β-D-Xylp-(1-4)-β-D-Xylp-(1-4)-D-Xyl | 47592-59-6

• 物质功能分类: 分析化学 - 标准品 - 药典标准品和杂质标准品
• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: β-D-Xylp-(1-4)-β-D-Xylp-(1-4)-D-Xyl
• 英文别名: xylotriose；Xylotriose；(2R,3R,4R)-4-(((2S,3R,4R,5R)-3,4-Dihydroxy-5-(((2S,3R,4S,5R)-3,4,5-trihydroxytetrahydro-2H-pyran-2-yl)oxy)tetrahydro-2H-pyran-2-yl)oxy)-2,3,5-trihydroxypentanal；(2R,3R,4R)-4-[(2S,3R,4R,5R)-3,4-dihydroxy-5-[(2S,3R,4S,5R)-3,4,5-trihydroxyoxan-2-yl]oxyoxan-2-yl]oxy-2,3,5-trihydroxypentanal
• CAS: 47592-59-6
• 化学式: C₁₅H₂₆O₁₃
• 分子量: 414.364
• InChiKey: ABKNGTPZXRUSOI-JFMIBIRXSA-N

物化性质

• 熔点：
  204-206°C
• 比旋光度：
  -38.2 º (c=0.5% in H2O);-48 º (c=1% in H2O)
• 沸点：
  767.6±60.0 °C(Predicted)
• 密度：
  1.68±0.1 g/cm3(Predicted)
• 溶解度：
  DMSO（少许）、水（少许）

计算性质

• 辛醇/水分配系数(LogP)：
  -5.9
• 重原子数：
  28
• 可旋转键数：
  8
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.93
• 拓扑面积：
  216
• 氢给体数：
  8
• 氢受体数：
  13

安全信息

• 安全说明：
  S24/25
• 海关编码：
  29400090

制备方法与用途

背景及概述

木聚糖是半纤维素的主要成分，是一种多聚五碳糖，约占细胞干重的15%-35%，在自然界中除纤维素外是最为丰富的可再生资源之一。其结构复杂，完全降解需多种酶共同参与，其中β-1,4内切木聚糖酶是主要的降解酶，能将木聚糖主链分解成不同长度的寡糖。

低聚木糖（也称木寡糖）是由2至7个木糖通过β（1→4）糖苷键连接而成的低聚糖。其聚合度通常在2-7之间，主要由水解木聚糖得到木二糖和木三糖构成。低聚木糖甜度约为蔗糖的一半，且口感纯正。它能选择性地增殖双歧杆菌，在降低胆固醇、维持肠道健康及促进钙吸收方面具有重要作用。

理化特性

与其他低聚糖相比，低聚木糖中木三糖的稳定性较好。在pH 2.5至8.0范围内加热1小时后无明显变化。在这一pH范围内的几乎所有食品体系中，木三糖都能保持良好的稳定性。即使在37℃下保存两个月，其在pH 2.5、7.0和8.0时的残留率分别为99.6%、99.1%和97.9%。研究表明，在室温下储存含低聚木糖饮料一年后，其保留量可达97%以上。因此，低聚木糖对热和酸都具有很高的稳定性，可在各种食品中广泛使用。

药代动力学

低聚木糖难以被人体消化酶系统分解。唾液、胃液、胰液和小肠液的消化试验均未能有效分解低聚木糖，因此其能量值很低或为零。

制备方法

采用凝胶过滤层析技术制备高纯度木二糖和木三糖：使用聚丙烯酰胺凝胶（Bio-Gel P-2）作为层析介质，借助快蛋白液相层析系统（FPLC），用脱气高纯水洗脱。实验步骤如下：

