In situ visualization of the cellular uptake and sub-cellular distribution of mussel oligosaccharides

Unlike chemosynthetic drugs designed for specific molecular and disease targets,active small-molecule natural products typically have a wide range of bioactivities and multiple targets,necessitating extensive screening and development.To address this issue,we propose a strategy for the direct in situ microdynamic examination of potential drug candidates to rapidly identify their effects and mechanisms of action.As a proof-of-concept,we investigated the behavior of mussel oligosaccharide(MOS-1)by tracking the subcellular dynamics of fluorescently labeled MOS-1 in cultured cells.We recorded the entire dynamic process of the localization of fluorescein isothiocyanate(FITC)-MOS-1 to the lysosomes and visualized the distribution of the drug within the cell.Remarkably,lysosomes containing FITC-MOS-1 actively recruited lipid droplets,leading to fusion events and increased cellular lipid consumption.These drug behaviors confirmed MOS-1 is a candidate for the treatment of lipid-related diseases.Furthermore,in a high-fat HepG2 cell model and in high-fat diet-fed apolipoprotein E(ApoE)^(-/-)mice,MOS-1 significantly promoted triglyceride degradation,reduced lipid droplet accumulation,lowered serum triglyceride levels,and mitigated liver damage and steatosis.Overall,our work supports the prioritization of in situ visual monitoring of drug location and distribution in subcellular compartments during the drug development phase,as this methodology contributes to the rapid identification of drug indications.Collectively,this methodology is significant for the screening and development of selective small-molecule drugs,and is expected to expedite the identification of candidate molecules with medicinal effects.

Physiological and Transcriptome Analysis Illuminates the Molecular Mechanisms of the Drought Resistance Improved by Alginate Oligosaccharides in Triticum aestivum L.

Alginate oligosaccharides(AOS)enhance drought resistance in wheat(Triticum aestivum L.),but the definite mechanisms remain largely unknown.The physiological and transcriptome responses of wheat seedlings treated with AOS were analyzed under drought stress simulated with polyethylene glycol-6000.The results showed that AOS promoted the growth of wheat seedlings and reduced oxidative damage by improving peroxidase and superoxide dismutase activities under drought stress.A total of 10,064 and 15,208 differentially expressed unigenes(DEGs)obtained from the AOS treatment and control samples at 24 and 72 h after dehydration,respectively,were mainly enriched in the biosynthesis of secondary metabolites(phenylpropanoid biosynthesis,flavonoid biosynthesis),carbohydrate metabolism(starch and sucrose metabolism,carbon fixation in photosynthetic organisms),lipid metabolism(fatty acid elongation,biosynthesis of unsaturated fatty acids,alpha-linolenic acid metabolism,cutin,suberine and wax biosynthesis),and signaling transduction pathways.The up-regulated genes were related to,for example,chlorophyll a-b binding protein,amylosynthease,phosphotransferase,peroxidase,phenylalanine ammonia lyase,flavone synthase,glutathione synthetase.Signaling molecules(including MAPK,plant hormones,H_(2)O_(2) and calcium)and transcription factors(mainly including NAC,MYB,MYB-related,WRKY,bZIP family members)were involved in the AOS-induced wheat drought resistance.The results obtained in this study help underpin the mechanisms of wheat drought resistance improved by AOS,and provides a theoretical basis for the application of AOS as an environmentally sustainable biological method to improve drought resistance in agriculture.

