Structural characterization and therapeutic effect of Alhagi honey oligosaccharide on liver fibrosis in mice.

Alhagi honey is derived from the secretory granules of Alhagi pseudoalhagi Desv., a leguminous plant commonly known as camelthorn. Modern medical research has demonstrated that the extract of Alhagi honey possesses regulatory properties for the gastrointestinal tract and immune system, as well as exerts anti-tumor, anti-oxidative, anti-inflammatory, anti-bacterial, and hepatoprotective effects. The aim of this study was to isolate and purify oligosaccharide monomers (referred to as Mel) from camelthorn and elucidate their structural characteristics. Subsequently, the impact of Mel on liver injury induced by carbon tetrachloride (CCl4) in mice was investigated. The analysis identified the isolated oligosaccharide monomer (α-D-Glcp-(1 â†’ 3)-ß-D-Fruf-(2 â†’ 1)-α-D-Glcp), with the molecular formula C18H32O16. In a mouse model of CCl4-induced liver fibrosis, Mel demonstrated significant therapeutic effects by attenuating the development of fibrosis. Moreover, it enhanced anti-oxidant enzyme activity (glutathione peroxidase and superoxide dismutase) in liver tissues, thereby reducing oxidative stress markers (malondialdehyde and reactive oxygen species). Mel also improved serum albumin levels, lowered liver enzyme activities (aspartate aminotransferase and alanine aminotransferase), and decreased inflammatory factors (tumor necrosis factor-alpha, interleukin-1 beta, and interleukin-6). Immunohistochemistry, immunofluorescence, and western blotting analyses confirmed the ability of Mel to downregulate hepatic stellate cell-specific markers (collagen type I alpha 1 chain, alpha-smooth muscle actin, transforming growth factor-beta 1. Non-targeted metabolomics analysis revealed the influence of Mel on metabolic pathways related to glutathione, niacin, pyrimidine, butyric acid, and amino acids. In conclusion, the results of our study highlight the promising potential of Mel, derived from Alhagi honey, as a viable candidate drug for treating liver fibrosis. This discovery offers a potentially advantageous option for individuals seeking natural and effective means to promote liver health.

Ameliorative Effect of Morinda Officinalis Oligosaccharides on LPS-Induced Acute Lung Injury.

Acute lung injury (ALI) is a disease characterized by extensive lung damage and rampant inflammation, with a high mortality rate and no effective treatments available. Morinda officinalis oligosaccharides (MOOs), derived from the root of the traditional Chinese medicinal herb Morinda officinalis, known for its immune-boosting properties, presents a novel therapeutic possibility. To date, the impact of MOOs on ALI has not been explored. Our study aimed to investigate the potential protective effects of MOOs against ALI and to uncover the underlying mechanisms through an integrated approach of network pharmacology, molecular docking, and experimental validation. We discovered that MOOs significantly mitigated the pathological damage and decreased the expression of pro-inflammatory cytokines in LPS-induced ALI in mice. Complementary in vitro studies further demonstrated that MOOs effectively attenuated the M1 polarization induced by LPS. Network pharmacology analysis identified HSP90AA1, HSP90AB1, and NF-κB as key overlapping targets within a protein-protein interaction (PPI) network. Furthermore, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses elucidated the biological processes and signaling pathways implicated in MOOs' therapeutic action on ALI. Subsequently, molecular docking affirmed the binding of MOOs to the active sites of these identified targets. Corroborating these findings, our in vivo and in vitro experiments consistently demonstrated that MOOs significantly inhibited the LPS-induced upregulation of HSP90 and NF-κB. Collectively, these findings suggest that MOOs confer protection against ALI through a multi-target, multi-pathway mechanism, offering a promising new therapeutic strategy to mitigate this severe pulmonary condition.

Chemical Fingerprint Analysis and Quantitative Analysis of Saccharides in Morindae Officinalis Radix by HPLC-ELSD.

