, Monostroma sulfated polysaccharide (MSP) was obtained from Monostroma angicava, and the low-molecular-weight fragments of MSP (MSP-Fs: MSP-F1⁻MSP-F6) were prepared by controlled acid degradation. The molecular weights of MSP and MSP-F1⁻MSP-F6 were 335 kDa, 240 kDa, 90 kDa, 40 kDa, 24 kDa, 12 kDa, and 6.8 kDa, respectively. The polysaccharides were sulfated rhamnans that consisted of →3)-α-l-Rhap-(1→ and →2)-α-l-Rhap-(1→ units with partial sulfation at C-2 of →3)-α-l-Rhap-(1→ and C-3 of →2)-α-l-Rhap-(1→. Anticoagulant properties in vitro of MSP and MSP-F1⁻MSP-F6 were evaluated by studying the activated partial thromboplastin time, thrombin time, and prothrombin time. Anticoagulant activities in vivo of MSP and MSP-F4 were further evaluated; their fibrin(ogen)olytic activities in vivo and thrombolytic properties in vitro were also assessed by D-dimer, fibrin degradation products, plasminogen activator inhibitior-1, and clot lytic rate assays. The results showed that MSP and MSP-F1⁻MSP-F4 with molecular weights of 24⁻240 kDa had strong anticoagulant activities. A decrease in the molecular weight of MSP-Fs was accompanied by a decrease in the anticoagulant activity, and higher anticoagulant activity requires a molecular weight of over 12 kDa. MSP and MSP-F4 possessed strong anticoagulant activities in vivo, as well as high fibrin(ogen)olytic and thrombolytic activities. MSP and MSP-F4 have potential as drug or helpful food supplements for human health.

A glucogalactomannan isolated from Agaricus bisporus induces apoptosis in macrophages through the JNK/Bim/caspase 3 pathway.

Agaricus bisporus is one of the most important edible and medicinal mushrooms in the world. It has been well known that Agaricus bisporus has an immunoregulatory role, but its active ingredients have not been completely identified. In this study, a glucogalactomannan named TJ3 was isolated and purified from Agaricus bisporus. TJ3 (827 kDa) is composed of mannose, galactose, glucose and xylose in the ratio 28.26 : 27.82 : 20.88 : 9.87 mainly joined by ß-linkages. Functional analysis of TJ3 revealed that it effectively induced apoptosis in RAW 264.7 cells, a mouse macrophage cell line. Cell apoptosis was determined by an Annexin V/PI staining assay. After treatment with TJ3 (2 µg mL-1) for 16 h, apoptosis was observed in 34% of the Raw cells (9% in the non-treated control cells). TJ3 treatment remarkably increased the production of cleaved caspase-3, PARP and Bim, and decreased the level of Bcl-2 although no obvious change in the level of Bax was observed. Interestingly, further elucidation of the molecular mechanism underlying the role of TJ3 in the induction of apoptosis showed that TJ3 activated the JNK signaling pathway through TLR4 and subsequently promoted the expression of Bim and activation of caspase-3. Our results demonstrate that TJ3 may be a novel active component in Agaricus bisporus responsible for its immunoregulatory role by the induction of macrophage apoptosis.

Depolymerized konjac glucomannan: preparation and application in health care.

Konjac glucomannan (KGM) is a water-soluble polysaccharide obtained from the roots and tubers of konjac plants. Recently, a degraded product of KGM, depolymerized KGM (DKGM), has attracted attention because of its low viscosity, improved hydrophily, and favorable physiological functions. In this review, we describe the preparation of DKGM and its prebiotic effects. Other health benefits of DKGM, covering antioxidant and immune activity, are also discussed, as well as its safety. DKGM could be a candidate for use as a tool for the treatment of various diseases, including intestinal flora imbalance, and oxidative- and immune-related disorders.

Extraction and derivatization of Leucaena leucocephala (Lam.) galactomannan: Optimization and characterization.

Water soluble gums also known as hydrocolloids are increasingly finding applications in the pharmaceutical and food industry due to their versatile functional properties. They possess considerable use in food and pharmaceutical industries as emulsifying, thickening and gelling agents. In the present investigation a heteropolysaccharide galactomannan was extracted from Leucaena leucocephala (Lam.) seeds by an aqueous method, characterized for its compositional analysis (mannose: galactose ratio), physicochemical and functional properties (solubility), and mechanical properties. The extracted gum was derivatized to form its carboxymethyl derivative and the method of its derivatization was optimized by varying the reaction parameters. The native and derivatized gum was characterized by FTIR, XRD, DSC, NMR, SEM and elemental analysis, etc. The yield of Leucaena leucocephala galactomannan (LLG) was found to be 20% (w/w). The optimized parameters for carboxymethylation reaction (degree of substitution 0.805) were found to be 6.0g NaOH, 10.0g MCA, at 60°C for 4h. The physicochemical and functional characteristics of native and derivatized gum suggest its potential role in food and pharmaceutical industries.