Low fermentable oligosaccharides, disaccharides,monosaccharides, and polyols diet in children

Irritable bowel syndrome (IBS) is a lifelong condition with a high prevalence among children and adults. As the diet is a frequent factor that triggers the symptoms, it has been assumed that by avoiding the consumption of fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP), the symptoms might be improved. Therefore, in the past decade, low FODMAP diet has been intensively investigated in the management of IBS. The capacity of FODMAPs to trigger the symptoms in patients with IBS was related to the stimulation of mechanoreceptors in the small and large intestine. This stimulation appears as a response to a combination of increased luminal water (the osmotic effect) and the release of gases (carbon dioxide and hydrogen) due to the fermentation of oligosaccharides and malabsorption of fructose, lactose and polyols. Numerous studies have been published regarding the efficacy of a low FODMAP diet compared to a traditional diet in releasing the IBS symptoms in adults, but there are only a few studies in the juvenile population. The aim of this review is to analyze the current data on both low FODMAP diet in children with IBS and the effects on their nutritional status and physiological development, given the fact that it is a restrictive diet.

Therapeutic potential and mechanism of functional oligosaccharides in inflammatory bowel disease: a review

Inflammatory bowel disease(IBD)is characterized by recurrent attacks and long courses,and the number of patients has expanded rapidly year by year.Additionally,current conventional strategies exist serious adverse effects.In this case,it is an urgent issue to find out an effective and safe treatment.Functional oligosaccharides possess safe and excellent physiological activities,and have attracted enormous attention due to their great therapeutic potential for IBD.This review emphasizes the attenuating effects of distinct functional oligosaccharides on IBD and their structure,and summarizes the main mechanisms from the aspects of regulating intestinal fl ora structure,repairing intestinal barrier,modulating immune function and mediating related signaling pathways in order to reveal the relationship between functional oligosaccharides,immune regulation,intestinal epithelial cells,gut fl ora and IBD treatment.Oligosaccharides possess excellent protective effects on IBD,and can be considered as safe and functional ingredients in the health food and pharmaceutical industry.

Enzymatically prepared alginate oligosaccharides improve broiler chicken growth performance by modulating the gut microbiota and growth hormone signals

Background Alginate oligosaccharide(AOS)holds great potential as a novel feed supplement in farm animals.However,the effects of AOS on chicken health and the underlying mechanisms are not fully understood.This study aimed to optimize the enzymatic preparation of AOS by using bacterial alginate lyases expressed in yeast,investigate the effects of the prepared AOS on the growth performance and gut health of broiler chickens,and reveal the underlying mechanisms.Results Five alginate lyases from bacteria were cloned into Pichia pastoris GS115 and the alginate lyase PDE9 was expressed at relatively high yield,activity and stability in P.pastoris.Animal trials were carried out using 3201-day-old male Arbor Acres broilers(four groups;8 replicates/group×10 chicks/replicate)receiving either a basal diet or the same diet supplemented with 100,200 and 400 mg/kg PDE9-prepared AOS for 42 d.The results showed that dietary supplementation of 200 mg/kg AOS displayed the highest activity in promoting the birds’ADG and ADFI(P<0.05).AOS ameliorated the intestinal morphology,absorption function and barrier function,as indicated by the enhanced(P<0.05)intestinal villus height,maltase activity,and the expression of PEPT,SGLT1,ZNT1,and occludin.AOS also increased serum insulin-like growth factor-1,ghrelin(P<0.05),and growth hormone(P<0.1).Moreover,the concentrations of acetate,isobutyrate,isovalerate,valerate,and total SCFAs in cecum of birds fed AOS were significantly higher than the control birds(P<0.05).Metagenomic analysis indicated that AOS modulated the chicken gut microbiota structure,function,and microbial interactions and promoted the growth of SCFAs-producing bacteria,for example,Dorea sp.002160985;SCFAs,especially acetate,were found positively correlated with the chicken growth performance and growth-related hormone signals(P<0.05).We further verified that AOS can be utilized by Dorea sp.to grow and to produce acetate in vitro.Conclusions We demonstrated that the enzymatically produced AOS effectively promoted broiler chicken growth performance by modulating the chicken gut microbiota structure and function.For the first time,we established the connections among AOS,chicken gut microbiota/SCFAs,growth hormone signals and chicken growth performance.