1. 以60mL/h的流速对低聚木糖混合液进行层析分离。
2. Bio-Gel P-2将低聚木糖混合液分离为多个级分，结果如图所示。
3. 分析峰4（洗脱体积772-812mL）和峰5（洗脱体积722-752mL）的不同级分。分析结果显示：峰4中主要成分为木二糖，含量在84.8%-98.5%之间，还含有少量的木三糖、葡萄糖或阿拉伯糖；而峰5以木三糖为主，含量为80.3%-89.7%，此外还含有少量的木二糖和木糖。
4. 多次收集并浓缩上述级分后进行HPLC分析，结果显示其纯度分别为：木二糖95.6%、木三糖83.4%。

主要参考资料

1. 佘元莉等（2010）. 具高木二糖和木三糖形成活力木聚糖酶的链霉菌鉴定. 食品工业科技, 190-193.
2. 郑建仙（编著，2001）. 低能量食品. 北京：中国轻工业出版社. 第147-148页.
3. 张军华等（2005）. 木二糖和木三糖的分离及其用于双歧杆菌的体外培养. 林产化学与工业, 25(1):15-18.

生物活性

Xylotriose是一种天然的木寡糖底物，可以被Selenomonas ruminantium SXA来源的催化有效的β-D-木糖苷酶水解。

反应信息

• 作为反应物：
  描述：

  β-D-Xylp-(1-4)-β-D-Xylp-(1-4)-D-Xyl 在 sodium hydroxide 作用下， 生成 D,L-3-deoxy-2-C-hydroxymethyltetrono-1,4-lactone
  参考文献：
  名称：

  Aspinall et al., Journal of the Chemical Society, 1956, p. 4807,4809

  摘要：

  DOI：
• 作为产物：
  描述：

  xylohexaose 在 polyethylenimine-coated Selenomonas ruminantium β-xylosidase immobilized on glyoxyl agarose 、 水 作用下， 以 aq. acetate buffer 为溶剂， 反应 2.08h， 生成 β-D-Xylp-(1-4)-β-D-Xylp-(1-4)-D-Xyl
  参考文献：
  名称：

  β-xylosidase from Selenomonas ruminantium: Immobilization, stabilization, and application for xylooligosaccharide hydrolysis

  摘要：

  The tetrameric -xylosidase from Selenomonas ruminantium is very stable in alkaline pH allowing it to easily immobilize by multipoint covalent attachments on highly activated glyoxyl agarose gels. Initial immobilization resulted only in slight stabilization in relation to the free enzyme, since involvement of all subunits was not achieved. Coating the catalyst with aldehyde-dextran or polyethylenimine, fully stabilized the quaternary structure of the enzyme rendering much more stabilization to the biocatalyst. The catalyst coated with polyethylenimine of molecular weight 1300 is the most stable one exhibiting an interesting half-life of more than 10 days at pH 5.0 and 50 degrees C, being, therefore, 240-fold more stable than free enzyme. Optimum activity was observed in the pH range 4.0-6.0 and at 55 degrees C. The catalyst retained its side activity against p-nitrophenyl -l-arabinofuranoside and it was inhibited by xylose and glucose. Kinetic parameters with p-nitrophenyl -d-xylopyranoside as substrate were V-max 0.20mol.min(-1)mgprot.(-1), K-m 0.45mM, K-cat 0.82s(-1), and K-cat/K-m 1.82s(-1)mM(-1). Xylose release was observed from the hydrolysis of xylooligosaccharides with a decrease in the rate of xylose release by increasing substrate chain-length. Due to the high thermostability and the complete stability after five reuse cycles, the applicability of this biocatalyst in biotechnological processes, such as for the degradation of lignocellulosic biomass, is highly increased.

