Isolation and characterization of feruloylated oligosaccharides from Phyllostachys acuta and in vitro antioxidant activity.

Feruloylated oligosaccharides (FOs) generated by decomposing plant hemicellulose, offer a wide range of potential applications in both the food and biomedical areas. As a graminaceous plant, bamboo is rich in hemicellulose. However, the structural composition and activity studies of FOs from it were rarely reported. In this study, FOs from Phyllostachys acuta (pFOs) obtained by enzymatic hydrolysis were isolated by AmberliteXAD-2 and C18 SPE columns. Then, pFOs were qualitatively and quantitatively analyzed by UPLC-ESI-MS/MS after labeled by 3-Amino-9-ethyl-carbazole (AEC), and the chemical antioxidant activity of pFOs and effects of pFOs on H2O2-induced oxidative damage were investigated. Finally, 14 of pFOs isomers were distinguished and identified, of which 10 did not contain hexoses and 4 did, and the three most abundant pFO structures were 12 (Iso 7, F1A1X2H2-AEC, 29.04 %), 11 (Iso 6, F1A1X1H2-AEC, 17.96 %), and 4 (Iso 3-1, F1A1X3-AEC, 15.57 %). The results of antioxidant studies showed that pFOs possessed certain reducing power, scavenging DPPH radicals, scavenging superoxide anion radicals, and scavenging hydroxyl radicals. Among them, the ability to clear DPPH radicals was particularly significant. pFOs significantly reduced the viability of RAW264.7 cells after H2O2 induction, whereas pFOs had a significant protective effect (p < 0.001). pFOs increased the viability of T-AOC and SOD enzymes in oxidatively damaged cells, as well as had a significant inhibition effect on ROS elevation (p < 0.001). This study lays the foundation for the structural analysis and antioxidant activity evaluation of bamboo-derived feruloyl oligosaccharides for their application in food and pharmaceutical fields.

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.

Pressurized Hot Water Extraction and Bio-Hydrogels Formulation with Aristotelia chilensis [Mol.] Stuntz Leaves.

Aristotelia chilensis is a plant rich in phenolics and other bioactive compounds. Their leaves are discarded as waste in the maqui berry industry. A new application of these wastes is intended by the recovery of bioactive compounds using pressurized hot water extraction with conventional or microwave heating. Both technologies have been selected for their green character regarding the type of solvent and the high efficiency in shorter operation times. Extractions were performed in the temperature range 140-200 °C with a solid/liquid ratio of 1:15 (w:w). The extracts' total phenolic content, antioxidant capacity, and saccharides content obtained with both heating methods were measured. Additionally, the thermo-rheological properties of the gelling matrix enriched with these extracts were analyzed. Optimum conditions for lyophilized extracts were found with conventional heating, at 140 °C and 20 min extraction; 250.0 mg GAE/g dry extract and 1321.5 mg Trolox/g dry extract. Close to optimum performance was achieved with microwave heating in a fraction of the time (5 min) at 160 °C (extraction), yielding extracts with 231.9 mg GAE/g dry extract of total phenolics and antiradical capacity equivalent to 1176.3 mg Trolox/g dry extract. Slightly higher antioxidant values were identified for spray-dried extracts (between 5% for phenolic content and 2.5% for antioxidant capacity). The extracts obtained with both heating methods at 200 °C contained more than 20% oligosaccharides, primarily glucose. All the formulated gelling matrices enriched with the obtained extracts displayed intermediate gel strength properties. The tested technologies efficiently recovered highly active antioxidant extracts, rich in polyphenolics, and valuable for formulating gelling matrices with potential applicability in foods and other products.

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.

Alginate derived functional oligosaccharides: Recent developments, barriers, and future outlooks.