Combinatorial Enzyme Approach to Convert Wheat Insoluble Arabinoxylan to Bioactive Oligosaccharides

Combinatorial enzyme technology was applied for the conversion of wheat insoluble arabinoxylan to oligosaccharide structural variants. The digestive products were fractionated by Bio-Gel P4 column and screened for bioactivity. One fraction pool was observed to exhibit antimicrobial property resulting in the suppression of cell growth of the test organism ATCC 8739 E. coli. It has a MIC value of 1.5% (w/v, 35°C, 20 hr) and could be useful as a new source of prebiotics or preservatives. The present results further confirm the science and useful application of combinatorial enzyme approach.

Mannan oligosaccharides alleviate oxidative injury in the head kidney and spleen in grass carp(Ctenopharyngodon idella)via the Nrf2 signaling pathway after Aeromonas hydrophila infection

Background Mannan oligosaccharides(MOS)are recommended as aquaculture additives owing to their excellent antioxidant properties.In the present study,we examined the effects of dietary MOS on the head kidney and spleen of grass carp(Ctenopharyngodon idella)with Aeromonas hydrophila infection.Methods A total of 540 grass carp were used for the study.They were administered six gradient dosages of the MOS diet(0,200,400,600,800,and 1,000 mg/kg)for 60 d.Subsequently,we performed a 14-day Aeromonas hydrophila challenge experiment.The antioxidant capacity of the head kidney and spleen were examined using spectrophotometry,DNA fragmentation,qRT-PCR,and Western blotting.Results After infection with Aeromonas hydrophila,400-600 mg/kg MOS supplementation decreased the levels of reactive oxygen species,protein carbonyl,and malonaldehyde and increased the levels of anti-superoxide anion,antihydroxyl radical,and glutathione in the head kidney and spleen of grass carp.The activities of copper-zinc superoxide dismutase,manganese superoxide dismutase,catalase,glutathione S-transferase,glutathione reductase,and glutathione peroxidase were also enhanced by supplementation with 400-600 mg/kg MOS.Furthermore,the expression of most antioxidant enzymes and their corresponding genes increased significantly with supplementation of 200-800 mg/kg MOS.mRNA and protein levels of nuclear factor erythroid 2-related factor 2 also increased following supplementation with 400-600 mg/kg MOS.In addition,supplementation with 400-600 mg/kg MOS reduced excessive apoptosis by inhibiting the death receptor pathway and mitochondrial pathway processes.Conclusions Based on the quadratic regression analysis of the above biomarkers(reactive oxygen species,malondialdehyde,and protein carbonyl)of oxidative damage in the head kidney and spleen of on-growing grass carp,the recommended MOS supplementation is 575.21,557.58,531.86,597.35,570.16,and 553.80 mg/kg,respectively.Collectively,MOS supplementation could alleviate oxidative injury in the head kidney and spleen of grass carp infected with Aeromonas hydrophila.

Multiplex genome editing targeting soybean with ultra-low anti-nutritive oligosaccharides

Soybean is the primary source of plant protein for humans.Owing to the indigestibility of the raffinose family of oligosaccharides(RFO),raffinose and stachyose are considered anti-nutritive factors in soybean seeds.Low-RFO soybean cultivars are generated by mutagenesis of RFO biosynthesis genes,but the carbohydrate profiles invite further modification to lower RFOs.This study employed a pooled multiplex genome editing approach to target four seed-specifically expressed genes mediating RFO biosynthesis,encoding three raffinose synthases(RS2,RS3,and RS4)and one stachyose synthase.In T1progeny,rs2/rs3 and rs4/sts homozygous double mutants and a rs2/rs3/rs4/sts quadruple mutant(rfo-4m)were characterized.The rs2/rs3 mutant showed reduced raffinose and stachyose contents,but the rs4/sts mutant showed only reduced stachyose in seeds.The RFO contents in the rfo-4m mutant were almost eliminated.Metabolomic analysis showed that the mutation of four RFO biosynthesis genes led to a shift of metabolic profile in the seeds,including the accumulation of several oligosaccharides-related metabolites.These mutants could contribute to precision breeding of soybean cultivars for soy food production.