  DOI：

  10.1080/10242422.2016.1247817

文献信息

• Structure of an l-arabino-d-xylan from the bark of Cinnamomum zeylanicum
  作者：D. Channe Gowda、Chitra Sarathy

  DOI：10.1016/0008-6215(87)80062-9

  日期：1987.9

  d -xylose in the molar ratio 1.6:1.0. Partial hydrolysis furnished oligosaccharides which were characterised as α- d -Xyl p -(1→3)- d -Ara, β- d Xyl p -(1→4)- d -Xyl, β- d -Xyl p -(1→4)-β- d -Xyl p -(1→4)- d -Xyl, β- d -Xyl p -(1→4)-β- d -Xyl p -(1→4)-β- d -Xyl p -Xyl p -(1→4)- d -Xyl, xylopentaose, and xylohexaose. Mild acid hydrolysis of the arabinoxylan gave a degraded polysaccharide consisting of

  摘要从桂皮中提取的阿拉伯木聚糖由1-阿拉伯糖和d-木糖组成，摩尔比为1.6：1.0。部分水解得到的寡糖的特征是α-d -Xyl p-（1→3）-d -Ara，β-d Xyl p-（1→4）-d -Xyl，β-d -Xyl p-（1 →4）-β-d -Xyl p-（1→4）-d -Xyl，β-d -Xyl p-（1→4）-β-d -Xyl p-（1→4）-β-d -Xyl p -Xyl p-（1→4）-d -Xyl，木基戊糖和木六糖。阿拉伯糖基木聚糖的轻度酸水解产生了由1-阿拉伯糖（8％）和d-木糖酶（92％）组成的降解的多糖。甲基化分析表明降解的多糖为线性（1→4）连接的d -xlan，其中一些吡喃吡喃糖基残基在O-2或O-3处被1-阿拉伯呋喃糖基取代。
• OLIGOSACCHARIDES OF XYLOSE FROM WHEAT STRAW HEMICELLULOSE
  作者：C. T. Bishop

  DOI：10.1139/v55-124

  日期：1955.6.1

  A series of oligosaccharides were prepared by autoclaving wheat straw hemicellulose at 120 °C. in distilled water. The di- to the hepta-saccharide inclusive were shown to be members of the (1 → 4)-β-D-xylopyranose series. The octasaccharide was shown to be doubly branched. Certain aspects of the structure of wheat straw hemicellulose are discussed on the basis of these results.

  一系列寡糖在120℃的蒸汽压力锅中，使用蒸馏水从小麦秸秆半纤维素中制备而成。其中二糖到七糖都属于(1→4)-β-D-木聚糖系列。八糖则被证明是双分支的。基于这些结果，讨论了小麦秸秆半纤维素的某些结构方面。
• Characterization of a recombinant multifunctional glycoside hydrolase family 3 β-xylosidase/α-l-arabinofuranosidase/β-glucosidase from Cellulosimicrobium cellulans sp. 21
  作者：Ye Yuan、Yanbo Hu、Han Zhang、Jiayi Leng、Fan Li、Xuesong Zhao、Juan Gao、Yifa Zhou

  DOI：10.1016/j.molcatb.2016.06.002

  日期：2016.9

  A multifunctional beta-xylosidase/alpha-L-arabinofuranosidase/beta-glucosidase gene (ccxyl3a) belonging to glycoside hydrolase family 3 (GH3) was cloned from Cellulosimicrobium cellulans sp. 21 and expressed in Escherichia coli BL21 (DE3). The molecular mass of recombinant CcXyl3A was estimated to be approximately 95 kDa. With p-nitrophenyl-beta-D-xyloside (pNP beta Xyl) as a substrate, the purified protein, presented an optimal pH of 8.5 and an optimal temperature of 45 degrees C. Moreover, CcXyl3A was activated in the presence of the metals K+ and Na+. Purified CcXyl3A demonstrated multifunctional activities on pNP beta Xyl, p-nitrophenyl-beta-D-glucoside (pNP beta G1c), and p-nitrophenyl-alpha-L-arabinofuranoside (pNP alpha Araf). The greatest catalytic activity were found on pNP beta Xyl followed by pNPaAraf and pNP beta G1c, respectively. Using xylooligosaccharides as substrate, CcXyl3A completely hydrolyzed xylobiose, xylotriose, xylotetraose and xylohexaose, xylose was the sole product. In addition, CcXyl3A synergistically acted with Thermomyces lanuginosus xylanase in the degradation of beechwood xylan, released xyloses from intermediate xylooligosaccharides produced by T. lanuginosus xylanase. To date, this is the first report to demonstrate the cloning and characterization of a multifunctional GH3 enzyme in C. cellulans that may have applications in hemicellulose degradation. (C) 2016 Elsevier B.V. All rights reserved.
• Characterization of a thermostable, specific GH10 xylanase from Caldicellulosiruptor bescii with high catalytic activity
  作者：Jiao An、Yuan Xie、Yong Zhang、Dongsheng Tian、Shuhao Wang、Guangyu Yang、Yan Feng

