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.

Efficient oxidation of monosaccharides to sugar acids under neutral condition in flow reactors with gold-supported activated carbon catalysts

A significant reaction in the synthesis of biomass-based chemicals is the catalyst-based and targeted oxidation of monosaccharides into valuable sugar acids.In this study,an activated carbon supported gold catalyst was used to oxidize glucose and xylose to gluconic acid and xylonic acid under neutral condition.Optimization of reaction conditions for the catalysts was performed using both a batch reactor and a flow-through reactor.In a batch reactor,the yields of gluconic and xylonic acid reached 93%and 92%,respectively,at 90℃ within 180 min.In a flow reactor,both reactions reached a similar yield at 80℃ with the weight hourly space velocity of 47.1 h^(-1).The reaction kinetics were explored in the flow reactor.The oxidation of glucose and xylose to gluconic and xylonic acid followed a first-order kinetics and the turnover frequency was 0.195 and 0.161 s^(-1),respectively.The activation energy was evaluated to be 60.58 and 59.30 kJ·mol^(-1),respectively.This study presents an environmentally friendly and feasible method for the selective oxidation of monosaccharides using an activated carbon supported gold catalyst,benefiting the high-value application of carbohydrates.

Methods for determination of absolute configuration of monosaccharides

Monosaccharides are one of the most important structural components of biomolecules, such as polysac- charides, nucleic acids, glycolipids and glycoproteins. In structural analysis of polysaccharides and gly- coconjugates, the absolute configurations （D or L） of the constituent monosaccharides are usually deter- mined by measurement of the optical rotation, CD spectra or characteristic chromatographic retention behavior. However, each method has its unique advantages and limitations which should be considered while using them. In this review, an overview of the different methods for the determination of absolute configuration of monosaccharides and their underlying principles are summarized to serve as a reference for researchers.

Pyrolysis Mechanism of Hemicellulose Monosaccharides in Different Catalytic Processes

The pyrolysis behaviors of four different hemicellulose monosaccharides, namely, two pentoses（xylose and arabinose） and two hexoses（mannose and galactose） catalyzed by HZSM-5 were investigated. The effects of two different processes by which the catalyst comes into contact with the substrate, namely, mixed with monosaccha- ride（in-bed） or layered above monosaccharide（in situ）, were compared. Evolution characteristics of typical pyrolytic products（H20, CO2, acids, furans and aromatics） were achieved by thermogravimetry-Fourier transform infrared spectroscopy. The in-bed catalytic process significantly lowered the pyrolytic temperature and increased the produc- tion of furans and acids at a low temperature by enhancing dehydration, retro-aldol fragmentation and Grob fragmen- tation. During the in situ catalytic process, volatiles generated from monosaccharides passed through a catalyst bed and underwent further dehydration, decarboxylation, and decarbonylation, significantly lowering the yields of acids and furans. The yield of aromatics was enhanced, and the corresponding volatilization temperature was lowered, es- pecially under the in-bed catalytic conditions. Pentoses entered into the zeolite pores more easily than hexoses did because of their smaller molecular size; thus, the in-bed catalytic process drastically affected pentose pyrolysis.

Enthalpy and entropy interaction parameters of sodium chloride with some monosaccharides in water

Dilution enthalpies of sodium chloride and some monosaccharides (glucose, galactose, xylose, arabinose, and fructose) in water and mixing enthalpies of aqueous sodium chloride and these monosaccharide solutions were measured by using an improved precision semimicro-titration calorimeter. Transfer enthalpies of sodium chloride from water to aqueous saccharide solutions were evaluated as well as enthalpy interaction parameters of sodium chloride with these monosaccharides in water. Combined with Gibbs energy interaction parameters, entropy interaction parameters were also obtained. The results show that interactions of the saccharides with sodium chloride depend on the stereochemistry of saccharide molecules. These interaction parameters can identify stereochemical structure of saccharide molecules. Keywords sodium chloride - monosaccharide - enthalpy interaction parameter - entropy interaction parameter - calorimetry