Synthesis of chitosan oligosaccharide selenium and its antitumor activity

Background:Polysaccharides have various biological activities;the complexation of polysaccharides with trace element ions can produce synergistic effects,improving the original biological activities of sugars and trace elements.Methods:The preparation process of chitosan oligosaccharide selenium(COSSe)was optimized by the response surface method,followed by a detailed analysis of the resultant compound’s characteristics.The anti-cancer activity of COSSe was studied using the human ovarian cancer cell line SKOV3 as a cell model.Results:The prepared COSSe response surface was well predicted,indicating successful chitosan oligosaccharide binding with selenium.Response surface method analyses identified the optimal synthesis conditions for COSSe:the reaction time of 5.08 h,the reaction temperature of 71.8°C,and mass ratio(Na2SeO3:chitosan oligosaccharide)of 1.02.Under the optimal conditions,the final product,the selenium content,reached 1.302%.The results of cell experiments showed that COSSe significantly inhibited SKOV3 proliferation in a concentration-dependent manner.RNA-seq results showed that chitosan oligosaccharide and COSSe significantly modulated the expression of genes’DNA metabolic processes and cell cycle in SKOV3 cells.Gene enrichment analysis showed the inhibition of the cell cycle,and the results of flow cytometry showed that SKOV3 cells increased in the S phase and decreased in the G2/M phase,with a noted suppression in the protein expression of cyclin-dependent kinase 2(CDK2)and cyclin A1(CCNA1).Conclusion:COSSe has a stronger effect than chitosan oligosaccharide,leading to the arrest of the cell cycle in the S phase.Thus,COSSe may be an effective candidate for the treatment of ovarian cancer.

Alginate oligosaccharide-mediated butyrate-HIF-1a axis improves skin aging in mice

The“gut-skin”axis has been proved and is considered as a novel therapy for the prevention of skin aging.The antioxidant efficacy of oligomannonic acid(MAOS)makes it an intriguing target for use to improve skin aging.The present study further explored whereby MAOS-mediated gut-skin axis balance prevented skin aging in mice.The data indicated the skin aging phenotypes,oxidative stress,skin mitochondrial dysfunction,and intestinal dysbiosis(especially the butyrate and HIF-1a levels decreased)in aging mice.Similarly,fecal microbiota transplantation(FMT)from aging mice rebuild the aging-like phenotypes.Further,we demonstrated MAOS-mediated colonic butyrate-HIF-1a axis homeostasis promoted the entry of butyrate into the skin,upregulated mitophagy level and ultimately improving skin aging via HDAC3/PHD/HIF-1a/mitophagy loop in skin of mice.Overall,our study offered a better insights of the effectiveness of alginate oligosaccharides(AOS),promised to become a personalized targeted therapeutic agents,on gut-skin axis disorder inducing skin aging.

Structural elucidation of mulberry leaf oligosaccharide and its selective promotion of gut microbiota to alleviate type 2 diabetes mellitus

Two oligosaccharide fractions(MLO 2-1 and 2-2)were purified from enzymatic hydrolysate of mulberry leaf polysaccharide.The results of simulated digestion showed that MLO 2-2 was a digestible oligosaccharide,which could be degraded by human digestive juice;while MLO 2-1 possessed the non-digestible property in the upper gastrointestinal tract and performed the function by regulating the gut microbiota.Hence,MLO 2-1 was selected for the further analysis.The structure of MLO 2-1 was elucidated as follow:α-T-Glcp-(1→3)-β-Glcp-(1→5)-α-Araf-(1→5)-α-Araf-1→5)-α-Araf-(1→3)-α-(2-OAc)-Glcp-1.The in vitro fecal fermentation results showed that MLO 2-1 could modulate the composition of gut microbiota.Meanwhile,MLO 2-1 was effectively metabolized by fecal bacteria to produce lactate and short chain fatty acids,especially acetate and butyrate.The specific metabolic pathways of MLO 2-1 by gut microbiota were further illuminated.Gut microbiota analysis revealed that MLO 2-1 selectively promoted the growth of Ligilactobacillus murinus,a commensal bacterium presented a reduced level in T2DM mice.Animal experiments indicated that MLO 2-1 and L.murinus exhibited hypoglycemic activities.These results demonstrated that MLO 2-1 might alleviate T2DM by selectively accelerating the proliferation of L.murinus.