Alginate is a biopolymer used extensively in the food, pharmaceutical, and chemical industries. Alginate oligosaccharides (AOS) derived from alginate exhibit superior biological activities and therapeutic potential. Alginate lyases with characteristic substrate specificity can facilitate the production of a broad array of AOS with precise structure and functionality. By adopting innovative analytical tools in conjunction with focused clinical studies, the structure-bioactivity relationship of a number of AOS has been brought to light. This review covers fundamental aspects and recent developments in AOS research. Enzymatic and microbial processes involved in AOS production from brown algae and sequential steps involved in AOS structure elucidation are outlined. Biological mechanisms underlying the health benefits of AOS and their potential industrial and therapeutic applications are elaborated. Withal, various challenges in AOS research are traced out, and future directions, specifically on recombinant systems for AOS preparation, are delineated to further widen the horizon of these exceptional oligosaccharides.

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.

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.

Structural analysis of the core oligosaccharides from Fusobacterium nucleatum lipopolysaccharides.

Fusobacterium nucleatum is a gram-negative bacterium, part of the normal human microflora. It is associated with various health complications, including periodontitis and colorectal cancer. Its surface is covered with lipopolysaccharide, which interacts with the immune system and can be involved in various processes in health and disease conditions. Here we present the results of structural analysis of core oligosaccharides from the lipopolysaccharides of several strains of F. nucleatum. Pure compounds were isolated using mild acid hydrolysis or alkaline deacylation of the lipopolysaccharides and analyzed by NMR spectroscopy, mass-spectrometry and chemical methods. All cores analyzed had a common octasaccharide region, including five heptose residues and a non-phosphorylated 3-deoxy-d-manno-oct-2-ulosonic acid residue. The common region is substituted with different additional components specific for each strain. By structure type the F. nucleatum core is similar to that produced by Aeromonas.

Induction of Natural Defenses in Tomato Seedlings by Using Alginate and Oligoalginates Derivatives Extracted from Moroccan Brown Algae.

Polysaccharides extracted from marine algae have attracted much attention due to their biotechnological applications, including therapeutics, cosmetics, and mainly in agriculture and horticulture as biostimulants, biofertilizers, and stimulators of the natural defenses of plants. This study aimed to evaluate the ability of alginate isolated from Bifurcaria bifurcata from the Moroccan coast and oligoalginates derivatives to stimulate the natural defenses of tomato seedlings. Elicitation was carried out by the internodal injection of bioelicitor solutions. The elicitor capacities were evaluated by monitoring the activity of phenylalanine ammonia-lyase (PAL) as well as polyphenols content in the leaves located above the elicitation site for 5 days. Alginate and oligoalginates treatments triggered plant defense responses, which showed their capacity to significantly induce the PAL activity and phenolic compounds accumulation in the leaves of tomato seedlings. Elicitation by alginates and oligoalginates showed an intensive induction of PAL activity, increasing from 12 h of treatment and remaining at high levels throughout the period of treatment. The amount of polyphenols in the leaves was increased rapidly and strongly from 12 h of elicitation by both saccharide solutions, representing peaks value after 24 h of application. Oligoalginates exhibited an effective elicitor capacity in polyphenols accumulation compared to alginate polymers. The alginate and oligosaccharides derivatives revealed a similar elicitor capacity in PAL activity whereas the accumulation of phenolic compounds showed a differential effect. Polysaccharides extracted from the brown seaweed Bifurcaria bifurcate and oligosaccharides derivatives induced significantly the phenylpropanoid metabolism in tomato seedlings. These results contribute to the valorization of marine biomass as a potential bioresource for plant protection against phytopathogens in the context of eco-sustainable green technology.

Extraction, characterization of xylan from Azadirachta indica (neem) sawdust and production of antiproliferative xylooligosaccharides.