The effect of monosaccharides on self-assembly of benzenetricarboxamides

The interaction between monosaccharides exhibits an important role in the assembly of monosaccharide-containing molecules. In this work, three common monosaccharides, glucose, galactose and mannose, are employed to investigate the effect of monosaccharide on the self-assembly of benzenetricarboxamide(BTA) core-containing molecules. In the presence of monosaccharides, three benzenetricarboxamide derivatives aggregate into different ordered structures. When alanine linkers are introduced to these molecules between the core and the monosacchride, morphologies of three types of monosaccharide BTAs turned to disordered, meanwhile their structures become similar with the increase of the length of alanine linkers, indicating the disappearance of the monosaccharide effects.

Diet and functional dyspepsia: Clinical correlates and therapeutic perspectives

Hypervigilance and symptoms anticipation,visceral hypersensitivity and gastroduodenal sensorimotor abnormalities account for the varied clinical presentation of functional dyspepsia(FD)patients.Many patients recognize meals as the main triggering factor;thus,dietary manipulations often represent the first-line management strategy in this cohort of patients.Nonetheless,scarce quality evidence has been produced regarding the relationship between specific foods and/or macronutrients and the onset of FD symptoms,resulting in nonstandardized nutritional approaches.Most dietary advises are indeed empirical and often lead to exclusion diets,reinforcing in patients the perception of“being intolerant”to food and self-perpetuating some of the very mechanisms underlying dyspepsia physiopathology(i.e.,hypervigilance and symptom anticipation).Clinicians are often uncertain regarding the contribution of specific foods to dyspepsia physiopathology and dedicated professionals(i.e.,dietitians)are only available in tertiary referral settings.This in turn,can result in nutritionally unbalanced diets and could even encourage restrictive eating behaviors in severe dyspepsia.In this review,we aim at evaluating the relationship between dietary habits,macronutrients and specific foods in determining FD symptoms.We will provide an overview of the evidence-based nutritional approach that should be pursued in these patients,providing clinicians with a valuable tool in standardizing nutritional advises and discouraging patients from engaging into indiscriminate food exclusions.

The Effect of Thoracic Operation on Glucose Transporter-4 mRNA Expression by Preoperative Infusion of Glucose

Objective: To investigate the changes in glucose transporter-4(Glut-4) mRNA expression in skeletal muscle before and after the thoracic operation and to observe the changes in Glut-4 mRNA expression by preoperative infusion of glucose. Methods: Twelve cases of elective thoracic operation were randomly divided into two groups, namely ordinary group Ⅰ and glucose infusion group Ⅱ. One gram of intercostal muscle was taken while thorax being opened and closed from patients under general anesthesia. Total RNA of the muscle cells was extracted by TRIzol one-step assay. Reverse transcription-competitive polymerase chain reaction (RT-PCR) was used to determine the Glut-4 mRNA amplification products with β-actin mRNA as an internal control. The Glut-4 mRNA expression was expressed by targeted gene /β-actin ×100%. The plasma glucose and insulin levels were determined at the same time.Results: Glut-4 mRNA expression was significantly reduced(P<0.05) and plasma glucose level increased (P<0.05), while thorax was being closed as compared with those while being opened. However, Glut-4 mRNA expression in glucose infusion group Ⅱ was significantly higher than ordinary group Ⅰ (P<0.01) and plasma glucose level in group Ⅱ was lower than group Ⅰ(P<0.05) when thorax was being closed. Conclusion: The results indicate that the synthesis of Glut-4 is suppressed by the surgical stress of thoracic operation under general anesthesia. We found that preoperative infusion glucose can increase Glut-4 mRNA expression at the same surgical stress and relieve postoperative insulin resistance.

SYNTHESIS,HELICITY,AND BIOLOGICAL PROPERTIES OF MONOSACCHARIDE-CONTAININGPOLY(PHENYLACETYLENE)S

Poly（phenylacetylene）s beating monosaccharide pendant groups are synthesized in high yields by [Rh（nbd）Cl]2 catalyst. The polymers have high molecular weights and give satisfactory spectroscopic data corresponding to their molecular structures. They are thermally quite stable （≥ 300℃） and show strong circular dichroism signals in the visible spectral region owing to the helicity of the polyene backbone. The monosaccharide-containing polyacetylenes are cytophilic and can stimulate the growth of living cells.