Formation of Oligosaccharide from Monosaccharide by Pentacoordinate Oxyphosphorane

Oxyphosphorane reacted with glucose to give disaccharide which was confirmed by FAB-MS and C-13-NMR. The mechanism for formation of oligosaccharides through the participation of phosphorus was proposed.

Effect of Specific Structure of Lotus Seed Oligosaccharides on the Production of Short-chain Fatty Acids by Bifidobacterium adolescentis

In order to study the structure of lotus （Nelumbo nucifera Gaertn） seed oligosaccharides and their effect on the proliferation ofBifidobacterium adolescentis, we extracted the oligosaccharides from seeds collected from Jianning County, China. We preliminarily characterized the groups, molecular weights, molecular formulae, component monosaccharides and glycosidic bonds using mass spectrometry （MS） and nuclear magnetic resonance （NMR） after isolation and purification. The lotus seed oligosaccharides contained glycosidic bonds Manp-（1→）, Galp-（1→）, α（1→6）-Glup and α（1→6）-Manp; and mannose was the chief component monosaccharide. NMR analyses showed that ~t-glycosidic bonds and pyranoid rings were predominant in the oligosaccharides. The MS analyses showed that lotus seed oligosaccharides consisted of three oligosaccharides of different polymerization degree, with relative molecular weights of 342, 504 and 666 Da, and corresponding molecular formulae C12H22O11, C18H32O16 and C24H42O21. Research on the effect of lotus seed oligosaccharides on the proliferation orB. adolescentis showed that they effectively promoted the production of acetic, propionic and butyric acids by B. adolescentis through fermentation, and their effect was stronger than that of fructo-, xylo- and isomalto-oligosaccharides. Lotus seed oligosaccharides have potential as a new functional probiotic and lotus seeds should be further explored and utilized as a source of oligosaccharides.

Effects of Different Oligosaccharides on Performance and Availability of Nutrients in Broilers

One hundred and forty-four Avin broilers (1 d of age) were randomly divided into six groups, with three replicates of eight birds each to study on the effects of different oligosaccharides on performance and availability of nutrients in broilers. The control group(Group I)was fed with corn-soybean meal as basal diet, and the trial groups (Group II, III, IV,V and VI) were fed with basal diet plus 0.1% Manoligosaccharides(MOS), 0.3% Soybean-Oligosaccharides(SBOS), 0.3% Fructo-oligosaccharides(FOS), 0.3% α-Glucooligosaccharides(α-GOS) and 50 mg·L-1 Chlortetracycline(CTC), respectively. The results showed that the supplementation of oligosaccharides slightly improved daily gain and feed intake. SBOS supplementation improved, but MOS and α-GOS significantly decreased availability of energy. Oligosaccharides supplementation improved availability of energy, phosphorus, calcium, magnesium and iron, and significantly increased cholesterol content of fecal, and did not affect on availability of protein and cholesterol contents in serum and muscle. Availability of phosphorus of broilers fed with FOS was much higher than that with α-GOS. SBOS supplementation remarkably increased availability of iron.

