chitosan tetramer

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: chitosan tetramer
• 英文别名: chitotetraose；GlcN(b1-4)GlcN(b1-4)GlcN(b1-4)GlcN；(2R,3S,4R,5R,6S)-5-amino-6-[(2R,3S,4R,5R,6S)-5-amino-6-[(2R,3S,4R,5R,6S)-5-amino-6-[(2R,3S,4R,5R)-5-amino-4,6-dihydroxy-2-(hydroxymethyl)oxan-3-yl]oxy-4-hydroxy-2-(hydroxymethyl)oxan-3-yl]oxy-4-hydroxy-2-(hydroxymethyl)oxan-3-yl]oxy-2-(hydroxymethyl)oxane-3,4-diol
• 化学式: C₂₄H₄₆N₄O₁₇
• 分子量: 662.646
• InChiKey: LXTRMZCYLAULGH-BWMMPDKDSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  -10.1
• 重原子数：
  45
• 可旋转键数：
  10
• 环数：
  4.0
• sp3杂化的碳原子比例：
  1.0
• 拓扑面积：
  371
• 氢给体数：
  14
• 氢受体数：
  21

反应信息

• 作为反应物：
  描述：

  chitosan tetramer 生成 (5Xi)-2-乙酰氨基-3,4,6-三-O-乙酰基-2-脱氧-beta-D-来苏-己糖吡喃糖苷-(1->4)-(5Xi)-2-乙酰氨基-3,6-二-O-乙酰基-2-脱氧-beta-D-来苏-己糖吡喃糖苷-(1->4)-(5Xi)-2-乙酰氨基-3,6-二-O-乙酰基-2-脱氧-beta-D-来苏-己糖吡喃糖苷-(1->4)-(5Xi)-2-乙酰氨基-1,3,6-三-O-乙酰基-2-脱氧-beta-D-来苏-吡喃己糖
  参考文献：
  名称：

  NAGJO, FUMIO;SAKAI, KAZUO;USUI, TAICHI;TAKAI, IZUMI;ISHIDO, YOSHIHARU, J. CARBOHYDR. CHEM., 7,(1988) N 1, 67-82

  摘要：

  DOI：
• 作为产物：
  描述：

  N,N',N'',N'''-tetraacetylchitotetraose 在 盐酸 、 sodium tetrahydroborate 、 chitin deacetylase 作用下， 生成 chitosan tetramer
  参考文献：
  名称：

  Deacetylation of chitin oligosaccharides of dp 2–4 by chitin deacetylase from Colletotrichum lindemuthianum

  摘要：

  Chitin oligosaccharides of degree of polymerization 2-4 were deacetylated by purified chitin deacetylase isolated from Colletotrichum lindemuthianum to give their corresponding breakdown products after purification by liquid chromatography. Data from FABMS analyses suggested that N, N', N '', N'''-tetraacetylchitotetraose and N, N', N ''-triacetylchitotriose were converted into fully-deacetylated corresponding chitosan oligomers. Conversely, N,N'-diacetylchitobiose [(GlcNAc)(2)] was deacetylated to give a product which showed an [M + H](+) pseudomolecular ion at m/z 383, suggesting that either of the two acetyl groups were removed. Further data from H-1 NMR analyses confirmed that the reaction product was 2-acetamido-4-O-(2-amino-2-deoxy-beta-D-glucopyranosyl)-2-deoxy-D-glucose [GlcN-GlcNAc]. The enzymatic method has three advantageous characteristics over chemical methods: (i) it does not cause unexpected degradation of the sugar chain, (ii) it is highly reproducible, and (iii) unique compounds such as GlcN-GlcNAc may be produced. (C) 1997 Elsevier Science Ltd.