Seasonal variations and distributions of dissolved free and total carbohydrates at the ?zmir Bay, Aegean Sea

Seasonal variations and distributions of dissolved carbohydrate concentrations at the ？zmir Bay were investigated with salinity, chlorophyll a（Chl a）, and dissolved organic carbon（DOC） levels to understand their relationships.Samples were collected from surface, subsurface and bottom depths at seven stations. DOC concentrations ranged from 32.2 to 244.2 μmol/L, and in general, DOC levels increased from winter to summer, then slightly decreased in autumn. Monosaccharide（MCHO）, polysaccharide（PCHO） and total dissolved carbohydrate（TDCHO） levels were found between 0.7–8.3, 0.7–19.5, and 2.6–24.6 μmol/L. DOC, MCHO, PCHO and TDCHO levels were found higher in middle-inner bays, under the influence of anthropogenic inputs, compared to outer bay. Seasonal changes of MCHO/DOC, PCHO/DOC and TDCHO/DOC ratios were statistically significant（p〈0.05）and the ratios showed decrease trends from winter to summer-autumn seasons. Distributions of TDCHO/DOC ratios at wide ranges（2.5%–42.3%） indicated the presence of newly forming and degrading fractions of DOM.According to results of factor analysis, Chl a, MCHO and TDCHO were explained in the same factor groups. In conclusion, the results showed that dissolved carbohydrate levels in the ？zmir Bay might be influenced by biological processes and terrestrial/anthropogenic inputs.

Characteristics of dissolved sugars in the Southern Yap Trench from sea surface to hadal zone

2,4,6-Tripyridine-s-triazine(TPTZ)spectrophotometric method was applied to determine the concentrations of dissolved monosaccharides(MCHO),polysaccharides(PCHO),and total carbohydrate(TCHO)in seawater samples collected from sea surface to hadal zone and sediment-seawater interface of the Southern Yap Trench in the Western Pacific Ocean.Results show that the concentrations of MCHO,PCHO,and TCHO ranged from 6.3 to 22.3μmol C/L,1.1 to 25.4μmol C/L,and 12.1 to 44.9μmol C/L,respectively,from the euphotic layer to the hadal zone of the trench.At different sampling stations,the concentrations of MCHO,PCHO,and TCHO in the seawater showed complex vertical variation characteristics,but the overall variation trends were decreasing with water depth.In the Southern Yap Trench,the maximum concentration of MCHO in the seawater appeared in the euphotic layer,and the minimum in the hadal zone.The maximum concentration of PCHO appeared in the euphotic layer,and the minimum in the bathypelagic layer.The water layer where the maxima and minima of the average concentration of TCHO appeared was consistent with that of PCHO.PCHO was the major component of TCHO in the seawater of the Southern Yap Trench.In the seawater from the sediment-seawater interface,the concentrations of MCHO,PCHO,and TCHO ranged from 8.4 to 10.6μmol C/L,3.8 to 5.8μmol C/L,and 12.2 to 15.2μmol C/L,respectively,and MCHO was the major component of TCHO.The key factors affecting the concentration and existing forms of dissolved sugars in the seawater of the Southern Yap Trench included photosynthesis,respiration,polysaccharide hydrolysis,adsorption and desorption of particulate matter,trench“funnel effect”,deep ocean currents,sediment resuspension,and etc.This study provided fundamental data about labile organic matter in abyss and hadal zone of marine environment,which is significant for further understanding of deep-sea organic carbon cycle.

