Distribution Of Oligosaccharides Research Articles

Effects of High Hydrostatic Pressure on the Distribution of Oligosaccharides, Pinitol, Soysapapogenol A, and Fatty Acids in Soybean.

The effects of high hydrostatic pressure (HHP) treatment (100-600 MPa for 10-60 min) and thermal treatment (boiling for 10-60 min) on oligosaccharides, pinitol, and soyasapogenol A as taste ingredients in soybean (Glycine max (L.) Merr.) (cv. Yukihomare) were evaluated. Additionally, soybean-derived fatty acids such as α-linolenic acid, linoleic acid, oleic acid, palmitic acid, and stearic acid in pressurized soybeans were quantitatively analyzed. Sucrose, stachyose, and raffinose concentrations were decreased in all tested pressure and time combinations; however, pinitol concentrations were increased by specific pressure and time combinations at 100-400 MPa for 10-60 min. While the soyasapogenol A content in boiled soybeans decreased with increasing boiling time, that of pressurized soybeans was altered by specific pressure and time combinations. At the lower pressure and shorter time combinations, the essential fatty acids such as α-linolenic acid and linoleic acid showed higher contents. Stearic acid and oleic acid contents of pressurized soybeans increased at mild pressure levels (300-500 MPa). In contrast, the combination of higher pressure and longer time results in lower essential fatty acid contents. Non-thermal-pressurized soybeans have the potential to be a high-value food source with better taste due to the enrichment of low molecular weight components such as pinitol, free amino acids, and the reduction of isoflavones and Group A soyasapogenol.

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.

Identification of raffinose family oligosaccharides in processed Rehmannia glutinosa Libosch using matrix-assisted laser desorption/ionization mass spectrometry image combined with machine learning.

Currently, research on oligosaccharides primarily focuses on the physiological activity and function, with a few studies elaborating on the spatial distribution characterization and variation in the processing of Rehmannia glutinosa Libosch. Thus, imaging the spatial distributions and dynamic changes in oligosaccharides during the steaming process is significant for characterizing the metabolic networks of R. glutinosa. It will be beneficial to characterize the impact of steaming on the active ingredients and distribution patterns in different parts of the plant. A highly sensitive matrix-assisted laser desorption/ionization mass spectrometry image (MALDI-MSI) method was used to visualize the spatial distribution of oligosaccharides in processed R. glutinosa. Furthermore, machine learning was used to distinguish the processed R. glutinosa samples obtained under different steaming conditions. Imaging results showed that the oligosaccharides in the fresh R. glutinosa were mainly distributed in the cortex and xylem. As steaming progressed, the tetra- and pentasaccharides were hydrolyzed and diffused gradually into the tissue section. MALDI-MS profiling combined with machine learning was used to identify the processed R. glutinosa samples accurately at different steaming intervals. Eight algorithms were used to build classification machine learning models, which were evaluated for accuracy, precision, recall, and F1 score. The linear discriminant analysis and random forest models performed the best, with prediction accuracies of 0.98 and 0.97, respectively, and thus can be considered for identifying the steaming durations of R. glutinosa. MALDI-MSI combined with machine learning can be used to visualize the distribution of oligosaccharides and identify the processed samples after steaming for different durations. This can enhance our understanding of the metabolic changes that occur during the steaming process of R. glutinosa; meanwhile, it is expected to provide a theoretical reference for the standardization and modernization of processing in the field of medicinal plants.

Effect of the immobilization of pectinase on the molecular weight distribution of pectin oligosaccharides obtained from citrus pectin

Current sustainability guidelines require industrial byproducts to be returned to the production cycle. One of the most important byproducts for agriculture and food production is pectin, which can be hydrolyzed to obtain pectin oligosaccharides (POS), with potential use as prebiotics. One of the challenges in POS production is the modulation of their molecular weight since those between 1 and 3 kDa exhibit higher prebiotic activity. In this work, a pectinase preparation was used for pectin hydrolysis, evaluating the effect of enzyme immobilization on the molecular weight distribution of the obtained POS. The pectinase preparation immobilized on functionalized silica with amino and glyoxyl groups and expressed 88.6 U per g of support. Enzyme immobilization improves thermal resistance at 50 °C and pH 4.0 compared to soluble pectinase. Immobilization also influences pectin hydrolysis and thus the POS generation, increasing yield by 10% when the immobilized pectinase was used. Interestingly, pectinase immobilization resulted in an average of 2.5 kDa for obtained POS.In contrast, soluble pectinase resulted in a continuous decrease of POS molecular weight over hydrolysis time. This difference could be attributed to the enzyme confinement on the porous silica, limiting the reduction in molecular weight of POS, probably because the immobilized enzyme exhibits higher diffusional restrictions than free enzymes. Our results help to understand and design an efficient and sustainable process to produce tailored prebiotic molecules from agro-industrial byproducts.