Cholesteryl-modification of a glucomannan from Bletilla striata and its hydrogel properties.

A glucomannan-type polysaccharide, named BSP, was obtained from the tubers of Bletilla striata by ultrasonic-assisted extraction, ethanol precipitation, deproteination and gel-permeation chromatography. HPLC analysis revealed that BSP contained mannose and glucose in the molar ratio of 3.5:1. Its molecular weight (Mw) was estimated to be 20 kDa. Methylation analysis, FT-IR and NMR analyses indicated that BSP consisted of (1→4)-linked ß-D-glucopyranosyl residues and (1→4)-linked ß-D-mannopyranosyl residues. Cholesteryl succinate was linked to BSP to make it more amphiphilic and the degree of substitution of cholesteryl succinate-BSP was 3.2%. The critical micelle concentration of modified BSP was 0.001 mg/mL, suggesting it could self-assemble into nanoparticles in aqueous solution.

Sequential microwave superheated water extraction of mannans from spent coffee grounds.

The feasibility of using sequential microwave superheated water extraction (MAE) for the recovery of mannans from spent coffee grounds (SCG) was studied. Due to the high contents of mannose still present in the SCG residue left after two consecutive MAE, the unextracted material was re-suspended in water and submitted to a third microwave irradiation (MAE3) at 200 °C for 3 min. With MAE3, mannose recovery achieved 48%, increasing to 56% by MAE4, and reaching a maximum of 69% with MAE5. Glycosidic-linkage analysis showed that in MAE3 mainly galactomannans were recovered, while debranched galactomannans were recovered with MAE4 and MAE5. With increasing the number of extractions, the average degree of polymerization of the mannans decreased, as observed by size-exclusion chromatography and by methylation analysis. Scanning electron microscopy images showed a decrease on cell walls thickness. After final MAE5, the remaining un-extracted insoluble material, representing 22% of the initial SCG, was composed mainly by cellulose (84%).

Isolation, purification and characterization of galactomannans as an excipient from Senna tora seeds.

Seed galactomannans are neutral, heterogeneous polysaccharides widely distributed in nature. The Mannose/Galactose ratios differ from gum to gum, resulting in a change in structure, which in turn, determines the various industrial applications of seed galactomannans. Senna tora (Family: Fabaceae) is a fast growing and spreading under shrub of which seeds, pods and leaves are extensively used for medicinal applications. The seeds have been found to be an alternative source of commercial gums. The present investigation deals with isolation, purification and characterization of galactomannans from the seeds of Senna tora (S. tora). The galactomannan extraction was based on mechanical separation of the endosperm, water dissolution, centrifugation and precipitation with acetone. The polysaccharide obtained from S. tora seeds was characterized by using physicochemical and chromatographic procedures, as well as FTIR, Mass, (13)C NMR and (1)H NMR spectroscopy. The results indicated that the gum has the basic structure of galactomannans with a main chain of (1→4)-linked ß-D-mannopyranosyl units to which single α-(1→6)-D-linked galactopyranosyl units are attached through block pattern. The rheological studies indicated that the S. tora gum (1%, w/w) solution possesses pseudoplastic flow. The viscosity and other rheological properties confirmed its suitability as an excipient in the development of sustained release delivery systems.

Profiling the main cell wall polysaccharides of grapevine leaves using high-throughput and fractionation methods.

Vitis species include Vitis vinifera, the domesticated grapevine, used for wine and grape agricultural production and considered the world's most important fruit crop. A cell wall preparation, isolated from fully expanded photosynthetically active leaves, was fractionated via chemical and enzymatic reagents; and the various extracts obtained were assayed using high-throughput cell wall profiling tools according to a previously optimized and validated workflow. The bulk of the homogalacturonan-rich pectin present was efficiently extracted using CDTA treatment, whereas over half of the grapevine leaf cell wall consisted of vascular veins, comprised of xylans and cellulose. The main hemicellulose component was found to be xyloglucan and an enzymatic oligosaccharide fingerprinting approach was used to analyze the grapevine leaf xyloglucan fraction. When Paenibacillus sp. xyloglucanase was applied the main subunits released were XXFG and XLFG; whereas the less-specific Trichoderma reesei EGII was also able to release the XXXG motif as well as other oligomers likely of mannan and xylan origin. This latter enzyme would thus be useful to screen for xyloglucan, xylan and mannan-linked cell wall alterations in laboratory and field grapevine populations. This methodology is well-suited for high-throughput cell wall profiling of grapevine mutant and transgenic plants for investigating the range of biological processes, specifically plant disease studies and plant-pathogen interactions, where the cell wall plays a crucial role.