Types Of Disaccharides Research Articles

Disaccharide-assisted inkjet freezing for improved cell viability

Non-permeable disaccharides are widely used as cryoprotectant agents due to their low cytotoxicity, but their protective effect is insufficient when the disaccharides are present only extracellularly. On the other hand, cryoprotectant agent (CPA)-free cryopreservation has been recently achieved by instantaneously inkjet-freezing cells as tiny droplets. However, CPA-free cryopreservation requires skilled handling operations due to instability of the vitreous water without the CPA. In this study, the effectiveness of separately adding two types of disaccharides in inkjet freezing of 3T3 cells was evaluated and the following results were obtained. First, trehalose showed the highest effect at 0.57 M, twice the plasma osmolarity, with a maximum cell viability of over 90 % when freezing 70 pL droplets. However, higher concentrations of trehalose decreased cell viability due to damage caused by dehydration. Similarly, sucrose gave cell viability close to 90 % at 0.57 M with 70 pL droplets, and higher concentrations decreased cell viability. Next, the relationship between minimum trehalose concentrations to prevent intracellular and extracellular ice crystal formation and droplet size was analyzed. The results indicated that trehalose of less than 0.57 M was able to inhibit intracellular ice crystal formation even in the largest droplet used in this study, 450 pL, while trehalose of nearly 0.57 M was required to inhibit extracellular ice crystal formation in the smallest droplet, 70 pL. In other words, the suppression of extracellular ice crystals by the addition of CPA was shown to be crucial in improving the viability of inkjet superflash freezing.

Osmosis dehydration of sweet corn (Zea mays saccharata.) kernel with trehalose solution

Osmosis dehydration is a process of reducing water content by immersing the material in a hypertonic solution. It usually uses a sugar solution likes mono-saccharide or disaccharide. Trehalose is one type of disaccharide that can be used as a solute. Trehalose is able to maintain the nutrition content of food material and the aroma of horticulture products because it maintains and stabilizes complex molecules. Immersing of sweet corn kernel in trehalose solution was expected to maintain kernel sweet corn quality in relation to the next process. The objective of the research is to investigate the effects of the different immersing temperatures and trehalose concentrations on the physical quality of sweet corn. This study used solution with concentrations of 4%, 8%, and 12% trehalose. The variations of immersing temperature were 30°C, 40°C, and 50°C. The experiment was done with a factorial completely randomized design. The first factor was immersing temperature and the second factor was the concentration of trehalose solution. The data was analyzed using Duncan Multiple Range Test (DMRT) method. The temperature treatment of 50°C and trehalose concentration of 12% showed the highest weight reduction (6.18%), solid gain (4.5%), and water loss (10.38%). The lowest water content of corn kernel was also obtained in this treatment i.e 78.7%.

Establishing a kinetic model of biomass-derived disaccharide hydrolysis over solid acid: A case study on hierarchically porous niobium phosphate

Macroscopic kinetic models were established to describe the overall hydrolysis process of disaccharides with different type of glycosidic bond and constituted monosaccharides over hierarchically porous niobium phosphate (NbP) aiming for evaluating reaction efficiency of saccharide hydrolysis over solid acid. The NbP sample was synthesized by a sol–gel method accompanied by phase separation with co-continuous macroporous structure and high P/Nb molar ratio. The synthesized NbP sample showed high catalytic performance in the hydrolysis of disaccharides in an aqueous solution. Sucrose with α(1 → 2) glycosidic bond was the most easily hydrolyzed, with almost 100% conversion and monosaccharide yield, followed by melibiose α(1 → 6) and maltose α(1 → 4), while cellobiose β(1 → 4) was the strongest against to be hydrolyzed. The kinetic analysis showed that the reaction order is 1.0 over all the substrates and varied from 0.45 to 0.82 over the acid site, depending on the type of disaccharide. The activation of the decomposition reaction was larger than that of hydrolysis reaction, indicating that decomposition is more sensitive to temperature change than hydrolysis. Accordingly, direct decomposition of the disaccharides and the constituent monosaccharides synergistically determined the final yield and selectivity of the monosaccharides. Further, the decomposition and dehydration of glucose and galactose were found to occur in the bulk aqueous solution instead of on the surface of NbP.