Multiple reaction monitoring for identification and quantification of oligosaccharides in legumes using a triple quadrupole mass spectrometer

Raffinose family oligosaccharides are non-digestible compounds considered as dietary prebiotics with health-related properties. Hence, it is important to develop highly specific methods for their determination. An analytical method is developed in this study for oligosaccharide identification and quantification using liquid chromatography-tandem mass spectrometry equipped with a triple quadrupole analyser operating in Multiple Reaction Monitoring mode. Raffinose, stachyose and verbascose are separated in a 10-minute run and the method is validated over a broad concentration range, showing good linearity, accuracy, precision and high sensitivity. A low-cost, short eco-friendly procedure for oligosaccharide extraction from legumes, with a high recovery rate extraction, good repeatability and reproducibility is also proposed. No plant-matrix effects were demonstrated. The method applied to the screening of 28 different legumes revealed species-related traits for oligosaccharide distribution, highlighting Pisum sativum (9.22 g/100 g) as the richest source of these prebiotics and its suitability as a functional food ingredient.

Mammal hyaluronidase activity on chondroitin sulfate and dermatan sulfate: Mass spectrometry analysis of oligosaccharide products.

Mammalian hyaluronidases are endo-N-acetyl-D-hexosaminidases involved in the catabolism of hyaluronic acid (HA) but their role in the catabolism of chondroitin sulfate (CS) is also examined. HA and CS are glycosaminoglycans implicated in several physiological and pathological processes, and understanding their metabolism is of significant importance. Data have been previously reported on the degradation of CS under the action of hyaluronidase, yet a detailed structural investigation of CS depolymerization products remains necessary to improve our knowledge of the CS depolymerizing activity of hyaluronidase. For that purpose, the fine structural characterization of CS oligosaccharides formed upon the enzymatic depolymerization of various CS subtypes by hyaluronidase has been carried out by high-resolution Orbitrap mass spectrometry (MS) and extreme UV (XUV) photodissociation tandem MS. The exact mass measurements show the formation of wide size range of even oligosaccharides upon digestion of CS-A and CS-C comprising hexa- and octa-saccharides among the main digestion products, as well as formation of small quantities of odd-numbered oligosaccharides, while no hyaluronidase activity was detected on CS-B. In addition, slight differences have been observed in the distribution of oligosaccharides in the digestion mixture of CS-A and CS-C, the contribution of longer oligosaccharides being significantly higher for CS-C. The sequence of CS oligosaccharide products determined XUV photodissociation experiments verifies the selective β(1→4) glycosidic bond cleavage catalyzed by mammal hyaluronidase. The ability of the mammal hyaluronidase to produce hexa- and higher oligosaccharides supports its role in the catabolism of CS anchored to membrane proteoglycans and in extra-cellular matrix.

Evolution of the molar mass distribution of oat β-glucan during acid catalyzed hydrolysis in aqueous solution

Reactivity of the glycosidic bonds in oat β-glucan in homogeneous acid catalyzed hydrolysis in aqueous solution was found to depend on their position in the polysaccharide chain. The bonds near the chain ends have lower hydrolytic stability in presence of HCl than the bonds in the middle. Reaction kinetics was monitored by measuring the molar mass distribution (DP ~ 30…3500) and formation of short oligosaccharides (DP < 6) under mild conditions (T = 50 °C…80 °C, cHCl = 0.05…0.25 M). Accuracy of the molar mass determination using analytical scale size-exclusion chromatography and multi-angle laser light scattering was improved by carrying out preparative scale size-exclusion separation as a pretreatment. It was found that monitoring the short-chain degradation products in addition to the molar mass distribution provides valuable information about the hydrolysis rate. The data were successfully correlated with a kinetic model that takes into account the non-random structure of oat β-glucan. The rate of cleavage of the terminal glycosidic bonds was found to be almost three times higher than at a distance of 20 or more glucose units from the chain end. The β-(1,3) bonds in oat β-glucan were found less stable against acid catalyzed hydrolysis than the β-(1,4) bonds.