Xylan extracted from neem sawdust gave 22.5%, (w/w) yield. The extracted xylan was composed of xylose and glucuronic acid at a molar ratio of 8:1 and with a molecular mass, ~66 kDa. FTIR and NMR analyses indicated a backbone of xylan substituted with 4-O-methyl glucuronic acid at the O-2 position. FESEM analysis showed a highly porous and granular surface structure of xylan. A thermogravimetric study of xylan showed thermal denaturation at 271 °C. The hydrolysis of xylan by recombinant endo-ß-1,4-xylanase produced a mixture of xylooligosaccharides ranging from degree of polymerization 2-7. Xylooligosaccharides inhibited cell growth of human colorectal cancer (HT-29) cells but did not affect the mouse fibroblast cells confirming its biocompatibility. Western blotting, DNA laddering and flow cytometric analysis displayed inhibition of HT-29 cells by xylooligosaccharides. FLICA staining and mitochondrial membrane potential analyses confirmed the activation of the intrinsic pathway of apoptosis. The study amply indicated that the xylooligosaccharides produced from neem xylan could be potentially used as an antiproliferative agent.

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.

Chitosan Oligosaccharides Attenuate Amyloid Formation of hIAPP and Protect Pancreatic ß-Cells from Cytotoxicity.

The deposition of aggregated human islet amyloid polypeptide (hIAPP) in the pancreas, that has been associated with ß-cell dysfunction, is one of the common pathological features of patients with type 2 diabetes (T2D). Therefore, hIAPP aggregation inhibitors hold a promising therapeutic schedule for T2D. Chitosan oligosaccharides (COS) have been reported to exhibit a potential antidiabetic effect, but the function of COS on hIAPP amyloid formation remains elusive. Here, we show that COS inhibited the aggregation of hIAPP and disassembled preformed hIAPP fibrils in a dose-dependent manner by thioflavin T fluorescence assay, circular dichroism spectroscopy, and transmission electron microscope. Furthermore, COS protected mouse ß-cells from cytotoxicity of amyloidogenic hIAPP, as well as apoptosis and cycle arrest. There was no direct binding of COS and hIAPP, as revealed by surface plasmon resonance analysis. In addition, both chitin-oligosaccharide and the acetylated monosaccharide of COS and glucosamine had no inhibition effect on hIAPP amyloid formation. It is presumed that, mechanistically, COS regulate hIAPP amyloid formation relating to the positive charge and degree of polymerization. These findings highlight the potential role of COS as inhibitors of hIAPP amyloid formation and provide a new insight into the mechanism of COS against diabetes.

Optimation for preparation of oligosaccharides from flaxseed gum and evaluation of antioxidant and antitumor activities in vitro.

Flaxseed oligosaccharides (FGOS) were prepared by degradation of flaxseed gum (FG) using enzymatic method. Factors affecting the enzymatic hydrolysis of FG were investigated by single factor and orthogonal tests. In the optimum hydrolysis conditions (reaction time 12 h, temperature 50 °C, pH 4.5, cellulase concentration 100 U/mL), the reducing sugar ratio and extraction yield of FGOS were 33.6 ± 0.35% and 56.8 ± 0.41%, respectively. The average molecular weight of FGOS was about 1.6 kDa, which consists of mannose, galactose, glucose, arabinose, glucuronic acid, xylose, rhamnose, ribose, galacturonic acid. Fourier-transform infrared spectra and NMR indicated that FG was successfully degraded to FGOS. FGOS exhibited better antioxidant activities than FG on scavenging hydroxyl, ABTS and DPPH radicals. In vitro cytotoxicities experiments reveal FGOS acquire the ability of antiproliferation against HepG2 and Hela cells in a dose-dependent manner.

Salivary N-glycosylation as a biomarker of oral cancer: A pilot study.