Disaccharide supplementation of extenders is an effective means of improving the cryopreservation of semen in sturgeon

Sperm damage can be alleviated by optimizing the types and levels of cryoprotectants (including sugars) added to the extender to protect the sperm cells during freezing. This study was conducted to elucidate the effect of different disaccharides (maltose, lactose, trehalose and lactulose) upon the motility parameters of cryopreserved semen and the post-thaw storage of semen from Persian sturgeon, Acipenser persicus and Beluga sturgeon, Huso huso. Semen samples were diluted 1:5 in 9% methanol containing 0.2M maltose, trehalose, lactose or lactulose. Then, semen was equilibrated for 10min on ice and submerged in liquid nitrogen. After thawing (40°C, 5s) semen was stored for 0, 15, 30 and 60min at 4°C and semen motility investigated. For both sturgeon, the type of disaccharide had no effect on the duration of semen motility (expressed as curvilinear velocity, VCL). From the four disaccharides tested, lactulose exhibited the lowest sperm percentage. Furthermore, for all four disaccharides, cryopreserved semen motility was not affected by storage times of up to 30min maximum; however, after 60min of storage, a significant reduction was observed. Consequently, the best results were achieved with the disaccharides featuring glucose in their composition. In other words, maltose, lactose and trehalose can be used successfully for the cryopreservation of sturgeon semen.

Mid-infrared spectroscopic analysis of saccharides in aqueous solutions with sodium chloride.

The infrared spectral characteristics of three different types of disaccharides (trehalose, maltose, and sucrose) and four different types of monosaccharides (glucose, mannose, galactose, and fructose) in aqueous solutions with sodium chloride (NaCl) were determined. The infrared spectra were obtained using the FT-IR/ATR method and the absorption intensities respected the interaction between the saccharide and water with NaCl were determined. This study also focused on not only the glycosidic linkage position and the constituent monosaccharides, but also the concentration of the saccharides and NaCl and found that they have a significant influence on the infrared spectroscopic characterization of the disaccharides in an aqueous solution with NaCl. The absorption intensities representing the interaction between a saccharide and water with NaCl were spectroscopically determined. Additionally, the applications of MIR spectroscopy to obtain information about saccharide-NaCl interactions in foods and biosystems were suggested.

Effect of Temperature on Triaxial Behavior of a Sand with Disaccharide

Disaccharides are carbohydrates consisting of two monosaccharides, currently introduced as soil improvement additives and an alternative material for identifying the structural behavior of a sand in small-scale model tests. In this experimental study, a type of disaccharide (i.e., sucrose) was used at two different temperatures to investigate the undrained triaxial compression testing of Leighton Buzzard Sand. The materials, specimen preparation and test methods are described, as are the results of a suite of triaxial tests in a temperature controlled cell in which deviatoric stress, pore water pressure and local strain were measured. The results describe unusual behavior involving deviatoric stress and pore water pressure jumps when employing a relatively higher temperature (60°C). However, the results suggest that specimens tested at room temperature (23°C) could suppress dilatancy without any jumps observed in deviatoric stress and pore water pressure.

Effects of the naturally-occurring disaccharides, palatinose and sucrose, on incretin secretion in healthy non-obese subjects.

Incretins might play some pathophysiological role in glucose metabolism in diabetes and obesity; it is not clear whether or not the amount and the pattern of incretin secretion vary with different types of sugars. To evaluate the effect of two types of disaccharides on glucose metabolism and the kinetics of incretin secretion, plasma levels were measured after palatinose or sucrose ingestion in non-obese healthy participants. The study was carried out on healthy participants who were given a solution containing 50g of palatinose or sucrose for ingestion. Blood samples were obtained before loading and after ingestion. Insulin, glucagon and incretins hormones were measured by the enzyme-linked immunosorbent assay method. When the data were compared between palatinose and sucrose ingestion, both plasma glucose values at 15, 30 and 60min, and plasma insulin values at 15 and 30min after palatinose loading were significantly lower than those after sucrose loading. Plasma levels of total glucose-dependent insulinotropic polypeptide at 15-90min after palatinose loading were significantly lower than those after sucrose loading. Plasma levels of total and active glucagon-like peptide-1 at 90min and the area under the curve (60-120min) of the total glucagon-like peptide-1 were significantly higher with palatinose-loading than with sucrose loading. Compared with sucrose, palatinose appears to have a more favorable effect on glucose metabolism and protection of pancreatic islets as a result of less hyperglycemic and hyperinsulinemic potency.