Biopurification of Oligosaccharides by Immobilized Kluyveromyces Lactis

Oligosaccharides with diverse and complex structures such as milk oligosaccharides have physiological functions including modulating intestinal microbiota or stimulating immune cell responses. However, milk carbohydrates include about 40–50% of lactose which requires a cost-effective method to separate. We developed a new method to purify the oligosaccharides from carbohydrate mixtures such as human milk oligosaccharides (HMOs) and galactooligosaccharides (GOSs) by exploiting immobilized Kluyveromyces lactis as microbial catalysts. Evaluation of media components exhibited no significant differences in the lactose removal efficiency when nutrient-rich media, minimal salt media, and distilled water without any media components were used. With the immobilization on alginate beads, the lactose removal efficiency was increased 3.4 fold compared to that of suspension culture. When the immobilized cells were reused to design a continuous process, 4 h of pre-activation enhanced the lactose eliminating performance 2.5 fold. Finally, immobilized K. lactis was used as microbial catalysts for the biopurification of HMOs and GOSs, and lactose was effectively removed without altering the overall distribution of oligosaccharides.

Lectin binding patterns and immunohistochemical antigen detection in placenta and lungs of Brucella abortus-bovine infected fetuses.

Lectin binding relies on the affinity of these substances for specific terminal sugars. The method facilitates the identification of complex structures to which the terminal sugar attaches and may reveal physiological or pathological changes in cells, intracellular interactions or extracellular transport pathways. This study was carried out to investigate the effect of infection with Brucella abortus on the pattern of lectin binding in bovine fetal lungs (n=6) and bovine placentas (n=5). Fetal lungs and placenta from heifers experimentally inoculated with B. abortus, strain 2308 were examined by histological, lectin-histochemical, immunohistochemical and cultural techniques. B. abortus antigens were immunohistochemically detected in fetal lungs and placenta. An increase in the labeling with UEA-1, DBA, PNA, RCA-1 and SBA was found in the lungs and an increase in the labeling with UEA-1, ConA, PNA, DBA was found in the placentas. The present lectin histochemical study revealed a distinctive pattern of oligosaccharide distribution in the lungs and placenta of B. abortus-infected fetuses.

Glycosaminoglycan fragments as a measure of disease burden in the mucopolysaccharidosis type I mouse.

Glycosaminoglycan (GAG) catabolism involves endo-hydrolysis of polysaccharides followed by the sequential removal of the non-reducing end residue from the resulting oligosaccharides by exo-enzymes. In the inherited metabolic disorder, mucopolysaccharidosis type I (MPS I), a deficiency in the exo-enzyme, α-l-iduronidase, prevents removal of α-l-iduronic acid residues from the non-reducing end of the GAGs, heparan sulphate (HS) and dermatan sulphate (DS). The excretion of partially degraded HS and DS in urine of MPS I patients has long been recognized, but the question of whether they do indeed reflect GAG load in a particular tissue has not been addressed - an important issue in the context of biomarkers for assessment of disease burden in MPS I. Therefore, we measured specific low molecular weight HS and DS oligosaccharides with terminal α-l-iduronic acid residues, in the brain, liver, kidney, serum and urine, and correlated these findings with total GAG in the MPS I mouse model. Six oligosaccharides were identified in the urine, ranging from di- to pentasaccharides. Of these, five were observed in the kidney, four in the liver and brain, with the three most abundant in urine also seen in serum. These oligosaccharides accounted for just 0.1-2% of total GAG, with a disaccharide showing the best correlation with total GAG. The oligosaccharides and total GAG were most abundant in the liver, with the least observed in the brain. The concentration of oligosaccharides as a percentage of total GAG in urine was similar to that observed in the kidney, and both revealed a similar ratio of HS:DS, suggesting that the oligosaccharide storage pattern in urine is a reflection of that in the kidney. Serum, liver and brain had a similar ratio of HS:DS, which was lower to that seen in the urine and kidney. The distribution of oligosaccharides when ranked from most to least abundant, was also the same between serum, liver and brain suggesting that serum more closely reflects the oligosaccharides of the brain and liver and may therefore be a more informative measurement of disease burden than urine. The accumulation of HS and DS oligosaccharides was observed in the brain as early as one month of age, with the disaccharide showing a continuous increase with age. This demonstrates the progressive nature of the disease and as such this disaccharide could prove to be a useful biomarker to measure disease burden in MPS I.

