N,N',N'',N'''-tetraacetylchitotetraose

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: N,N',N'',N'''-tetraacetylchitotetraose
• 英文别名: chitotetraose；GlcNAcβ(1,4)GlcNAcβ(1,4)GlcNAcβ(1,4)GlcNAc；Tetraacetyl-Chitotetraose；N-[(3R,4R,5S,6R)-5-[(2S,3R,4R,5S,6R)-3-acetamido-5-[(2S,3R,4R,5S,6R)-3-acetamido-5-[(2S,3R,4R,5S,6R)-3-acetamido-4,5-dihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy-4-hydroxy-6-(hydroxymethyl)oxan-2-yl]oxy-4-hydroxy-6-(hydroxymethyl)oxan-2-yl]oxy-2,4-dihydroxy-6-(hydroxymethyl)oxan-3-yl]acetamide
• 化学式: C₃₂H₅₄N₄O₂₁
• 分子量: 830.795
• InChiKey: PFZKWTWCVGDJQC-VNVOTFTJSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  -9
• 重原子数：
  57
• 可旋转键数：
  14
• 环数：
  4.0
• sp3杂化的碳原子比例：
  0.88
• 拓扑面积：
  383
• 氢给体数：
  14
• 氢受体数：
  21

反应信息

• 作为反应物：
  描述：

  N,N',N'',N'''-tetraacetylchitotetraose 在 phosphate buffer 作用下， 反应 106.0h， 生成 D-GlcNAc
  参考文献：
  名称：

  糖苷酶催化的寡糖合成：米曲霉的β - N-乙酰基己糖胺酶制备N-乙酰基壳寡糖，spenta- N-乙酰基壳五糖和六-N-乙酰基己糖

  摘要：

  使用来自米曲霉的粗β - N-乙酰基己糖胺酶，三-N-乙酰基壳三糖（GlcNAc）3（1，n = 1）和四-N-乙酰基壳四糖（GlcNAc）4（1，n = 2）分别充当两个糖基供体和糖基受体，得到含有大量相应的五糖和六糖[分别为1（n = 3）和1（n = 4）]的产物混合物，可以通过木炭-Celite色谱法轻松分离和纯化该混合物。

  DOI：

  10.1016/0957-4166(95)00370-5
• 作为产物：
  描述：

  在 palladium on activated charcoal sodium methylate 、 氢气 作用下， 以 甲醇 、 1,4-二氧六环 、 溶剂黄146 为溶剂， 反应 72.0h， 以100%的产率得到N,N',N'',N'''-tetraacetylchitotetraose
  参考文献：
  名称：

  Synthesis of chitotetraose and chitohexaose based on dimethylmaleoyl protection

  摘要：

  tert-Butyldimethylsilyl 3,6-di-O-benzyl-2-deoxy-2-dimethylmaleimido-beta -D-glucopyranoside was readily transformed into the disaccharide glycosyl donor, 3,4,6-tri-O-acetyl-2-deoxy-2-dimethylmaleimido-beta -D-glucopyranosyl-(1 --> 4)-3,6-di-O-benzyl-2-deoxy-2-dimethylmaleimido-alpha/beta -D-glucopyranosyl trichloroacetimidate, and the disaccharide glycosyl acceptor, tert-butyldimethylsilyl 3,6-di-O-benzyl-2-deoxy-2-dimethylmaleimido-beta -D-glucopyranosyl-(1 --> 4)-3,6-di-O-benzyl-2-deoxy-2-dimethylmaleimido-beta -D-glucopyranoside. A TMSOTf-catalysed coupling of the acceptor with the donor afforded the respective tetrasaccharide derivative, which can be transformed to chitotetraose. tert-Butyldimethylsilyl 3,6-di-O-benzyl-2-deoxy-2-dimethylmaleimido-4-O-phenoxyacetyl-beta -D-glucopyranosyl-(1 --> 4)-3,6-di-O-benzyl-2-deoxy-2-dimethylmaleimido-beta -D-glucopyranoside was converted into donor 3,6-di-O-benzyl-2-deoxy-2-dimethylmaleimido-4-O-phenoxyacetyl-beta -D-glucopyranosyl- (1 --> 4)-3,6-di-O-benzyl-2-deoxy-2-dimethylmaleimido-beta -D-glucopyranosyl trichloroacetimidate. Its coupling with benzyl 3,6-di-O-benzyl-2-deoxy-2-dimethylmaleimido- beta -D-glucopyranosyl-(1 --> 4)-3,6-di-O-benzyl-2-deoxy-2-dimethylmaleimido-beta -D-glucopyranoside, followed by dephenoxyacetylation, gave benzyl 3,6-di-O-benzyl-2-deoxy-2-dimethylmaleimiido-beta -D-glucopyranosyl- (1 --> 4)-3,6-di-O-benzyl-2-deoxy-2-dimethyimaleimido-beta -D-glucopyranosyl-(1 --> 4)- 3,6-di-O-benzyl-2-deoxy-2-dimethylmaleimido- beta -D-glucopyranosyl-(1 --> 4)-3.6-di-O-benzyl-2-deoxy-2-dimethylmaleimido-beta -D-glucopyranoside, whose glycosylation furnished, after replacement of the DMM-group by the acetyl moiety and subsequent deprotection, chitohexaose. (C) 2001 Elsevier Science Ltd. All rights reserved.