Stabilizing Effect of Four Types of Disaccharide on the Enzymatic Activity of Freeze-dried Lactate Dehydrogenase: Step by Step Evaluation from Freezing to Storage

In order to understand the stabilizing effects of disaccharides on freeze-dried proteins, the enzymatic activity of lactate dehydrogenase (LDH) formulations containing four types of disaccharide (trehalose, sucrose, maltose, and lactose) at two relative humidity (RH) levels (about 0 and 32.8%) was investigated after three processes: freeze-thawing, freeze-drying, and storage at three temperatures (20, 40, and 60 degrees C) above and/or below the glass transition temperature (T(g)). The enzymatic activity was determined from the absorbance at 340 nm, and T(g) of the samples was investigated by differential scanning calorimetry. At each RH condition, T(g) values of sucrose formulations were lower than those of other formulations. Although effects of the disaccharides on the process stability of LDH were comparable, storage stability was dependent on the type of disaccharide. All the formulations were destabilized significantly during storage at temperature above T(g). During storage at temperature below T(g), the LDH activity decreased with increases in the storage temperature and moisture. Maltose and lactose formulations showed significant destabilization with the change of color to browning. Taking the storage stability of freeze-dried proteins under the various conditions (temperature and RH) into consideration, trehalose is better suited as the stabilizer than other disaccharides.

Enzymatic synthesis of myristoyl disaccharides and their surface activity

AbstractThe condensation of trehalose, maltose, cellobiose, sucrose, turanose, palatinose, lactose and melibiose with myristic acid by a lipase (triacylglycerol acylhydrolase; EC 3.1.1.3) from Candida antarctica was examined at 60 °C in a mixture of pyridine and 2‐methyl‐2‐propanol (20/80 by vol.). The reactivity of trehalose was the highest among the tested disaccharides, and maltose and palatinose followed. Cellobiose and lactose were poor substrates for condensation. Condensation of all the disaccharides except for cellobiose and lactose with myristic acid was carried out at various initial disaccharide concentrations to estimate the initial reaction rate. Plots of the initial rates for monomyristoyl disaccharide formation versus the initial disaccharide concentration normalized by the solubility of the disaccharide in the mixture indicated that palatinose was the best substrate, and that trehalose, turanose and maltose were the next best ones. The surface activity of the monoacyl disaccharides scarcely depended on the type of disaccharide. Copyright © 2007 Society of Chemical Industry

Influences of Monosaccharides and its Glycosidic Linkage on Infrared Spectral Characteristics of Disaccharides in Aqueous Solutions

The infrared spectral characteristics of ten different types of disaccharides (trehalose, kojibiose, nigerose, maltose, isomaltose, trehalulose, sucrose, turanose, maltulose, and palatinose) and five different types of monosaccharides (glucose, mannose, galactose, talose, and fructose) in aqueous solutions (H2O and D2O) were determined. The infrared spectra were collected using the Fourier transform infrared attenuated total reflectance (FT-IR/ATR) method and comparisons between the degrees of absorption band-shift of the saccharide spectra in the H2O solution with those in the D2O solution with respect to the saccharide concentrations were done. The study revealed that the wavenumber shifts in the bands of mono- and disaccharides in the H2O and D2O solutions could be used as an indicator of the level of interaction between the saccharides and water. The study also focused on the glycosidic linkage position and the constituent monosaccharides and found that they have a significant influence on the infrared spectroscopic characterization of disaccharides in an aqueous solution.

Silver Complexation and Tandem Mass Spectrometry for Differentiation of Isomeric Flavonoid Diglycosides

For detection and differentiation of isomeric flavonoids, electrospray ionization mass spectrometry is used to generate silver complexes of the type (Ag + flavonoid)+. Collisionally activated dissociation (CAD) of the resulting 1:1 silver/flavonoid complexes allows isomer differentiation of flavonoids. Eighteen flavonoid diglycosides constituting seven isomeric series are distinguishable from each other based on the CAD patterns of their silver complexes. Characteristic dissociation pathways allow identification of the site of glycosylation, the type of disaccharide (rutinose versus neohesperidose), and the type of aglycon (flavonol versus flavone versus flavanone). This silver complexation method is more universal than previous metal complexation methods, as intense silver complexes are observed even for flavonoids that lack the typical metal chelation sites. To demonstrate the feasibility of using silver complexation and tandem mass spectrometry to characterize flavonoids in complex mixtures, flavonoids extracted from grapefruit juice are separated by high-performance liquid chromatography and analyzed via a postcolumn complexation ESI-MS/MS strategy. Diagnostic fragmentation pathways of the silver complexes of the individual eluting flavonoids allow successful identification of the six flavonoids in the extract.