A method based on high performance liquid chromatography with evaporative light scattering detection (HPLC-ELSD) was developed for the quantitative analysis of three active compounds and chemical fingerprint analyses of saccharides in Morindae officinalis radix. Ten batches of Morindae officinalis radix were collected from different plantations in the Guangdong region of China and used to establish the fingerprint. The samples were separated with a COSMOIL Sugar-D column (4.6 mm × 250 mm, 5 µm) by using gradient elution with water (A) and acetonitrile (B). In addition, Trapped-Ion-Mobility (tims) Time-Of-Flight (tims TOF) was used to identify saccharides of Morindae officinalis radix. Fingerprint chromatogram presented 26 common characteristic peaks in the roots of Morinda officinalis How, and the similarities were more than 0.926. In quantitative analysis, the three compounds showed good regression (r = 0.9995-0.9998) within the test ranges, and the recoveries of the method were in the range of 96.7-101.7%. The contents of sucrose, kestose and nystose in all samples were determined as 1.21-7.92%, 1.02-3.37%, and 2.38-6.55%, respectively. The developed HPLC fingerprint method is reliable and was validated for the quality control and identification of Morindae officinalis radix and can be successfully used to assess the quality of Morindae officinalis radix.

Enzymatic extraction of pectic oligosaccharides from finger citron (Citrus medica L. var. sarcodactylis Swingle) pomace with antioxidant potential.

Finger citron pomace is a cheap and renewable by-product of the citrus processing industry, representing up to 60% of the fruit biomass. In this study, a pectinase-based and ultrasonic-assisted method was firstly used to extract pectic oligosaccharides (POS) from finger citron pomace. Using the orthogonal experiment design (OED), the maximum conversion rate of up to 64.5% from pomace to POS was obtained under the extraction conditions of 0.25 mg mL-1 pectinase and 50 mg mL-1 pectin at 45 °C and pH 4.5 for 2 h. The extracted POS was then fractionated and purified to homogeneous oligosaccharides (FCPOS-1) with a molecular weight of 2.15 kDa, and the analyses of monosaccharide composition, FTIR, NMR and ESI-MS indicated that FCPOS-1 consisted of GalA and a small amount of mannose, galactose and arabinose. Multiple antioxidant activity assays in vitro revealed that FCPOS-1 possessed remarkable antioxidant properties, especially scavenging activity against DPPH radicals up to 94.07%. FCPOS-1 has the potential to be an effective natural antioxidant for applications in the food and pharmaceutical industries.

A method for quantitative characterization of incomplete degradation products of polygalacturonic acid.

Biological activity of incomplete degradation products of polygalacturonic acid (IDPP) is closely related to its molecular weight and molecular weight distribution. Therefore, it is necessary to provide a reliable quantitative characterization method for evaluating these types of bioproducts. A novel method was established in this work for the quantitative characterization of IDPP based upon ethanol fractional precipitation. IDPP was fractionated into several fractions with high recovery (>95%), and the average molecular weights of each fraction was in descending order with the increase of ethanol concentration. Oligosaccharides (polymerization degree: 2-20) could be effectively harvested from the polygalacturonic acid enzymatic hydrolysate by ethanol precipitation. Moreover, the developed method had good repeatability and could also be applied to quantify enzymatic hydrolysis products of citrus-derived pectin polysaccharides. In conclusion, this paper provides a simple, accurate method for the quantitative characterization of IDPP and a strategy for the extraction of oligosaccharides.

Valorisation of walnut shell and pea pod as novel sources for the production of xylooligosaccharides.

According to the high interest in agro-industrial waste reutilisation, underutilised lignocellulosic materials, such as walnut shell (WS) and pea pod (PP), come in focus. The aim of this paper was to evaluate WS and PP as sources for the production of xylooligosaccharides (XOS). Hemicelluloses from WS and PP were recovered by combining varying parameters of delignification and alkaline extraction. At optimal recovery conditions, the fractions were further hydrolysed to XOS using GH11 endo-xylanase, by varying time and enzyme concentration. Xylose was predominant in the monomeric composition of the obtained hemicelluloses, building low-branched (arabino)glucuronoxylan, in WS exclusively, while in PP some xyloglucan as well. Delignification was essential for high recovery of total xylose from the materials, up to at least 70 %. High xylan conversions were obtained for 24 h hydrolysis, resulting in xylobiose and xylotriose when using low enzyme concentration, while in xylose and xylobiose with high enzyme concentration.