  DOI：

  10.1016/s0008-6215(97)00166-3

文献信息

• Efficient chemoenzymatic synthesis of lipo-chitin oligosaccharides as plant growth promoters
  作者：R. Chambon、G. Despras、A. Brossay、B. Vauzeilles、D. Urban、J.-M. Beau、S. Armand、S. Cottaz、S. Fort

  DOI：10.1039/c5gc00623f

  日期：——

  This is an Accepted Manuscript, which has been through the RSC Publishing peer review process and has been accepted for publication. Accepted manuscripts are published online shortly after acceptance. This version of the article will be replaced by the fully edited, formatted and proof read Advance Article as soon as this is available.

  这是已接受的手稿，已通过RSC出版同行评审过程，并已被接受出版。接受的手稿在接受后不久就会在线发布。一旦可用，此版本的文章将被完全编辑，格式化并提供高级阅读的高级文章代替。
• Acetylated Chitosan Oligosaccharides Act as Antagonists against Glutamate-Induced PC12 Cell Death via Bcl-2/Bax Signal Pathway
  作者：Cui Hao、Lixia Gao、Yiran Zhang、Wei Wang、Guangli Yu、Huashi Guan、Lijuan Zhang、Chunxia Li

  DOI：10.3390/md13031267

  日期：——

  Chitosan oligosaccharides (COSs), depolymerized products of chitosan composed of β-(1→4) d-glucosamine units, have broad range of biological activities such as antitumour, antifungal, and antioxidant activities. In this study, peracetylated chitosan oligosaccharides (PACOs) and N-acetylated chitosan oligosaccharides (NACOs) were prepared from the COSs by chemcal modification. The structures of these monomers were identified using NMR and ESI-MS spectra. Their antagonist effects against glutamate-induced PC12 cell death were investigated. The results showed that pretreatment of PC12 cells with the PACOs markedly inhibited glutamate-induced cell death in a concentration-dependent manner. The PACOs were better glutamate antagonists compared to the COSs and the NACOs, suggesting the peracetylation is essential for the neuroprotective effects of chitosan oligosaccharides. In addition, the PACOs pretreatment significantly reduced lactate dehydrogenase release and reactive oxygen species production. It also attenuated the loss of mitochondrial membrane potential. Further studies indicated that the PACOs inhibited glutamate-induced cell death by preventing apoptosis through depressing the elevation of Bax/Bcl-2 ratio and caspase-3 activation. These results suggest that PACOs might be promising antagonists against glutamate-induced neural cell death.

  去乙酰基壳聚糖低聚糖（COSs）是由β-(1→4) d-氨基葡萄糖单元组成的壳聚糖的去聚合产物，具有广泛的生物活性，如抗肿瘤、抗真菌和抗氧化活性。在本研究中，通过化学修饰从COSs制备了全乙酰化壳聚糖低聚糖（PACOs）和N-乙酰化壳聚糖低聚糖（NACOs）。使用核磁共振（NMR）和电喷雾质谱（ESI-MS）鉴定了这些单体的结构。研究了它们对谷氨酸诱导的PC12细胞死亡的拮抗作用。结果表明，PACOs预处理PC12细胞显著抑制了谷氨酸诱导的细胞死亡，并且这种抑制作用呈浓度依赖性。与COSs和NACOs相比，PACOs表现出更好的谷氨酸拮抗作用，表明全乙酰化对壳聚糖低聚糖的神经保护作用至关重要。此外，PACOs预处理显著减少了乳酸脱氢酶的释放和活性氧的产生，并减轻了线粒体膜电位的丧失。进一步的研究表明，PACOs通过抑制Bax/Bcl-2比率升高和半胱天冬酶-3的激活来防止谷氨酸诱导的细胞凋亡。这些结果表明PACOs可能是对抗谷氨酸诱导神经细胞死亡的有前景的拮抗剂。
• Kinetics of hydrolysis of chitin/chitosan oligomers in concentrated hydrochloric acid
  作者：Aslak Einbu、Hans Grasdalen、Kjell M. Vårum