Threshold dissociation and molecular modeling of transition metal complexes of flavonoids

The relative threshold dissociation energies of a series of flavonoid/transition metal/auxiliary ligand complexes of the type [MII (flavonoid - H) auxiliary ligand]+ formed by electrospray ionization (ESI) were measured by energy-variable collisionally activated dissociation (CAD) in a quadrupole ion trap (QIT). For each of the isomeric flavonoid diglycoside pairs, the rutinoside (with a 1-6 inter-saccharide linkage) requires a greater CAD energy and thus has a higher dissociation threshold than its neohesperidoside (with a 1-2 inter-saccharide linkage) isomer. Likewise, the threshold energies of complexes containing flavones are higher than those containing flavanones. The monoglycoside isomers also have characteristic threshold energies. The flavonoids that are glycosylated at the 3-O- position tend to have lower threshold energies than those glycosylated at the 7-O- or 4'-O- position, and those that are C- bonded have lower threshold energies than the O- bonded isomers. The structural features that substantially influence the threshold energies include the aglycon type (flavanone versus flavone), the type of disaccharide (rutinose versus neohesperidose), and the linkage type (O- bonded versus C- bonded). Various computational means were applied to probe the structures and conformations of the complexes and to rationalize the differences in threshold energies of isomeric flavonoids. The most favorable coordination geometry of the complexes has a plane-angle of about 62 degrees , which means that the deprotonated flavonoid and 2,2'-bipyridine within a complex do not reside on the same plane. Stable conformations of five cobalt complexes and five deprotonated flavonoids were identified. The conformations were combined with the point charges and helium accessible surface areas to explain qualitatively the differences in threshold energies for isomeric flavonoids.

Hydrolysis of disaccharides containing glucose residue in subcritical water

The hydrolysis of disaccharides consisting of two glucose residues or of glucose and fructose or galactose residues in subcritical water was measured using a tubular reactor at 10 MPa and 180–260 °C. The relationship between the fraction of remaining disaccharide and the residence time could be expressed by the Weibull equation for all the disaccharides tested at any temperature. The susceptibility to hydrolysis largely depended on the type of disaccharide, and it was found that the electrostatic potential charge of a glucosidic oxygen atom was an indication for the susceptibility of disaccharide to the hydrolysis. It was also shown that the enthalpy–entropy compensation held for the hydrolysis of disaccharides in subcritical water.

Hydroxymethyl Rotamer Populations in Disaccharides.

Sixteen methyl glucopyranosyl glucopyranoside disaccharides (methyl beta-d-Glcp(p-Br-Bz)-(1-->x)-beta/alpha-d-Glcp) containing beta-glycosidic linkages (1-->2, 1-->3, 1-->4, and 1-->6) were synthesized and analyzed by means of CD and NMR spectroscopy in three different solvents. For each of these four types of disaccharides, a correlation was observed between the hydroxymethyl rotational populations around the C5-C6 bond of the glucopyranosyl residue II with the substituents and the anomeric configuration of the methoxyl group in residue I, as well as with the solvent. Nonbonded interactions, the stereoelectronic exo-anomeric effect, and hydrogen bonding were found to be responsible for the observed rotameric differences. Whereas the rotational populations of the (1-->6)-linked disaccharides are mainly dependent on the exo-anomeric effect, the (1-->2)-bonded disaccharides are strongly dependent on the anomeric configuration at C1, and the (1-->3)- and (1-->4)-linked disaccharides are mainly dependent on the substituents and the solvent. The population of the gt rotamer decreases as nonbonded interactions increase but increases as the exo-anomeric effect becomes greater, as well as in the presence of intramolecular hydrogen bonding to the endocyclic oxygen O5'. Comparison of the hydroxymethyl rotational preferences between our model disaccharides revealed a dependence on the glycosidic linkage type. Thus the population of the gg and gt rotamers decreases/increases from (1-->2)- (beta series), to (1-->6)-, to (1-->2)- (alpha series), to (1-->4)-, and to (1-->3)-bonded disaccharides respectively, while the tg rotamer population remains almost constant (around 20%), except for the (1-->3)- and (1-->4)-linked disaccharides with the intramolecular hydrogen bonding to O5', where this population decreases to 10%.

