Content: | 10 mg |
Shipping Temperature: | Ambient |
Storage Temperature: | Ambient |
Physical Form: | Powder |
Stability: | > 2 years under recommended storage conditions |
CAS Number: | 49694-21-5 |
Molecular Formula: | C30H50O25 |
Molecular Weight: | 810.7 |
Purity: | > 95% |
Substrate For (Enzyme): | endo-1,4-β-Xylanase |
High purity Xylohexaose for use in research, biochemical enzyme assays and in vitro diagnostic analysis.
McCleary, B. V. & McGeough, P. (2015). Appl. Biochem. Biotechnol., 177(5), 1152-1163.
The most commonly used method for the measurement of the level of endo-xylanase in commercial enzyme preparations is the 3,5-dinitrosalicylic acid (DNS) reducing sugar method with birchwood xylan as substrate. It is well known that with the DNS method, much higher enzyme activity values are obtained than with the Nelson-Somogyi (NS) reducing sugar method. In this paper, we have compared the DNS and NS reducing sugar assays using a range of xylan-type substrates and accurately compared the molar response factors for xylose and a range of xylo-oligosaccharides. Purified beechwood xylan or wheat arabinoxylan is shown to be a suitable replacement for birchwood xylan which is no longer commercially available, and it is clearly demonstrated that the DNS method grossly overestimates endo-xylanase activity. Unlike the DNS assay, the NS assay gave the equivalent colour response with equimolar amounts of xylose, xylobiose, xylotriose and xylotetraose demonstrating that it accurately measures the quantity of glycosidic bonds cleaved by the endo-xylanase. The authors strongly recommend cessation of the use of the DNS assay for measurement of endo-xylanase due to the fact that the values obtained are grossly overestimated due to secondary reactions in colour development.
Hide AbstractVersatile high resolution oligosaccharide microarrays for plant glycobiology and cell wall research.
Pedersen, H. L., Fangel, J. U., McCleary, B., Ruzanski, C., Rydahl, M. G., Ralet, M. C., Farkas, V., Von Schantz, L., Marcus, S. E., Andersen, M.C. F., Field, R., Ohlin, M., Knox, J. P., Clausen, M. H. & Willats, W. G. T. (2012). Journal of Biological Chemistry, 287(47), 39429-39438.
Microarrays are powerful tools for high throughput analysis, and hundreds or thousands of molecular interactions can be assessed simultaneously using very small amounts of analytes. Nucleotide microarrays are well established in plant research, but carbohydrate microarrays are much less established, and one reason for this is a lack of suitable glycans with which to populate arrays. Polysaccharide microarrays are relatively easy to produce because of the ease of immobilizing large polymers noncovalently onto a variety of microarray surfaces, but they lack analytical resolution because polysaccharides often contain multiple distinct carbohydrate substructures. Microarrays of defined oligosaccharides potentially overcome this problem but are harder to produce because oligosaccharides usually require coupling prior to immobilization. We have assembled a library of well characterized plant oligosaccharides produced either by partial hydrolysis from polysaccharides or by de novo chemical synthesis. Once coupled to protein, these neoglycoconjugates are versatile reagents that can be printed as microarrays onto a variety of slide types and membranes. We show that these microarrays are suitable for the high throughput characterization of the recognition capabilities of monoclonal antibodies, carbohydrate-binding modules, and other oligosaccharide-binding proteins of biological significance and also that they have potential for the characterization of carbohydrate-active enzymes.
Hide AbstractEffects of cellulose and lignin on xylooligosaccharides production from xylan: The superiority of acetic acid/sodium acetate hydrolysis.
Liao, H., Chen, Z., Wen, P., Ying, W. & Zhang, J. (2023). Industrial Crops and Products, 205, 117497.
Xylooligosaccharides (XOS) are high-value products derived from xylan in lignocellulose and have a variety of prebiotic applications. The intertwining of xylan, cellulose, and lignin in lignocelluloses may affect XOS production. In order to investigate those impacts, the comparative analysis of XOS production was conducted using corncob, poplar and xylan as substrates through the hydrolysis using acetic acid/sodium acetate (AC/SA), acetic acid (AC), and pure water. The results revealed that the hydrolysis of different feedstocks using AC/SA generated the highest XOS yield and the least by-products compared to AC hydrolysis and hydrothermal (HT) treatment. The presence of cellulose led to the reductions of XOS production from xylan by AC/SA hydrolysis, AC hydrolysis, and HT treatment by 6.6%, 6.3%, and 4.3%, respectively. The presence of cellulose and lignin largely decreased XOS yields by 22.2%, 22.0%, and 88.5%, respectively. Obviously, the cellulose slightly inhibited xylan hydrolysis, while lignin had a strong negative effect on xylan hydrolysis. Besides, the adverse effect of lignin on xylan hydrolysis was the greatest in HT treatment. Despite the presence of cellulose and lignin, AC/SA hydrolysis exhibited the superior ability in XOS production and reduced the formation of by-products compared to AC hydrolysis and HT treatment.
Hide AbstractValorization of rice husk by hydrothermal processing to obtain valuable bioproducts: Xylooligosaccharides and Monascus biopigment.