  DOI：

  10.1016/s0008-6215(01)00024-6

文献信息

• Direct Dehydrative Pyridylthio-Glycosidation of Unprotected Sugars in Aqueous Media Using 2-Chloro-1,3-dimethylimidazolinium Chloride as a Condensing Agent
  作者：Naoki Yoshida、Masato Noguchi、Tomonari Tanaka、Takeshi Matsumoto、Naoya Aida、Masaki Ishihara、Atsushi Kobayashi、Shin-ichiro Shoda

  DOI：10.1002/asia.201000896

  日期：2011.7.4

  enzyme inhibitors in sugar chemistry, have been synthesized directly from the corresponding unprotected sugars in good yields by using 2‐chloro‐1,3‐dimethylimidazolinium chloride (DMC) as dehydrative condensing agent. The reaction proceeds in aqueous media without using any protecting groups, affording 2‐pyridyl 1‐thioglycosides with β‐configuration selectively. According to the present method, not

  通过使用2-氯-1,3-二甲基咪唑啉鎓氯化物（DMC）作为脱水缩合剂，可以直接从相应的未保护糖以高收率直接合成各种2-吡啶基1-硫代糖苷，糖化学中的重要合成中间体和酶抑制剂。反应在水性介质中进行，无需使用任何保护基，选择性地提供具有β-构型的2-吡啶基1-硫代糖苷。根据本方法，不仅未保护的单糖，而且未保护的寡糖，例如纤维寡糖，壳寡糖，麦芽寡糖和氨基葡萄糖低聚物，都可以转化为相应的2-吡啶硫基衍生物，这将大大扩展芳基1-硫代糖苷在糖化学中的应用。
• 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。
• A glycosynthase derived from an inverting GH19 chitinase from the moss <i>Bryum coronatum</i>
  作者：Takayuki Ohnuma、Tatsuya Fukuda、Satoshi Dozen、Yuji Honda、Motomitsu Kitaoka、Tamo Fukamizo

  DOI：10.1042/bj20120036

  日期：2012.6.15

  BcChi-A, a GH19 chitinase from the moss Bryum coronatum, is an endo-acting enzyme that hydrolyses the glycosidic bonds of chitin, (GlcNAc)n [a β-1,4-linked polysaccharide of GlcNAc (N-acetylglucosamine) with a polymerization degree of n], through an inverting mechanism. When the wild-type enzyme was incubated with α-(GlcNAc)2-F [α-(GlcNAc)2 fluoride] in the absence or presence of (GlcNAc)2, (GlcNAc)2 and hydrogen fluoride were found to be produced through the Hehre resynthesis–hydrolysis mechanism. To convert BcChi-A into a glycosynthase, we employed the strategy reported by Honda et al. [(2006) J. Biol. Chem. 281, 1426–1431; (2008) Glycobiology 18, 325–330] of mutating Ser102, which holds a nucleophilic water molecule, and Glu70, which acts as a catalytic base, producing S102A, S102C, S102D, S102G, S102H, S102T, E70G and E70Q. In all of the mutated enzymes, except S102T, hydrolytic activity towards (GlcNAc)6 was not detected under the conditions we used. Among the inactive BcChi-A mutants, S102A, S102C, S102G and E70G were found to successfully synthesize (GlcNAc)4 as a major product from α-(GlcNAc)2-F in the presence of (GlcNAc)2. The S102A mutant showed the greatest glycosynthase activity owing to its enhanced F− releasing activity and its suppressed hydrolytic activity. This is the first report on a glycosynthase that employs amino sugar fluoride as a donor substrate.