Oligosaccharides from Traditional Chinese Herbal Medicines: A Review of Chemical Diversity and Biological Activities.

Most of traditional Chinese herbal medicine (TCHM) substances come from medicinal plants, among which oligosaccharides have gradually attracted widespread attention at home and abroad due to their important biological activities and great medicinal potential. Numerous in vitro and in vivo experiments exhibited that oligosaccharides possess various activities, such as antitumor, anti-oxidation, modulate the gut microflora, anti-inflammatory, anti-infection, and immune-regulatory activities. Generally, biological activities are closely related to chemical structures, including molecular weight, monosaccharide composition, glycosidic bond connection, etc. The structural analysis of oligosaccharides is an important basis for studying their structure-activity relationship, but the structural diversity and complexity of carbohydrate compounds limit the study of oligosaccharides activities. Understanding the structures and biological functions of oligosaccharides is important for the development of new bioactive substances with natural oligosaccharides. This review provides a systematic introduction of the current knowledge of the chemical structures and biological activities of oligosaccharides. Most importantly, the reported chemical characteristics and biological activities of the famous TCHM oligosaccharides were briefly summarized, including Morinda officinalis, Rehmannia glutinosa, Arctium lappa, Polygala tenuifolia, Panax ginseng, Lycium barbarum and Astragalus membranaceus. TCHM oligosaccharides play an important role in nutrition, health care, disease diagnosis and prevention as well as have broad application prospects in the field of medicine.

Artichoke pectic oligosaccharide characterisation and virtual screening of prebiotic properties using in silico colonic fermentation.

The aim of this work was to develop a comprehensive workflow to elucidate molecular features of artichoke pectic oligosaccharides (POS) contributing to high potential prebiotic activity. First, obtainment of artichoke POS by Pectinex® Ultra-Olio was optimised using an artificial neural network. Under optimal conditions (pH 6.86; 1.5 h; enzyme dose 520.5 U/g pectin) POS yield was 624 mg/g pectin. Oligosaccharide structures (Mw < 1.3 kDa) were characterised by MALDI-TOF-MS. Then, conformational analysis of glycosidic bonds was performed by replica exchange molecular dynamics simulations and interaction mechanisms between POS and several microbial glycosidases were proposed by molecular modelling. Chemical information was integrated in virtual simulations of colonic fermentation. Highest hydrolysis rate was obtained for GalA-Rha-GalA trisaccharide, while the presence of partial negative charges and high radius of gyration enhance short chain fatty acid formation in distal colon. Established structure-activity relationships could help the rational design of prebiotics and clinical trials.

Oligosaccharides from Polygonatum Cyrtonema Hua: Structural characterization and treatment of LPS-induced peritonitis in mice.

Fructooligosaccharide was isolated from Polygonatum Cyrtonema Hua (PFOS) for the first time. Structure characterized using FT-IR, MALDI-TOF-MS, NMR, AFM, and TEM, indicated that PFOS was graminan-type fructan with a degree of polymerization ranging from 5 to 10. A murine model of lipopolysaccharide (LPS)-induced peritonitis was used to evaluate the in vivo anti-inflammatory and lung protective efficacy of PFOS. The result shown that pretreatment with PFOS (1.0 mg/mL) in peritonitis-induced mice could significantly inhibit the level of pro-inflammatory cytokines (TNF-α, IL-1ß) in serum (P < 0.001), increase mice survival rate from 12.5 % to 54 % (P < 0.05), and alleviated lung injury through ameliorating the damage of the pulmonary cellular architecture and reducing inflammatory monocyte accumulation in lung tissue. This effect of oligosaccharides could explain the traditional usage of P. cyrtonema as a tonic medicine for respiratory problems and it could be used as a potential natural ingredient with anti-inflammatory activity.