In Vitro Evidence for Immune-Modulatory Properties of Non-Digestible Oligosaccharides: Direct Effect on Human Monocyte Derived Dendritic Cells.

Infant formulas containing non-digestible oligosaccharides (NDO) similar to the composition in breast milk or a combination of lactic acid bacteria (LAB) and NDO have been shown to harbor preventive effects towards immune-regulatory disorders. The aim of this study was to investigate the immune-modulatory potential of non-digestible short chain galacto- and long chain fructo-oligosaccharides (scGOS/lcFOS) mimicking the natural distribution of oligosaccharides in human breast milk in presence or absence of certain LAB strains in human monocyte derived dendritic cells (MoDC). Immature human MoDC prepared from peripheral blood of healthy non-atopic volunteers were screened in vitro after stimulation with specific scGOS/lcFOS in presence or absence of LAB. IL-10 and IL-12p70 release was analyzed after 24 hours in cell-free supernatants by enzyme-linked immunosorbent assay (ELISA). A luminex-based assay was conducted to assess further cytokine and chemokine release by MoDC. To investigate the resulting T cell response, stimulated MoDC were co-incubated with naïve T cells in allogeneic stimulation assays and intracellular Foxp3 expression, as well as immune-suppressive capacity was determined. Oligosaccharides did not induce relevant amounts of IL-12p70 production, but did promote IL-10 release by MoDC. Furthermore, scGOS/lcFOS mixtures exerted a significant enhancing effect on LAB induced IL-10 secretion by MoDC while no increase in IL-12p70 production was observed. Blocking toll like receptor (TLR)4 abrogated the increase in IL-10 in both the direct stimulation and the LAB stimulation of MoDC, suggesting that scGOS/lcFOS act via TLR4. Finally, scGOS/lcFOS-treated MoDC were shown to upregulate the number of functional suppressive Foxp3 positive T cells following allogeneic stimulation. Our results indicate anti-inflammatory and direct, microbiota independent, immune-modulatory properties of scGOS/lcFOS mixtures on human MoDC suggesting a possible induction of regulatory T cells (Tregs). The tested combinations of LAB and scGOS/lcFOS might represent a useful dietary ingredient for the maintenance of intestinal homeostasis via the induction of Tregs.

An update on oligosaccharides and their esters from traditional chinese medicines: chemical structures and biological activities.

A great number of naturally occurring oligosaccharides and oligosaccharide esters have been isolated from traditional Chinese medicinal plants, which are used widely in Asia and show prominent curative effects in the prevention and treatment of kinds of diseases. Numerous in vitro and in vivo experiments have revealed that oligosaccharides and their esters exhibited various activities, including antioxidant, antidepressant, cytotoxic, antineoplastic, anti-inflammatory, neuroprotective, cerebral protective, antidiabetic, plant growth-regulatory, and immunopotentiating activities. This review summarizes the investigations on the distribution, chemical structures, and bioactivities of natural oligosaccharides and their esters from traditional Chinese medicines between 2003 and 2013.

Subcellular distribution of raffinose oligosaccharides and other metabolites in summer and winter leaves of Ajuga reptans (Lamiaceae).

In Ajuga reptans, raffinose oligosaccharides accumulated during winter. Stachyose, verbascose, and higher RFO oligomers were exclusively found in the vacuole whereas one-fourth of raffinose was localized in the stroma. The evergreen labiate Ajuga reptans L. can grow at low temperature. The carbohydrate metabolism changes during the cold phase, e.g., raffinose family oligosaccharides (RFOs) accumulate. Additionally, A. reptans translocates RFOs in the phloem. In the present study, subcellular concentrations of metabolites were studied in summer and winter leaves of A. reptans to gain further insight into regulatory instances involved in the cold acclimation process and into the function of RFOs. Subcellular metabolite concentrations were determined by non-aqueous fractionation. Volumes of the subcellular compartments of summer and winter leaves were analyzed by morphometric measurements. The metabolite content varied strongly between summer and winter leaves. Soluble metabolites increased up to tenfold during winter whereas the starch content was decreased. In winter leaves, the subcellular distribution showed a shift of carbohydrates from cytoplasm to vacuole and chloroplast. Despite this, the metabolite concentration was higher in all compartments in winter leaves compared to summer leaves because of the much higher total metabolite content in winter leaves. The different oligosaccharides did show different compartmentations. Stachyose, verbascose, and higher RFO oligomers were almost exclusively found in the vacuole whereas one-fourth of raffinose was localized in the stroma. Apparently, the subcellular distribution of the RFOs differs because they fulfill different functions in plant metabolism during winter. Raffinose might function in protecting chloroplast membranes during freezing, whereas higher RFO oligomers may exert protective effects on vacuolar membranes. In addition, the high content of RFOs in winter leaves may also result from reduced consumption of assimilates.