  BcChi-A 是一种来自藓苔 Bryum coronatum 的 GH19 几丁质酶，它是一种内作用酶，可通过倒置机制水解几丁质的糖苷键 (GlcNAc)n[聚合度为 n 的 GlcNAc（N-乙酰葡糖胺）β-1,4 链式多糖]。在没有(GlcNAc)2或有(GlcNAc)2存在的情况下，野生型酶与α-(GlcNAc)2-F [α-(GlcNAc)2氟化物]孵育时，发现(GlcNAc)2和氟化氢是通过Hehre再合成-水解机制产生的。为了将 BcChi-A 转化为糖合成酶，我们采用了 Honda 等人报告的策略[（2006）J. Biol. Chem. 281, 1426-1431; （2008）Glycobiology 18, 325-330]，即突变具有亲核水分子的 Ser102 和作为催化碱基的 Glu70，产生 S102A、S102C、S102D、S102G、S102H、S102T、E70G 和 E70Q。在我们使用的条件下，除 S102T 外，所有突变酶都检测不到对 (GlcNAc)6 的水解活性。在无活性的 BcChi-A 突变体中，发现 S102A、S102C、S102G 和 E70G 能在 (GlcNAc)2 存在的情况下成功合成 (GlcNAc)4 作为来自 α-(GlcNAc)2-F的主要产物。S102A 突变体的糖合成酶活性最强，因为它的 F 释放活性增强，水解活性被抑制。这是首次报道使用氨基糖氟化物作为供体底物的糖合成酶。
• The Amino Acid Sequence of Satyr Tragopan Lysozyme and Its Activity
  作者：Tomohiro ARAKI、Gen TOSHIMA、Tomomi KUSAO、Yuki CHIJIIWA、Shunsuke KAWAMURA、Takao TORIKATA

  DOI：10.1271/bbb.67.2621

  日期：2003.1

  The amino acid sequence of satyr tragopan lysozyme and its activity was analyzed. Carboxymethylated lysozyme was digested with trypsin and the resulting peptides were sequenced. The established amino acid sequence had three amino acid substitutions at positions 103 (Asn to Ser), 106 (Ser to Asn), and 121 (His to Gln) comparing with Temminck's tragopan lysozyme and five amino acid substitutions at positions 3 (Phe to Tyr), 15 (His to Leu), 41 (Gln to His), 101 (Asp to Gly) and 103 (Asn to Ser) with chicken lysozyme. The time course analysis using N-acetylglucosamine pentamer as a substrate showed a decrease of binding free energy change, 1.1 kcal/mol at subsite A and 0.2 kcal/mol at subsite B, between satyr tragopan and chicken lysozymes. This was assumed to be responsible for the amino acid substitutions at subsite A-B at position 101 (Asp to Gly), however another substitution at position 103 (Asn to Ser) considered not to affect the change of the substrate binding affinity by the observation of identical time course of satyr tragopan lysozyme with turkey and Temminck's tragopan lysozymes that carried the identical amino acids with chicken lysozyme at this position. These results indicate that the observed decrease of binding free energy change at subsites A-B of satyr tragopan lysozyme was responsible for the amino acid substitution at position 101 (Asp to Gly).

  分析了撒图尔真鸡（satyr tragopan）溶菌酶的氨基酸序列及其活性。对羧甲基化的溶菌酶进行胰酶消化，得到的肽段被测序。与坦明克的真鸡（Temminck's tragopan）溶菌酶相比，确立的氨基酸序列在第103位（Asn变为Ser）、第106位（Ser变为Asn）和第121位（His变为Gln）有三个氨基酸替换；与鸡溶菌酶相比，第3位（Phe变为Tyr）、第15位（His变为Leu）、第41位（Gln变为His）、第101位（Asp变为Gly）和第103位（Asn变为Ser）有五个氨基酸替换。使用N-乙酰氨基葡萄糖五聚体作为底物的时间过程分析显示，撒图尔真鸡与鸡溶菌酶在A位点的结合自由能变化减少了1.1 kcal/mol，在B位点减少了0.2 kcal/mol。这被认为与第101位（Asp变为Gly）处的氨基酸替换有关，而第103位（Asn变为Ser）处的另一替换则被认为不会影响底物结合亲和力的变化，因为观察到撒图尔真鸡溶菌酶与火鸡及坦明克真鸡溶菌酶的时间过程相同，这些溶菌酶在该位置上与鸡溶菌酶具有相同的氨基酸。这些结果表明，撒图尔真鸡溶菌酶在A-B位点观察到的结合自由能变化的减少是由第101位（Asp变为Gly）处的氨基酸替换引起的。
• 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。