Centeno, A. C., Muñoz, S. S., Gonçalves, I. S., Vera, F. P. S., Forte, M. B. S., da Silva, S. S., dos Santos, J. C. & Hilares, R. T. (2023). Carbohydrate Polymer Technologies and Applications, 6, 100358.
Rice husk is a readily available residue which can be used for producing bioproducts in a biorefinery context. In this study, the hemicellulose fraction was hydrolyzed in a hydrothermal process to produce xylooligosaccharides (XOS), whereas the cellulosic hydrolysate was used for red pigment production by Monascus ruber Tieghem IOC 2225. The highest XOS (X2-X4) production (24 g per 1 kg of rice husk) was achieved at 180°C for 68 min in a non-stirred Parr reactor (50 mL). Subsequently, using a stirred parr reactor (1 L) at 180 °C for 60 min, 40 g of XOS (42% of xylobiose, 35% of xylobiose, 13% of xylotriose, 7% of xylotetraose, and 3% of xylopentaose) per 1 kg of rice husk were obtained. The XOS was then purified by using ultrafiltration (UF) with two diafiltration membranes at 6.5 pH, recovering approximately 92% of total XOS. Further purification was conducted with nanofiltration (NF) at 3.8 pH, recovering approximately 86.4% of XOS in the retentate. This process yielded XOS with a purity of 77%. Additionally, the enzymatic process yielded 132 g/kg of sugar, and the hydrolysate was used to produce 2.1 UA490nm of red pigment by fungi after 7 days.
Hide AbstractA novel class of xylanases specifically degrade marine red algal β1, 3/1, 4-mixed-linkage xylan.
Zhao, F., Yu, C. M., Sun, H. N., Zhao, L. S., Ding, H. T., Cao, H. Y., Chen, Y., Qin, Q., Zhang, Y. Z. & Chen, X. L. (2023). Journal of Biological Chemistry, 299(9), 105116.
Xylans are polysaccharides composed of xylose and include β1,4-xylan, β1,3-xylan, and β1,3/1,4-mixed-linkage xylan (MLX). MLX is widely present in marine red algae and constitutes a significant organic carbon in the ocean. Xylanases are hydrolase enzymes that play an important role in xylan degradation. While a variety of β1,4-xylanases and β1,3-xylanases involved in the degradation of β1,4-xylan and β1,3-xylan have been reported, no specific enzyme has yet been identified that degrades MLX. Herein, we report the characterization of a new MLX-specific xylanase from the marine bacterium Polaribacter sp. Q13 which utilizes MLX for growth. The bacterium secretes xylanases to degrade MLX, among which is Xyn26A, an MLX-specific xylanase that shows low sequence similarities (<27%) to β1,3-xylanases in the glycoside hydrolase family 26 (GH26). We show that Xyn26A attacks MLX precisely at β1,4-linkages, following a β1,3-linkage toward the reducing end. We confirm that Xyn26A and its homologs have the same specificity and mode of action on MLX, and thus represent a new xylanase group which we term as MLXases. We further solved the structure of a representative MLXase, AlXyn26A. Structural and biochemical analyses revealed that the specificity of MLXases depends critically on a precisely positioned β1,3-linkage at the −2/−1 subsite. Compared to the GH26 β1,3-xylanases, we found MLXases have evolved a tunnel-shaped cavity that is fine-tuned to specifically recognize and hydrolyze MLX. Overall, this study offers a foremost insight into MLXases, shedding light on the biochemical mechanism of bacterial degradation of MLX.
Hide AbstractTwo-Step Hydrothermal Pretreatments for Co-Producing Xylooligosaccharides and Humic-like Acid from Vinegar Residue.
Jiao, N., Zhu, Y., Li, H., Yu, Y., Xu, Y. & Zhu, J. (2023). Fermentation, 9(7), 589.
This study proposes an efficient strategy for co-producing high-value-added xylooligosaccharides (XOS) and humic-like acid (HLA) from vinegar residue based on two-step hydrothermal pretreatments. During the first-step hydrothermal pretreatment (170°C, 50 min), 29.1% of XOS (X2-X6) was obtained. The XOS yield was further improved to 36.2% with endoxylanase hydrolysis, thereby increasing the value of (X2-X4)/XOS from 0.8 to 1.0. Subsequently, the second-step hydrothermal pretreatment was investigated to produce HLA from the solid residue of the first-step hydrothermal pretreatment. The highest HLA yield was 15.3% in the presence of 0.6 mol/L of KOH at 210°C for 13 h. In addition, 31.7% of hydrochar by-product was obtained. The mass balance results showed that 1000 g of vinegar residue produced 67.9 g of XOS, 91.6 g of HLA, and 189.5 g of hydrochar. Therefore, this study provides a promising pathway for comprehensive use of lignocellulosic biomass in producing XOS and HLA.
Hide AbstractThe secretome of Agaricus bisporus: temporal dynamics of plant polysaccharides and lignin degradation.
Duran, K., Magnin, J., America, A. H., Peng, M., Hilgers, R., de Vries, R. P., Baars, J. J. P., Berkel, W. J. H., Kuyper, T. W. & Kabel, M. A. (2023). iScience, 26(7): 107087.