Molecular Dynamics Simulation of Neocarrabiose 2,4′-Bis(sulfate) and Carrabiose 4′,2-Bis(sulfate) as Building Blocks of ι-Carrageenan in Water

Abstract Molecular mechanics and molecular dynamics simulations were performed on two types of disaccharides, neocarrabiose 2,4′-bis(sulfate) and carrabiose 4′,2-bis(sulfate), which are building blocks of ι-carrageenan. Although the conformation and potential-energy surfaces of these disaccharides have been investigated by several researchers, all of them were analyzed using a vacuum calculation. To investigate the conformational behavior of these molecules in water, we performed a molecular dynamics simulation with the presence of explicit water molecules and counter ions around the disaccharides. The trajectories of the glycosidic dihedral angles in the water simulation reproduced the potential-energy surface calculated not with a dielectric constant of 80, but with 1. The electrostatic force was found to act so as to restrict the allowed area of the potential-energy surfaces. The most stable conformation of neocarrabiose 2,4′-bis(sulfate) is φ = 162, ψ = 174. Although the global minimum conformation of carrabiose 4′,2-bis(sulfate) is at A1 (φ = 176° and ψ = −166°), the molecular dynamics simulation in water suggested that the structure, B1 (φ = 164° and ψ = −87°), is more stable than A1 by analyzing the trajectory and the hydrogen bonds with water molecules. This indicates that it is important for the conformational analysis to take into account the solvation effect explicitly. The structure of B1 agrees with that found by an NMR experiment.

Dermatan sulfates of normal and scarred fascia

We evaluated the composition of dermatan sulfates (DS) derived from 23 samples of normal and 23 samples of scarred fascia lata. We analyzed the molecular weight of intact DS chains and the length of chain regions comprising: (1) clusters of l-iduronate-containing disaccharides (‘iduronic sections’); (2) clusters of d-glucuronate-containing disaccharides (‘glucuronic sections’); and (3) copolymeric sections with both types of disaccharides. A portion of scarred fascia DS chains demonstrated higher molecular weight compared with those from normal tissue. Most disaccharides of DS chains derived from both fascia types form copolymeric segments — heterogeneous in size — with alternatively distributed single disaccharides with glucuronic residues and mainly single ones with iduronate. Only a small number of disaccharides form ‘glucuronic sections’ of heterogeneous size or short ‘iduronic sections’. However, the scarred fascia DS chains demonstrate an increased content of shorter ‘glucuronic sections’ and shorter, often oversulfated, copolymeric segments. It seems that in normal fascia, the DS chain type with a single, long copolymeric region and a single, shorter ‘glucuronic section’ is predominant, while in scarred tissue an increase in multidomain DS chain content may occur.

Defining carbohydrate specificity of Ricinus communis agglutinin as Ga1 β 1 → 4GlcNAc ( II) > Gal β 1 → 3GlcNAc ( I) > Gal α 1 → 3Gal ( B) > Gal β 1 → 3GalNAc ( T)

To define carbohydrate specificity of Ricinus communis agglutinin (RCA 1), the combining site of RCA 1 was further characterized by quantitative precipitin (QPA) and precipitin-inhibition assays (QPIA). Among the oligosaccharides tested for QPIA, Gal β 1 → 4GlcNAc ( II, human blood group type II precursor sequence) was found to be 7.1 times more active than Gal β 1 → 3GalNAc ( T, Thomsen-Friedenreich sequence) and about 1.7 times more active than the other three disaccharides tested — Gal β 1 → 4Man, Gal β 1 → 3 dAra and Gal β 1 → 6GalNAc. Gal α 1 → 4Gal, the receptor of the uropathogenic E. coli ligand was 3.6 times less active than the II sequence. These results indicate that the β 1 →4 linkage of the terminal Gal to subterminal GlcNAc is important as this β 1 → 4GlcNAc sequence is at least 1.6 times more active than other types of disaccharides. Among the glycoproteins examined for QPA, native and desialized bovine submandibular glycoproteins, native and desialized human plasma α 1-acid glycoproteins, as well as crude hog stomach mucin and its three mild acid hydrolyzed products reacted well with the lectin. These glycoproteins precipitated over 75% of the lectin nitrogen added indicating that RCA 1 has the ability to recognize Gal β 1 → 4 3 GlcNAc and/or the related residues at the non-reducing ends and at positions in the interior of the chains. However, Tn (GalNAc α 1 → Ser/Thr sequence) rich glycoproteins such as desialized ovine submandibular glycoprotein and desialized armadillo salivary glycoprotein, in which over 90% of the carbohydrate side chains are Tn determinants with none or only a trace of I/II or T determinants, precipitated poorly with RCA 1. From the present and previous results obtained, the carbohydrate specificity of RCA 1 can be constructed and summarized in decreasing order by lectin determinants as follows: II (Gal β 1 → 4GlcNAc) > I (Gal β 1 → 3GlcNAc) > E (Gal α 1 → 4Gal) and B (Gal α 1 → 3Gal) > T (Gal β 1 → 3GalNAc), while Tn (GalNAc α 1 → Ser/Thr) is a poor inhibitor.