The heteropolysaccharide of Mangifera indica fruit: Isolation, chemical profile, complexation with ß-lactoglobulin and antioxidant activity.

A 91 kDa heteropolysaccharide (F2) was isolated from Mangifera indica fruit via extraction with H2O, purification by C2H5OH, starch removal and ion exchange chromatography. This polymer was made up mostly of Ara, Gal, Glc, Rha, Xyl, and GalA in a 37: 29: 9:3:2:19 molar proportion. It inherited a small backbone containing GalpA and Rhap units substituted with very large side chains containing differently linked Ara and Gal units plus esterified gallic acid (GA) residue. Several enzymes generated oligosaccharides including (i) Ara2-10Ac6-22, (ii) Gal1-8Ac5-26 and (iii) GA1Gal1Ac7 were characterized. This polysaccharide, which showed dose dependent antioxidant activity, exhibited synergism with gallic acid, and formed a complex (K = 1.2 × 106 M-1) with ß-lactoglobulin. Accordingly, H2O treatment produces a polysaccharide with desired biochemical properties; this could be effective in designing innovative functional food with flexible makeup.

Oligosaccharides composition of Descurainiae sophia exerts anti-heart failure by improving heart function and water-liquid metabolism in rats with heart failure.

PURPOSE: To investigate the protective effect of Oligosaccharides composition of Descurainiae sophia on doxorubicin-induced heart failure in rats, and to study its mechanism. METHOD: A rat model of heart failure was established in 180-220 g male Sprague-Dawley rats by low-dose intraperitoneal injection of doxorubicin for 6 weeks. Four weeks after continuous administration, echocardiography was used to detect left ventricular end diastolic diameter (LVEDD) and end systolic diameter (LVESD) in each group, and left ventricular short axis shortening rate (LVFS) and ejection fraction (LVEF) were calculated. ELISA method was used to detecte the levels of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), troponin I (cTnI), creatine kinase (CK), angiotensin II (Ang II), aldosterone (ALD), arginine pressurization AVP, Renin, Endothelin (ET-1), Nitric Oxide (NO), AQP2 in urine. 6 h cumulative urine output was measured by metabolic cage method after administration for 3 weeks. The urine osmotic pressure was measured by freezing point method. The expression of AQP2 protein in kidney was detected by Western blot method. The changes of myocardial morphology were observed. RESULTS: Compared with the normal control group, the heart rate of the model group was significantly increased (P < 0.01). LVESD and LVEDD were significantly increased (P < 0.01), LVEF and LVFS were significantly decreased (P < 0.01). The levels of CK, cTnI, NO, ET-1, BNP, ANP, ALD, AngII, Renin, AQP2, AVP and osmotic pressure were significantly increased (P < 0.01). Urine output was significantly decreased (P < 0.01). The heart HE showed obvious lesions. Compared with the model group, the Oligosaccharides composition of Descurainiae sophia significantly reduced the heart rate (P < 0.05), decreased LVESD and LVEDD (P < 0.01 or P < 0.05), and increased LVFS and LVEF values (P < 0.01). Oligosaccharides composition of Descurainiae sophia could significantly improve pathological damage of the heart, decrease the levels of cTnI, BNP, AngII, ALD, Renin, AVP in the serum, osmotic pressure and AQP2in the urine (P < 0.01 or P < 0.05), down-regulate the expression of AQP2 protein in the renal(P < 0.01), increase urine volume (P < 0.05). CONCLUSION: Oligosaccharides composition of Descurainiae sophia can significantly improve cardiac function and the disorder of water metabolism in rats with heart failure. Oligosaccharides composition of Descurainiae sophia exerts anti- heart failure through the RAAS system and the arginine vasopressin system.