Polyguluronate Sulfate and Its Oligosaccharides but not Heparin Promotes FGF19/FGFR1c Signaling

Fibroblast growth factor 19(FGF19) functions as a hormone by affecting glucose metabolism. FGF19 improves glucose tolerance when overexpressed in mice with impaired glucose tolerance or diabetes. A functional cellular FGF19 receptor consists of FGF receptor(FGFR) and glycosaminoglycan complexed with either α Klotho or β Klotho. Interestingly, in mice with diet-induced diabetes, a single injection of FGF1 is enough to restore blood sugar levels to a healthy range. FGF1 binds heparin with high affinity whereas FGF19 does not, indicating that polysaccharides other than heparin might enhance FGF19/FGFR signaling. Using a FGFs/FGFR1 c signaling-dependent Ba F3 cell proliferation assay, we discovered that polyguluronate sulfate(PGS) and its oligosaccharides, PGS12 and PGS25, but not polyguluronate(PG), a natural marine polysaccharide, enhanced FGF19/FGFR1 c signaling better than that of heparin based on ~3H-thymidine incorporation. Interestingly, PGS6, PGS8, PGS10, PGS12, PGS25, and PGS, but not PG, had comparable FGF1/FGFR1 c signal-stimulating activity compared to that of heparin. These results indicated that PGS and its oligosaccharides were excellent FGF1/FGFR1 c and FGF19/FGFR1 c signaling enhancers at cellular level. Since the inexpensive PGS and PGS oligosaccharides can be absorbed through oral route, these seaweed-derived compounds merit further investigation as novel agents for the treatment of type 2 diabetes through enhancing FGF1/FGFR1 c and FGF19/FGFR1 c signaling in future.

Alginate oligosaccharides preparation, biological activities and their application in livestock and poultry

Alginate oligosaccharides(AOS), belonging to the class of functional marine oligosaccharides, are low-molecular polymers linked by β-1,4-mannuronic acid(M) and α-1,4-guluronic acid(G), which could be classically obtained by enzymatic hydrolysis of alginate. With low viscosity and good water solubility, as well as anti-oxidant, immune regulation, anti-bacterial and antiinflammatory activities, AOS have been widely used in medical science and functional food, green agriculture and other fields. As new bio-feed additives, AOS have broad potential applications in animal husbandry. In this review, the sources of alginate, chemical structure and preparation methods of AOS, and their biological activities and application in livestock and poultry are summarized. We expect this review could contribute to lay a foundation of application and further research for AOS in livestock and poultry.

Individual and Combined Effects of Nucleotides and Human Milk Oligosaccharides on Proliferation, Apoptosis and Necrosis in a Human Fetal Intestinal Cell Line

Nucleotides (NT) and human milk oligosaccharides (HMO) individually affect epithelial cell growth, but their combined effects had not been studied. Herein, the impact of NT and HMO on cell proliferation, apoptosis, necrosis and cell cycle in the fetal epithelial cell line (FHs-74 Int) was determined. Cells were incubated with media containing 2.5% FBS and no epidermal growth factor (Control);fucosyllactose (FL) mix [85% 2’FL/15% 3’FL], sialyllactose (SL) mix [40% 6’SL/10% 3’SL/50% sialic acid (SA)] or LNnT at 125, 250, 500 or 1000 μg/mL with and without 250 μg/mL NT (43% CMP, 18.5% UMP, 16.4% AMP, and 22.0% GMP) for 24 or 72 h. NT alone significantly increased proliferation, but did not affect cell cycle or apoptosis/necrosis. All HMO treatments at 1000 μg/mL significantly decreased proliferation and some were also inhibitory at 250 or 500 μg/mL. When NT and HMO were simultaneously added, NT ameliorated the anti-proliferative effect of HMO. FL significantly increased cells in S phase and SL and LNnT treatments significantly increased cells in G2/M and S phases, which concomitantly decreased cells in G0/G1. HMO with NT significantly decreased the percent of cells in the G2/M phase compared to HMO alone. Higher HMO doses significantly increased the percentage of apoptotic and necrotic cells compared to control. In conclusion, HMO reduced cell proliferation and this effect is partially ameliorated by NT. It appears that HMO initially induced apoptosis/necrosis, which was later evidenced by G2/M cell cycle arrest and decreased proliferation.