Reliable biomarkers for oral cancer (OC) remain scarce, and routine tests for the detection of precancerous lesions are not routine in the clinical setting. This study addresses a current unmet need for more sensitive and quantitative tools for the management of OC. Whole saliva was used to identify and characterize the nature of glycans present in saliva and determine their potential as OC biomarkers. Proteins obtained from whole saliva were subjected to PNGase F enzymatic digestion. The resulting N-glycans were analyzed with weak anion exchange chromatography, exoglycosidase digestions coupled to ultra-high performance liquid chromatography and/or mass spectrometry. To determine N-glycan changes, 23 individuals with or without cancerous oral lesions were analyzed using Hydrophilic interaction ultra performance liquid chromatography (HILIC-UPLC), and peak-based area relative quantitation was performed. An abundant and complex salivary N-glycomic profile was identified. The main structures present in saliva were neutral oligosaccharides consisting of high mannose, hybrid and complex structures, followed by smaller fractions of mono and di-sialylated structures. To determine if differential N-glycosylation patterns distinguish between OC and control groups, Mann-Whitney testing and principle component analysis (PCA) were used. Eleven peaks were shown to be statistically significant (P ≤ 0.05), while PCA analysis showed segregation of the two groups based on their glycan profile. N-glycosylation changes are active in the oral carcinogenic process and may serve as biomarkers for early detection to reduce morbidity and mortality. Identifying which N-glycans contribute most in the carcinogenic process may lead to their use in the detection, prognosis and treatment of OC.

Stilbene Glycoside Oligomers from the Roots of Polygonum multiflorum.

Five new trans-2,3,5,4'-tetrahydroxystilbene 2-O-ß-d-glucopyranoside (TSG)-based stilbene glycoside oligomers (1-5) were isolated from the roots of Polygonum multiflorum. Their structures were elucidated by comprehensive spectroscopic analyses and chemical evidences. The absolute configurations of 1, 2, 4, and 5 were established by quantum-chemical electronic circular dichroism (ECD) calculations. Putative biosynthetic pathways of 1-5 were proposed using TSG as the key precursor. In addition, compounds 1 (multiflorumiside H) and 3 (multiflorumiside J) exhibited moderate inhibitory activities against NO production in LPS-stimulated RAW264.7 cells.

Inulin with a low degree of polymerization protects human umbilical vein endothelial cells from hypoxia/reoxygenation-induced injury.

Here, we identified inulin-type oligosaccharides with 3-13 degrees of polymerization from Morinda officinalis. Radical-scavenging assays showed that Inulins 4-7 had modest anti-oxidative effects. Inulins 4 and 5 dose-dependently increased human umbilical vein endothelial cell survival during hypoxia/re-oxygenation (H/R)-induced injury, and Inulin 5 promoted angiogenesis. Triplicate assays with the Affymetrix Human Transcriptome Array 2.0 showed that Inulin 5 exposure up-regulated genes associated with cell cycle progression, apoptosis, DNA replication and repair, ubiquitin-mediated proteolysis, the mitogen-activated protein kinase pathway, and the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)-signaling pathway. Flow cytometry, reverse transcription-quantitative polymerase chain reaction, and western blot experiments verified the microarray results and demonstrated that Inulin 5 influenced cell cycle progression and the PI3K-protein kinase B (PKB)-endothelial nitric oxide synthase (eNOS) pathway. Thus, inulin-type oligosaccharides from M. officinalis roots may protect against H/R-induced injury, primarily through an anti-oxidative effect, and promote angiogenesis by activating the PI3K-PKB-eNOS-signaling pathway.

Bovine colostrum-driven modulation of intestinal epithelial cells for increased commensal colonisation.

Nutritional intake may influence the intestinal epithelial glycome and in turn the available attachment sites for bacteria. In this study, we tested the hypothesis that bovine colostrum may influence the intestinal cell surface and in turn the attachment of commensal organisms. Human HT-29 intestinal cells were exposed to a bovine colostrum fraction (BCF) rich in free oligosaccharides. The adherence of several commensal bacteria, comprising mainly bifidobacteria, to the intestinal cells was significantly enhanced (up to 52-fold) for all strains tested which spanned species that are found across the human lifespan. Importantly, the changes to the HT-29 cell surface did not support enhanced adhesion of the enteric pathogens tested. The gene expression profile of the HT-29 cells following treatment with the BCF was evaluated by microarray analysis. Many so called "glyco-genes" (glycosyltransferases and genes involved in the complex biosynthetic pathways of glycans) were found to be differentially regulated suggesting modulation of the enzymatic addition of sugars to glycoconjugate proteins. The microarray data was further validated by means of real-time PCR. The current findings provide an insight into how commensal microorganisms colonise the human gut and highlight the potential of colostrum and milk components as functional ingredients that can potentially increase commensal numbers in individuals with lower counts of health-promoting bacteria.