Comparison of enzymatic and microwave-assisted alkaline extraction approaches for the generation of oligosaccharides from American Cranberry (Vaccinium macrocarpon) Pomace.

Cranberry pomace obtained from industrial juice production was characterized by proximate composition analysis and monosaccharide profile of the dietary fiber. Extraction of carbohydrates from pomace was investigated using microwave-assisted alkaline method and five commercial biocatalysts (pure endo-galactanase and four multienzyme biocatalysts). The extracts obtained from microwave-assisted approach had average total sugars yield of 21.3% and contained mostly oligosaccharides in the degree of polymerization range of 7 to 10. All multienzyme biocatalysts led to yields similar or higher than microwave-assisted approach (23.4% to 42.0%), but mainly generated shorter oligosaccharides with a degree of polymerization of 2 to 5. Compared to cranberry pomace dietary fiber, microwave-assisted extracts were enriched in pectic oligosaccharides, whereas the enzymatic extracts were enriched in glucans and had less rhamnose and galactose. Pomace ground for 5 min or more by ball mill assumed a powdery consistence. Longer milling did not affect particle size but increased their roughness. Such physical changes had no effect on the efficiency of multienzymatic treatment. PRACTICAL APPLICATION: The increased production of cranberries and cranberry products will continuously generate more pomace, a potentially valuable material for the generation of added-value products. Up to 60% to 70% of cranberry pomace is composed of plant cell wall material. The properties of naturally occurring plant cell wall polysaccharides and their corresponding oligosaccharides have been of a great interest, and many of them find application as functional food ingredients. Despite the fact that the cranberry pomace is rich in plant cell polysaccharides, it has been mainly explored as a source of phenolic antioxidants. This study reveals the efficiency of cranberry pomace as a source of nondigestible oligosaccharides. The use of microwave-assisted extraction and different biocatalysts for the enzymatic extraction led to oligosaccharides with well-defined monosaccharide composition and molecular weight distribution. The study of the effects of these extraction techniques on the yield and the characteristics of generated oligosaccharides would allow the modulation of their properties. As an overall, the findings of this study would contribute to lay the scientific ground for the development of innovative process for the isolation of nondigestible oligosaccharides as functional ingredients from cranberry pomace by products.

Bletilla striata oligosaccharides improve metabolic syndrome through modulation of gut microbiota and intestinal metabolites in high fat diet-fed mice.

As traditional Chinese medicine, Bletilla striata has been widely applied to clinical treatment for its unique pharmacological profiles. This study aimed to investigate the beneficial role of Bletilla striata oligosaccharides (BO) in improving the metabolic syndrome by regulation of gut microbiota and intestinal metabolites. Treatment of HFD-fed mice with BO prevented weight gain, reversed the glucose intolerance and insulin resistance, and inhibited adipocyte hypertrophy. BO-treated mice also suppressed chronic inflammation and protected intestinal barrier from damage. These effects were linked to the reversal of gut microbiota dysbiosis, which contributed to the homeostasis of intestinal metabolites including bile acids, short-chain fatty acids and tryptophan catabolites. The depletion and reconstitution of intestinal flora from BO- or HFD-treated mice confirmed the significance of gut microbiota in regulation of HFD-induced metabolic disorders. We demonstrated for the first time that BO improved metabolic syndrome through the regulation of gut microbiota and intestinal metabolites. The modulation initiated by BO represents a promising strategy for treatment of obesity and related metabolic diseases.

Characterization and anti-diabetic effects of the oligosaccharide fraction isolated from Rosa canina in STZ-Induced diabetic rats.