  DOI：10.1016/j.carres.2007.02.022

  日期：2007.6

  The kinetics of hydrolysis in concentrated hydrochloric acid (12.07 M) of the fully N-acetylated chitin tetramer (GlcNAc(4)) and the fully N-deacetylated chitosan tetramer (GlcN(4)) were followed by determining the amounts of the lower DP oligomers as a function of time. A theoretical model was developed to simulate the kinetics of hydrolysis of the three different glycosidic linkages in the tetramers

  完全N-乙酰化的几丁质四聚体（GlcNAc（4））和完全N-去乙酰化的壳聚糖四聚体（GlcN（4））在浓盐酸（12.07 M）中的水解动力学随后是确定低级DP的量低聚物是时间的函数。建立了理论模型以模拟四聚体中三种不同糖苷键的水解动力学。该模型使用两个不同的速率常数来水解低聚物中的糖苷键，前提是毗邻末端残基之一的糖苷键的水解速度快于其他两个糖苷键。通过将模型数据拟合到实验结果来估计两个速率常数。结果表明，四聚体的水解是一个非随机过程，因为与末端残基之一相邻的糖苷键的水解速度比完全N-乙酰化和完全N-去乙酰化的四聚体中的其他糖苷键快2.5和2.0倍， 分别。从其他低聚物的先前结果和反应机理来看，水解最快的糖苷键可能是紧靠非还原端的糖苷键。发现GlcNAc（4）中糖苷键的水解速率常数的绝对值比GlcN（4）中糖苷键的水解速率高50倍，这归因于N-乙酰基和N-去乙酰化糖残基上带正电荷的氨基的存在
• A convenient access to β-(1 → 4)-linked 2-amino-2-deoxy-d-glucopyranosyl fluoride oligosaccharides and β-(1 → 4)-linked 2-amino-2-deoxy-d-glucopyranosyl oligosaccharides by fluorolysis and fluorohydrolysis of chitosan
  作者：Jacques Defaye、Andrée Gadelle、Christian Pedersen

  DOI：10.1016/0008-6215(94)84023-7

  日期：1994.8

  sequence involving formation of the C-2 N-trifluoroacetate and subsequent simultaneous hydrolysis of the glycosyl fluoride and the amide substituent with aqueous methanol, yielded the free beta-(1-->4)-linked 2-amino-2-deoxy-D-glucopyranosyl oligosaccharides which were separated, for dp 2-11, by the same gel-exclusion technique. Both oligosaccharide series, either free or in the form of their alpha-glycopyranosyl

  通过在室温下将壳聚糖在无水氟化氢中进行氟解，可获得β-（1-> 4）-连接的2-氨基-2-脱氧-D-吡喃葡萄糖基寡糖，其还原端为α-吡喃葡萄糖基氟化物。温度。平均dp取决于反应时间，可通过13C NMR光谱方便地监控，使用大约98.5 ppm的β-（1-> 4）键合的C-1的信号比和末端糖基氟化物的C-1双峰部分约为104ppm。通过在Bio-Gel P-4上进行凝胶渗透色谱法，以乙酸-乙酸铵水溶液为洗脱液，在氟解18小时后获得dp 2-11糖基氟氟化低聚糖的制备级分。用高氯酸水溶液水解异头氟化物，或通过涉及形成C-2 N-三氟乙酸盐并随后用甲醇水溶液同时水解糖基氟和酰胺取代基的序列产生游离的β-（1→4）连接的2-氨基-2-通过相同的凝胶排阻技术将dp 2-11分离的脱氧-D-葡萄糖基吡喃糖基寡糖。两种寡糖系列，无论是游离的还是以其α-甘露糖基氟的形式，都得到了充分表征。
• DEFAYE, JACQUES;GADELLE, ANDREE;PEDERSEN, CHRISTIAN
  作者：DEFAYE, JACQUES、GADELLE, ANDREE、PEDERSEN, CHRISTIAN

  DOI：——

  日期：——