Despite substantial lignocellulose conversion during mycelial growth, previous transcriptome and proteome studies have not yet revealed how secretomes from the edible mushroom Agaricus bisporus develop and whether they modify lignin models in vitro. To clarify these aspects, A. bisporus secretomes collected throughout a 15-day industrial substrate production and from axenic lab-cultures were subjected to proteomics, and tested on polysaccharides and lignin models. Secretomes (day 6-15) comprised A. bisporus endo-acting and substituent-removing glycoside hydrolases, whereas β-xylosidase and glucosidase activities gradually decreased. Laccases appeared from day 6 onwards. From day 10 onwards, many oxidoreductases were found, with numerous multicopper oxidases (MCO), aryl alcohol oxidases (AAO), glyoxal oxidases (GLOX), a manganese peroxidase (MnP), and unspecific peroxygenases (UPO). Secretomes modified dimeric lignin models, thereby catalyzing syringylglycerol-β-guaiacyl ether (SBG) cleavage, guaiacylglycerol-β-guaiacyl ether (GBG) polymerization, and non-phenolic veratrylglycerol-β-guaiacyl ether (VBG) oxidation. We explored A. bisporus secretomes and insights obtained can help to better understand biomass valorization.
Hide AbstractDPPH radical scavenging activity of xylo-oligosaccharides mixtures of controlled composition: A step forward in understanding structure-activity relationship.
Fuso, A., Dejonghe, W., Cauwenberghs, L., Rosso, G., Rosso, F., Manera, I. & Caligiani, A. (2023). Journal of Functional Foods, 101, 105417.
Antioxidant activity of oligosaccharides is very discussed, and the relationship between their chemical structure and functionality is not clear. In this work, XOS, with different degrees of polymerization, acetylation and purity were produced starting from commercial xylans by enzymatic hydrolysis coupled with tangential ultrafiltration. A purified mixture containing DP 6-9 XOS was also produced. A detailed molecular characterization of all the XOS mixtures was performed by LC-MS, HPSEC-RID and 1H NMR. In vitro antioxidant activity was then tested against the stable DPPH free-radical. It was found that standard pure xylose and DP 2-6 XOS had very low scavenging capacity, while DP 6-9 XOS had a great one. In general, unsubstituted XOS are more antioxidant than acetylated ones, and a higher DP favours an increase in this functionality at first, then a decrease when molecular weights become higher.
Hide AbstractOrganosolv pretreatment of corncob for enzymatic hydrolysis of Xylan.
Buyukkileci, A. O. & Temelli, N. (2023). Biomass Conversion and Biorefinery, 1-10.
Xylan is a renewable polysaccharide, readily available in agricultural and forestry residues. It can be hydrolyzed to produce xylooligosaccharides (XOS) with prebiotic activity and xylose, a precursor for several industrial chemicals. Enzymatic hydrolysis of xylan in the lignocellulosic biomass to obtain xylose and XOS requires a pretreatment to facilitate xylanase activity. In this study, organosolv was evaluated for the delignification of corncob while retaining xylan in the pretreated biomass. The treatment at 170°C for 1 h with 70% ethanol provided 50% lignin removal and 81% xylan recovery. Increasing temperatures and decreasing ethanol fractions decreased the pH and the xylan recovery. Loss of xylan in the organosolv at 190°C and in the liquid hot water treatment could be prevented by the addition of 100 mM MgO, without compromising lignin removal. Pretreated corncob was suspended in citrate buffer and hydrolyzed by commercial xylanases. Accellerase XY (250 U/ml) at pH 5.5 and 55°C and Econase XT (0.6 U/ml) at pH 6.0 and 70°C provided around 65% xylan digestibility and generated xylose (9.8 g/l) and XOS (10.9 g/l), respectively. This approach could decrease xylan loss and degradation in the pretreatment step and yield clear hydrolysates composed of essentially xylose or XOS. Lignocellulosic biorefineries can benefit from the efficient utilization of xylan, increasing sustainability.
Hide AbstractIn Vitro Assessment of the Prebiotic Potential of Xylooligosaccharides from Barley Straw.
Álvarez, C., González, A., Ballesteros, I., Gullón, B. & Negro, M. J. (2023). Foods, 12(1), 83.
Barley straw was subjected to hydrothermal pretreatment (steam explosion) processing to evaluate its potential as a raw material to produce xylooligosaccharides (XOS) suitable for use as a prebiotic. The steam explosion pretreatment generated a liquid fraction containing solubilised hemicellulose. This fraction was purified using gel permeation chromatography to obtain a fraction rich in XOS DP2-DP6. The sample was characterised through analytical techniques such as HPAEC-PAD, FTIR and MALDI-TOF-MS. The prebiotic activity was evaluated using in vitro fermentation in human faecal cultures through the quantification of short-chain fatty acid (SCFA) and lactate production, the evolution of the pH and the consumption of carbon sources. The total SCFA production at the end of fermentation (30 h) was 90.1 mM. Positive significant differences between the amount of XOS from
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