Diabetes mellitus is the most common metabolic disorder characterized by chronic hyperglycemia. There has been a surge of research studies aiming to use natural products in the management of diabetes. The objective of this study was to isolate and characterize the structure and anti-diabetic mechanisms of the main ingredient from Rosa canina. The oligosaccharide was isolated from Rosa canina fruits and characterized by a combination of FTIR, NMR and Mass spectrometry. Wistar rats were divided into negative control, diabetic (type 2), isolated oligosaccharide (IO)-treated diabetic and positive diabetic controls. Oral glucose tolerance, gluconeogenesis and α-glucosidase inhibitory tests as well as immunohistochemistry and quantitative real time-PCR were performed to elucidate the molecular anti-diabetic mechanisms of IO. Structural analyses confirmed the oligosaccharide structure of isolated fraction. Gluconeogenesis and α-glucosidase activity were inhibited by IO in diabetic rats. The oral glucose tolerance test was improved significantly in the group treated with the IO (P < 0.05). Pancreatic ß-cells and tissue pathological examination showed a significant improvement after the treatment period. In addition, the expression of Ngn3, Nkx6.1 and insulin increased in oligosaccharide-treated compared to untreated diabetic rats. Owing to the verified anti-diabetic effects and regenerative potential, isolated oligosaccharide could be considered as the promising drug in the management of diabetes.

Inducing type 2 immune response, induction of angiogenesis, and anti-bacterial and anti-inflammatory properties make Lacto-n-Neotetraose (LNnT) a therapeutic choice to accelerate the wound healing process.

The healing process of non-healing and full-thickness wounds is currently facing some serious challenges. In such ulcers, losing a large part of skin causes a chronic infection due to the entrance of various pathogens in the wound bed. Moreover, poor vascularization, uncontrolled inflammation, and delayed re-epithelialization increase the healing time in patients suffering from such wounds. In this light, tissue engineering provides a wide range of strategies using a variety of biomaterials, biofactors and stem cells to decrease the healing time and restore the function of the damaged site. A suitable wound healing agent should possess some critical parameters such as inducing re-epithelialization, anti-inflammatory and anti-bacterial properties, and angiogenic capability. The Lacto-n-Neotetraose (LNnT) with chemical formula C26H45NO21 is an oligosaccharide present in human milk and soluble antigens extracted from Schistosoma mansoni eggs. It is reported that LNnT induces type 2 immune response (Th2 immunity). Th2 immunity promotes re-epithelialization, angiogenesis and wound contraction by recruiting the cells which produce Th2-related cytokines. Moreover, LNnT shows some special characteristics such as angiogenic capability, anti-inflammatory, and anti-bacterial effects which can address the mentioned challenges in the treatment of non-healing and full-thickness wounds. Here, we hypothesize that utilizing LNnT is an appropriate biofactor which would improve the healing process in full-thickness and non-healing wounds.

Oligosaccharide and glucose esters from the roots of Polygala arillata.

The root of plant Polygala arillata has been used in the Oriental medicine as a tonic and for the treatment of certain diseases. Our current research on phytochemical profile of the roots of P. arillata led to the isolation of a new oligosaccharide ester (1, polygaloside), a new glucose ester (7, arillatoside), along with five known sucrose esters (2-6). Their structures were elucidated on the basis of extensive chemical and spectroscopic methods as well as comparison with those reported in the literature. The occurence of various oligosaccharide esters in P. arillata including unique compounds plays taxonomical impact and suggests potential in medicinal uses of the title plant.

Anticariogenic Activity of Agarobiose and Agarooligosaccharides Derived from Red Macroalgae.

3,6-Anhydro-l-galactose (AHG) produced from agarose in red macroalgae was recently suggested as an anticariogenic sugar to replace widely used xylitol. However, the multi-step process for obtaining monomeric sugar AHG from agarose may be expensive. Generally, it is easier to obtain oligosaccharides than monosaccharides from polysaccharides. Therefore, a one-step process to obtain agarobiose (AB) from agarose was recently developed, and here, we suggest AB as a new anticariogenic agent, owing to its anticariogenic activity against Streptococcus mutans. Among AHG-containing oligosaccharides, AB, neoagarobiose (NAB), agarooligosaccharides (AOSs), and neoagarooligosaccharides (NAOSs), AB showed higher inhibitory activity than AOSs against the growth and lactic acid production of S. mutans; no such inhibitory activity was observed for NAB and NAOSs. This inhibitory effect of AB was comparable to the previously reported inhibitory activity of AHG against S. mutans. These results suggest that AB, which can be more economically and simply produced than AHG, may serve as an anticariogenic sugar.