The availability of glucose to CHO cells affects the intracellular lipid-linked oligosaccharide distribution, site occupancy and the N-glycosylation profile of a monoclonal antibody

The glycosylation pattern of a chimeric heavy chain antibody (EG2) produced from CHO cells was affected by the glucose concentration (0–25mM) of cultures established at high density (>106ml–1) over 24h. The resulting proportion of non-glycosylated Mab was directly correlated to the exposure time of cells to media depleted of glucose. Deprivation of glucose for the full 24h resulted in a 45% non-glycosylated Mab fraction.Analysis of steady state levels of intracellular lipid-linked oligosaccharides (LLOs) showed that under glucose limitation there was a reduction in the amount of full length LLO (Glc3Man9GlcNac2), with a concomitant increase in the smaller mannosyl-glycans (Man2–5GlcNAc2). Glycan microheterogeneity was quantified by galactosylation and sialylation indices (GI and SI) which showed a direct correlation to the cell specific glucose uptake. The GI increased to 0.83 following media supplementation with a cocktail of uridine, manganese and galactose. This is significantly higher than for a fully humanized antibody (DP12) produced under the similar conditions or for similar antibodies reported in the literature. The high GI of the chimeric antibody (EG2) may be due to its low molecular weight and unusual structure. These findings are important in relation to the low substrate that may occur in fed-batch cultures for Mab production.

Evaluation of diethylenetriaminepentaacetic acid–manganese(II) complexes modified by narrow molecular weight distribution of chitosan oligosaccharides as potential magnetic resonance imaging contrast agents

Novel conjugates of narrow molecular weight distribution of chitosan oligosaccharides (CSn; n=6, 8, 11) with manganese–diethylenetriaminepentaacetic acid (Mn–DTPA) as potential magnetic resonance imaging (MRI) contrast agents were synthesized. The structures were characterized by means of Fourier transform infrared spectra, 13C nuclear magnetic resonance, size exclusion chromatography and inductively coupled plasma atomic emission spectrometry. The characterization results showed that Mn–DTPA was successfully linked to aminated CSn by an amide function. The magnetic properties were characterized by in vitro and T1-weighted FLASH image experiments. Relaxivities studies indicated that Mn–DTPA–CSn (n=8, 11) provided higher relaxivity, either in aqueous or bovine serum albumin solution (0.725 mM), than commercial contrast agent Gd–DTPA. The stability results showed that Mn–DTPA–CSn in aqueous were stable enough to prevent MnII ions from releasing. The preliminary in vitro and T1-weighted FLASH image studies suggested that Mn–DTPA–CSn had the advantage of becoming promising MRI contrast agents.

Dicalcin Inhibits Fertilization through Its Binding to a Glycoprotein in the Egg Envelope in Xenopus laevis

Fertilization comprises oligosaccharide-mediated sperm-egg interactions, including sperm binding to an extracellular egg envelope, sperm penetration through the envelope, and fusion with an egg plasma membrane. We show that Xenopus dicalcin, an S100-like Ca(2+)-binding protein, present in the extracellular egg envelope (vitelline envelope (VE)), is a suppressive mediator of sperm-egg interaction. Preincubation with specific antibody greatly increased the efficiency of in vitro fertilization, whereas prior application of exogenous dicalcin substantially inhibited fertilization as well as sperm binding to an egg and in vitro sperm penetration through the VE protein layer. Dicalcin showed binding to protein cores of gp41 and gp37, constituents of VE, in a Ca(2+)-dependent manner and increased in vivo reactivity of VE with a lectin, Ricinus communis agglutinin I, which was accounted for by increased binding ability of gp41 to the lectin and greater exposure of gp41 to an external environment. Our findings strongly suggest that dicalcin regulates the distribution of oligosaccharides within the VE through its binding to the protein core of gp41, probably by modulating configuration of oligosaccharides on gp41 and the three-dimensional structure of VE framework, and thereby plays a pivotal role in sperm-egg interactions during fertilization.