Human Milk Oligosaccharides Enhance Innate Immunity to Respiratory Syncytial Virus and Influenza <i>in Vitro</i>

Human milk oligosaccharides (HMO) contribute to innate immunity by enhancing growth of beneficial bacteria, epithelial cell maturation and mucosal barrier integrity. They have immunomodulatory effects and can block pathogen binding to host cell surface glycans or receptors. We investigated the effects of 2’-fucosyllactose (2’FL), 6’-sialyllactose (6’SL), 3’-sialyllactose (3’SL) and lacto-N-neoTetraose (LNnT) on human respiratory epithelial cell lines or peripheral blood mononuclear cells (PBMCs) following respiratory viral infectionin vitro. Expression of cytokines and viral load were monitored in infected cells. These biomarkers of innate immunity were selected since viral load and cytokine levels (IP-10, MIP-1α, IL-6, IL-8, TNF-α) have been correlated with disease severity in respiratory syncytial virus (RSV) and influenza (IAV) virus infectionin vivo. 2’FL significantly decreased RSV viral load and cytokines associated with disease severity (IL-6, IL-8, MIP-1α) and inflammation (TNF-α, MCP-1) in airway epithelial cells. LNnT and 6’SL significantly decreased IAV viral load in airway epithelial cells. 6’SL dose-dependently down-regulated IP-10 and TNF-α in RSV infected PBMCs. HMO at or below levels found in breast milk enhance innate immunity to respiratory viruses in vitro and may interact directly with cells to modulate biomarkers of innate immunity.

Laminarin and Laminarin Oligosaccharides Originating from Brown Algae:Preparation,Biological Activities,and Potential Applications

Brown algae is one of the three major types of marine algae and includes approximately 2000 species.It is widely dis-tributed in various seas around the world.Brown algae contain a plethora of active substances,such as polysaccharides,polyphe-nols,omega-3 fatty acids,and carotenoids.Laminarin,a type of storage carbohydrate found abundantly in brown algae,is mainly formed by glucose monomers linked byβ-1,3-glucosidic bonds and partialβ-1,6-glucosidic bonds.Laminarin and laminarin oligo-saccharides,which contain 2-10 saccharide units,have extensive biological activities,such as antitumor,antioxidant,anti-inflam-matory,and prebiotic properties.Moreover,both laminarin and laminarin oligosaccharides can be considered as ideal substrates for bioethanol production because they are composed of abundant glucose residues.Therefore,brown algae-derived laminarin and lami-narin oligosaccharides have various potential applications in the food,medicine,cosmetics,and bioenergy fields.This paper reviews the preparation methods of laminarin and laminarin oligosaccharides,as well as their biological activities and potential applications.

Analysis of the monosaccharide composition of fucoidan by precolumn derivation HPLC

We developed an HPLC method for analysis of the monosaccharide composition of fucoidans.The fucoidan was hydrolyzed into monosaccharides with 2 mol/L trifluoroacetic acid.Using ribose as the internal standard,the monosaccharide derivatives,obtained with 1-Phenyl-3-methyl-5-pyrazolone(PMP),were separated by reverse-phase HPLC using a gradient elution process,and monitored by ultraviolet detection at 245 nm.In the concentration range of 0.1-2.0 mmol/L,the peak area of each monosaccharide had a good linear relationship with its concentration(r2>0.998).The average recoveries of mannose,rhamnose,glucuronic acid,glucose,galactose,xylose,and fucose were 86.2%,95.1%,62.5%,102.0%,94.8%,66.6%,and 105.1%,respectively.This method was accurate and had good reproducibility and could be used to determine the monosaccharide contents of fucoidans.