Anti-diabetic effect of oligosaccharides from seaweed Sargassum confusum via JNK-IRS1/PI3K signalling pathways and regulation of gut microbiota.

Brown seaweed Sargassum confusum (C. Agardh) has been used in traditional Chinese medicine to treat a variety of diseases. The aim of the present study was to evaluate the anti-diabetic effect of oligosaccharides from brown seaweed S. confusum (SCO). The anti-diabetic effect of SCO was evaluated in vivo using high-fat/high-sucrose fed hamsters. Molecular mechanisms of modulating gene expression of specific members of insulin signaling pathways were determined. The components of the intestinal microflora in diabetic animals were also analyzed by high-throughput 16S rRNA gene sequencing. And it was found that SCO had a sequence of sulfated anhydrogalactose and methyl sulfated galactoside units. Fasting blood glucose levels were significantly decreased after SCO administration. Histology showed that SCO could protect the cellular architecture of the liver. SCO could also significantly increase the relative abundance of Lactobacillus and Clostridium XIVa and decrease that of Allobaculum, Bacteroides and Clostridium IV. The active role of SCO in anti-diabetic effect was revealed by its regulation of insulin receptor substrate 1/phosphatidylinositol 3-kinase and c-Jun N-terminal kinase pathways. These results suggested that SCO might be used as a functional material to regulate gut microbiota in obese and diabetic individuals.

Purification, Characterization, Prebiotic Preparations and Antioxidant Activity of Oligosaccharides from Mulberries.

A water-soluble oligosaccharide termed EMOS-1a was prepared by enzymatic hydrolysis of polysaccharides purified from mulberries by column chromatography. The chemical structure of the purified fraction was investigated by ultraviolet spectroscopy, Fourier-transform infrared spectroscopy, and gas chromatography-mass spectrometry, which indicated that galactose was the main constituent of EMOS-1a. Chemical analyses showed that the uronic acid and sulfate content of EMOS-1a were 5.6% and 8.35%, respectively, while gel permeation chromatography showed that EMOS-1a had an average molecular weight of 987 Da. The antioxidant activities of EMOS-1a were next investigated, and EMOS-1a exhibited concentration-dependent 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity, Trolox equivalent antioxidant capacity, and ferric reducing antioxidant power. The level of proliferation of Lactobacillus rhamnosus reached 1420 ± 16% when 4% (w/v) EMOS-1a was added, where the number of colonies in MRS (de Man, Rogosa, and Sharpe) medium with no added oligosaccharide was defined as 100% proliferation. These results indicate that the oligosaccharide EMOS-1a could be used as a natural antioxidant in prebiotic preparations.

Pectin oligosaccharides from fruit of Actinidia arguta: Structure-activity relationship of prebiotic and antiglycation potentials.

Pectin oligosaccharides (POSs) have prebiotic and antiglycation activities in vitro, but the specific structure-activity relationship is unclear. In this study, POSs were obtained by enzymatic and ultrasound-assisted enzymatic degradation of pectin polysaccharide (PPS), respectively. Based on the chemical characterization, the antiglycation in vitro and prebiotic activities of POSs were compared and the structure-activity relationship was studied. The results showed that the antiglycation activity of POSs in vitro was proportional to the galacturonic acid content and GalA:Rha molar ratios except for the low molecular weight POSs (LM-POSs), and inversely proportional to its branching degree, such as Ara:Rha and Gal:Rha molar ratios. In addition, it was also found that the prebiotic activity of POSs was positively correlated with Ara:Rha and Gal:Rha molar ratios in molecule composition and the neutral sugar content, especially galactose and arabinose. The degree of esterification (DE) was less important for both antiglycation and prebiotic activity of POSs. These results provided an important theoretical basis for POSs application in food.