Antioxidant properties of feruloylated oligosaccharides of different degrees of polymerization from wheat bran.

In this study, four main components of feruloylated oligosaccharides (FOs),FOs-1, FOs-2, FOs-3 and FOs-4,were isolated from wheat bran by use of Amberlite XAD-2 and Sephadex LH-20. Structural characterization of FOs was determined by use of high performance liquid chromatography (HPLC), gas chromatography (GC) and fourier transform-infrared spectroscopy (FT-IR). Antioxidant properties were investigated in vitro. Average degrees of polymerization (DP) of the four components (FOs-1, FOs-2, FOs-3 and FOs-4) were approximately 10.6, 7.7, 6.1 and 3.4, respectively. In addition, DP were consistent with molar ratios of arabinose and xylose in 1:9.46, 1:5.30, 1:2.91 and 1:0.19, respectively. The presence of ß-glycosidic linkage was confirmed at 896 cm - 1 by use of FT-IR. In vitro antioxidant studies demonstrated that FOs-1, FOs-2, FOs-3 and FOs-4 possessed significant antioxidant activities in the dose-dependent manner. In addition, the degree of polymerization affected antioxidant capacity. These results have improved our understanding of the relationship between FOs with different structural types and their antioxidant activities.

Influence of Modified Fucoidan and Related Sulfated Oligosaccharides on Hematopoiesis in Cyclophosphamide-Induced Mice.

Immunosuppression derived after cytostatics application in cancer chemotherapy is considered as an adverse side effect that leads to deterioration of quality of life and risk of infectious diseases. A linear sulfated (1→3)-α-l-fucan M-Fuc prepared by chemical modification of a fucoidan isolated from the brown seaweed Chordaria flagelliformis, along with two structurally related synthetic sulfated oligosaccharides, were studied as stimulators of hematopoiesis on a model of cyclophosphamide immunosuppression in mice. Recombinant granulocyte colony-stimulating factor (r G-CSF), which is currently applied in medicine to treat low blood neutrophils, was used as a reference. Polysaccharide M-Fuc and sulfated difucoside DS did not demonstrate significant effect, while sulfated octasaccharide OS showed higher activity than r G-CSF, causing pronounced neutropoiesis stimulation. In addition, production of erythrocytes and platelets was enhanced after the octasaccharide administration. The assessment of populations of cells in blood and bone marrow of mice revealed the difference in mechanisms of action of OS and r G-CSF.

Oligosaccharides Derived from Red Seaweed: Production, Properties, and Potential Health and Cosmetic Applications.

Because of their potential use as functional ingredients in human nutrition, oligosaccharides derived from natural sources are receiving paramount consideration. Red seaweed, a proven rich source of agar and carrageenan, is one of the most abundantly present sources of such oligosaccharides. Agaro-oligosaccharides (AOS) and carrageenan-oligosaccharides (COS) are produced from agar and carrageenan, respectively, through chemical and enzymatic hydrolyses. Enzymatic hydrolysis of agar and carrageenan into oligosaccharides is preferred in industrial production because of certain problems associated with chemical hydrolysis, including the release of high amounts of monosaccharides and undesirable toxic products, such as furfural. AOS and COS possess many biological activities, including prebiotic, immuno-modulatory, anti-oxidant, and anti-tumor activities. These activities are related to their chemical structure, molecular weight, degree of polymerization, and the flexibility of the glycosidic linkages. Therefore, the structure⁻function relationship and the mechanisms occurring during the specific biological applications of AOS and COS are discussed herein. Moreover, the chromatographic separation, purification, and characterization of AOS and COS are also part of this review. This piece of writing strives to create a new perspective on the potential applications of AOS and COS in the functional food and pharmaceutical industry.