7284-18-6Relevant articles and documents
A new synthesis of 2-acetamido-4-O-2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-β-D-glucopyranosyl) -1,3,6-tri-O-acetyl-2-deoxy-α-D-glucopyranose (Chitobiose octaacetate)
Oguri,Tejima
, p. 3184 - 3811 (1980)
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Acetylated chitosan oligosaccharides act as antagonists against glutamate-induced PC12 cell death via Bcl-2/Bax signal pathway
Hao, Cui,Gao, Lixia,Zhang, Yiran,Wang, Wei,Yu, Guangli,Guan, Huashi,Zhang, Lijuan,Li, Chunxia
, p. 1267 - 1289 (2015/04/14)
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.
Probing the mechanism of a fungal glycosyltransferase essential for cell wall biosynthesis. UDP-Chitobiose is not a substrate for chitin synthase
Chang, Robert,Yeager, Adam R.,Finney, Nathaniel S.
, p. 39 - 41 (2007/10/03)
Chitin synthase is responsible for the biosynthesis of chitin, an essential component of the fungal cell wall. There is a long-standing question as to whether "processive" transferases such as chitin synthase operate in the same manner as non-processive transferases. The question arises from analysis of the polysaccharide structure - in chitin, for instance, each sugar residue is rotated ca. 180 deg relative to the preceding sugar in the chain. This requires that the enzyme account for the alternating "up/down" configuration during biosynthesis. An enzyme with a single active site, analogous to the non-processive transferases - would have to accommodate a distorted glycosidic linkage at every other synthetic step. An alternative proposal is that the enzyme might assemble the disaccharide donor, addressing the "up/down" conformational problem prior to polymer synthesis. We present compelling evidence that this latter hypothesis is incorrect.