  DOI：10.1016/j.molcatb.2015.04.003

  日期：2015.7

  Xylanase (EC 3.2.1.8) is one of the most important enzymes for the biodegradation of xylan. Since many industrial processes utilizing xylanase are operated at elevated temperatures, thermostable xylanases are highly desirable. In the present study, xyn10B gene from thermophilic bacterium Caldicellulosiruptor bescii that encodes a glycoside hydrolase (GH) family 10 xylanase was overexpressed in Escherichia coli and systematically characterized. CbXyn10B exhibited optimal activity at pH 7.2 and 70 degrees C. It had a half-life of about 7.7h at 60 degrees C, and retained over 85% of maximal activity after incubation at pH 4.0-12.0. The activity of this xylanase was not affected by most divalent cations, but inhibited by Fe3+ and Zn2+. CbXyn10B exhibited high activity on beech wood xylan, oat spelt xylan, and birch wood xylan, with specific activities of about 450 U mg(-1). Compared with other GH10 xylanases, CbXyn10B was highly specific for xylan and showed low catalytic efficiency toward sodium carboxymethyl cellulose and p-nitrophenyl-beta-D-xylopyranoside. HPLC analysis of the products released from xylo-oligosaccharides and xylan revealed that xylobiose was the predominant hydrolytic product. The action mode of the enzyme was studied by product analysis, homology modeling and molecular docking to gain an insight into the structural basis for its substrate recognition mechanism. (C) 2015 Elsevier B.V. All rights reserved.
• The impact of dilute sulfuric acid on the selectivity of xylooligomer depolymerization to monomers
  作者：Rajeev Kumar、Charles E. Wyman

  DOI：10.1016/j.carres.2007.10.022

  日期：2008.2

  The disappearance of xylose and xylooligosaccharides with degrees of polymerization (DP) ranging from 2 to 5 was followed at 160 C with sulfuric acid added to adjust the pH from near neutral to 1.45, and the impact on the yields of lower DP xylooligomers and xylose monomer was determined. In addition, the experimental data for the disappearance of these xylooligomers was kinetically modeled assuming first-order reaction kinetics for xylose degradation and xylooligomer hydrolysis to evaluate how the pH affected the selectivity of monomer formation from xylooligomers and direct oligomer degradation to unknown products. The yield of xylose from xylooligomers increased appreciably with increasing acid concentration but decreased with increasing xylooligomer DP at a given acid concentration, resulting in more acid being required to realize the same xylose yields for higher DP species. For example, the maximum xylose yields were 49.6%, 28.0%, 13.2% and 3.2% for DP values of 2, 3, 4, and 5, respectively, at pH 4.75. Kinetic modeling revealed that all the xylooligomers disappeared at a higher rate compared to xylose monomer and the disappearance rate constant increased with DP at all pH. The kinetics for lower DP oligomers of 2 and 3 showed that these species directly degrade to unknown compounds in the absence of acid. On the other hand, higher oligomers of DP 4 and 5 exhibited negligible losses to degradation products at all pH. Therefore, only xylooligomers of DP 2 and 3 were found to directly degrade to undesired products in the absence of acid, but more work is needed to determine how higher DP species behave. This study also revealed that the source of water and the material used for the construction of the reactor impacted xylose degradation kinetics. (c) 2007 Elsevier Ltd. All rights reserved.

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