Rapid Method for the Determination of Total Monosaccharide in <i>Enterobacter cloacae</i>Strains Using Fourier Transform Infrared Spectroscopy

Fourier Transform Infrared Spectroscopy (FTIR) was used to quantify total monosaccharide content in the bacterium Enterobacter cloacae and several of its biofilm mutants. Bacterial biofilm samples were grown on trypticase soy agar, and 30 μL aliquots of aqueous sample bacterial plus biofilm were deposited into the center of barium fluoride crystals and dried at 50°C for 1-hour before being scanned by FTIR. The total amounts of monosaccharides were estimated using the absorbance of the mono-saccharide peak, 1192 - 958 cm–1, and normalized using the amide II peak, 1585 - 1483 cm–1. This method provided a linear correlation between the absorbance of the monosaccharide peak and concentration of monosaccharide in standard monosaccharides, fructose, glucose, mannose, and rhamnose, over a concentration range of 0.5 - 2.0 mg/mL.

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 monosaecharide 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 （r^2〉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.

COMPARISON OF POLYSACCHARIDES ISOLATED FROM THE MYCELIA OF A CULTIVATED STRAIN OF PORIA COCOS GROWN IN DIFFERENT LIQUID CULTURE MEDIA

Mycelium of a cultivated strain of Poria cocos was grown by submerged fermentation in a liquid mediumcontaining corn steep liquor with orbital shaking. Six polysaccharides coded as ac-PCM1, ac-PCM2, ac-PCM3-Ⅰ andⅡ, ac-PCM4-Ⅰand Ⅱ were isolated from the myelium by extracting with 0.9% NaCl aqueous solution, hot water, 0.5 mol/L NaOHaqueous solution and 88% formic acid. Exo-polysaccharide was obtained from the culture medium and coded as ac-PCM0.The monosaccharide composition and molecular weights of these polysaccharides were characterized by using infraredspectroscopy, gas chromaography, elemental analysis, ^(13)C-NMR, viscometry and light scattering. The results indicated thatac-PCM0, ac-PCM1 and ac-PCM2 are heteropolysaccharides containing glucose, galactose, mannose and fucose, and ac-PCM3-Ⅰ and ac-PCM3-Ⅱ mainly consist of D-glucose. The content of the glucose in the polysaccharides increased with theisolation progress. Remarkably, α-glucan and β-glucan coexisted in the extract by NaOH aqueous solution (ac-PCM3), andcould be separated by chemical methods. The protein in the ac-PCM polysaccharides cultured from the medium containingcorn steep liquor was higher than that in the ab-PCM from the medium with bran extract. Therefore, the polysaccharidesfrom Poria cocos mycelia cultured in different media have different chemical composition, molecular weights and conformations.

Properties of Polysaccharides in Several Seaweeds from Atlantic Canada and Their Potential Anti-Influenza Viral Activities

To explore the polysaccharides from selected seaweeds of Atlantic Canada and to evaluate their potential anti-influenza virus activities, polysaccharides were isolated from several Atlantic Canadian seaweeds, including three red algae (Polysiphonia lanosa, Furcellaria lumbricalis, and Palmaria palmata), two brown algae (Ascophyllum nodosum and Fucus vesiculosus), and one green alga (Ulva lactuca) by sequential extraction with cold water, hot water, and alkali solutions. These polysaccharides were ana-lyzed for monosaccharide composition and other general chemical properties, and they were evaluated for anti-influenza virus activities. Total sugar contents in these polysaccharides ranged from 15.4% (in U. lactuca) to 91.4% (in F. lumbricalis); sulfation level was as high as 17.6% in a polysaccharide from U. lactuca, whereas it could not be detected in an alikali-extract from P. palmaria. For polysaccharides from red seaweeds, the main sugar units were sulfated galactans (agar or carrageenan) for P. lanosa, F. lumbricalis, and xylans for P. palmata. In brown seaweeds, the polysaccharides largely contained sulfated fucans, whereas the polysaccharides in green seaweed were mainly composed of heteroglycuronans. Screening for antiviral activity against influenza A/PR/8/34 (H1N1) virus revealed that brown algal polysaccharides were particularly effective. Seaweeds from Atlantic Canada are a good source of marine polysaccharides with potential antiviral properties.