Glycoprofiling of the Human Salivary Proteome

Glycosylation is important for a number of biological processes and is perhaps the most abundant and complicated of the known post-translational modifications found on proteins. This work combines two-dimensional polyacrylamide gel electrophoresis (2-DE) and lectin blotting to map the salivary glycome, and mass spectrometry to identity the proteins that are associated with the glycome map. A panel of 15 lectins that recognize six sugar-specific categories was used to visualize the type and extent of glycosylation in saliva from two healthy male individuals. Lectin blots were compared to 2-D gels stained either with Sypro Ruby (protein stain) or Pro-Q Emerald 488 (glycoprotein stain). Each lectin shows a distinct pattern, even those belonging to the same sugar-specific category. In addition, the glycosylation profiles generated from the lectin blots show that most of the salivary proteins are glycosylated and that the pattern is more widespread than is demonstrated by the glycoprotein stained gel. Finally, the co-reactivity between two lectins was measured to determine the glycan structures that are most and least often associated with one another along with the population variation of the lectin reactivity for 66 individuals.

Effects of Eucalyptus globulus Wood Autohydrolysis Conditions on the Reaction Products

Eucalyptus globulus wood samples were reacted in aqueous media (hydrothermal treatments) at 160 degrees C for 30-66 min. Liquors from the several experiments were analyzed by spectrophotometry, high-performance liquid chromatography, or gas chromatography-mass spectrometry for monosaccharides, oligosaccharides, oligosaccharide substituents (arabinose moieties, uronic acids, and acetyl groups), acetic acid, furfural, hydroxymethylfurfural, and dichloromethane-soluble compounds. Individual components of this latter fraction were identified and quantified. The molecular weight distribution of oligosaccharides was studied by high-performance size exclusion chromatography. The kinetics of xylan conversion into high-, medium-, and low-molecular-weight products was assessed in terms of the severity factor and by pseudohomogeneous kinetic models.

Distribution of the glycoconjugate oligosaccharides in the human placenta from pregnancies complicated by altered glycemia: lectin histochemistry

The aim of this study was to investigate the distribution of the oligosaccharides of the glycoconjugates in placentas from pregnancies complicated by different degree of altered glycaemia. Placentas from women with physiological pregnancies (group 1), with pregnancies complicated by minor degree of glucose intolerance (group 2) and with pregnancies complicated by gestational diabetes mellitus (GDM) treated with insulin (group 3) were collected. Ten lectins were used (ConA, WGA, PNA, SBA, DBA, LTA, UEA I, GSL II, MAL II and SNA) in combination with chemical and enzymatic treatments. The data showed a decrease of sialic acid linked alpha(2-6) to galactose/N-acetyl-D-galactosamine and an increase of N-acetyl-D-glucosamine in the placentas of the pathological groups, in particular the group 3, comparing to the group 1. A decrease of L-fucose (LTA) and D-galactose-(beta1-3)-N-acetyl-D-galactosamine, and an increase and/or appearance of L-fucose (UEA I) and N-acetyl-D-galactosamine were observed in both the pathological groups, particularly in the group 2, with respect to the group 1. In GDM, and even in pregnancies with a simple alteration of maternal glycaemia, the changes in the distribution of oligosaccharides could be related to alteration of the structure and functionality of the placenta.

Determination of Molecular Weight Distribution and Average Molecular Weights of Oligosaccharides by HPLC with a Common C18 Phase and a Mobile Phase with High Water Content

Molecular weight distribution, Molecular weight determination, Oligosaccharides, ABEEderivatization, HPLCSize Exclusion Chromatography (SEC) has been exten-sively used to monitor molecular weight distribution ofpolymer samples. A typical phase of SEC is composed ofuniform-sized porous beads with pores of wide dispersity. Asolute whose size is larger than the largest pore of the phasewill elute first, and a solute whose size is smaller than thesmallest pore of the phase will elute last in SEC. In otherwords, the size factor governs elution order. Larger soluteswill elute faster than smaller solutes. SEC has been used in analysis of polysaccharides, too. Forexample, a review of SEC of cellulose and related poly-saccharides