Vertical variations of dissolved carbohydrates in the North Yap Trench

The concentrations of dissolved monosaccharides(MCHO),polysaccharides(PCHO),and total carbohydrates(TCHO)in the seawater samples collected from the north of the Yap Trench in the western Pacific Ocean were measured by 2,4,6-tripyridine-s-triazine(TPTZ)spectrophotometry method.The results show that the concentrations of MCHO,PCHO,and TCHO ranged from 4.6 to 22.1μmol C/L,3.5 to 27.3μmol C/L,and 13.8 to 36.3μmol C/L,respectively.In different sampling stations,the concentrations of MCHO,PCHO,and TCHO with water depth showed complex variation patterns.In the study area,the maximum concentrations of MCHO,PCHO,and TCHO occurred in the euphotic layer and the minimum concentrations occurred in mesopelagic seawater layer.Generally,the concentrations of MCHO,PCHO,and TCHO decreased with water depth from the euphotic layer to the hadal zone.The average value of PCHO/TCHO was higher than the average value of MCHO/TCHO,indicating that PCHO was the main component of TCHO in north of the Yap Trench.

Identification of Two Cold Water-Soluble Polysaccharides from the Stems of Ephedra sinica Stapf

Two polysaccharides (ESP-A1 and ESP-A2) were isolated from the cold water extract of Ephedra sinica Stapf and purified through ethanol precipitation, deproteinization and by ion exchange and gel-filtration chromatography. Their molecular weight was determined using high performance size exclusion chromatog-raphy and evaporative light scattering detector (HPSEC-ELSD) and their monosaccharide composition was analyzed by high performance capillary electrophoresis (HPCE) based on pre-column derivatization with 1-phenyl-3-methyl-5-pyrazolone (PMP). It was shown that ESP-A1 consisted of xylose, arabinose, glucose, mannose and galactose and ESP-A2 consisted of xylose, arabinose, rhamnose and galactose, in a molar ratio (%) of 3.2: 61.1: 11.1: 12.9: 11.6 and 20.6: 67.7: 5.0: 6.7, respectively. The molecular weights (Mw) of ESP-A1 and ESP-A2 were 5.83 × 104 Da and more than 200 × 104 Da, respectively. To the best of our knowledge, two neutral polysaccharides are now being reported for the first time in this study.

Production and characterization of exopolysaccharides in mycelial culture of Cordyceps sinensis fungus Cs-HK1 with different carbon sources

The effects of different carbon sources(sugars) on the production and molecular properties of exopolysaccharides(EPS) were evaluated in the mycelial liquid culture of a medicinal fungus Cordyceps sinensis Cs-HK1. Galactose or mannose was used(at 5 g·L^(-1)) as a secondary carbon source with glucose(35 g·L^(-1)) at the mass ratio of 1:7. Mannose was consumed notably since the first day of culture, but galactose was not even after glucose was exhausted.The volumetric yield of EPS in culture was increased slightly with the addition of galactose and decreased with mannose. The monosaccharide composition of EPS was also different, e.g., on day 8, the glucose contents of EPS were 76%with the addition of mannose, 59% with galactose, compared with 62% with glucose only. The molecular weight distribution of EPS was also affected by the secondary carbon source, being generally lower compared with that with glucose only. The results suggested that the addition of galactose improved the total yield of EPS in culture while mannose can improve the yield of glucan constituent of EPS.

A new monosaccharide from Swertia punicea Hemsl

A new compound named 1-hydrate, 3-deoxy-α-D-tagatofuranose was isolated from Swertia punicea Hemsl. The structure of compound was determined by 1D and 2D NMR, HRESIMS techniques.

Determination of the Composition and Content of Lycium barbarum Polysaccharides by Chromatography

Lycium barbarum polysaccharides （LBP） were obtained after Lycium barbarum, the study object, went through chloroform-methanol degreasing, water extraction and alcohol precipitation, acetone and ether wash and dry, hydrogen peroxide bleaching, deproteinization by savage method. Determined LBP molecular weight by HPLC was 73950-138090Da. And the monosaccharides in LBP determined by IC mainly included glucose, arabinose, rhamnose, galactose, xylose and mannose, in which glucose, arabinose and galactose had larger contents, while the contents of other monosaccharides were low.