2D Selective-TOCSY–DQFCOSY and HSQC–TOCSY NMR experiments for assignment of a homogeneous asparagine-linked triantennary complex type undecasaccharide

详细信息	查看全文 | 推荐本文 |

• 作者：Hajime Sato ; Kazuhiro Fukae ; Yasuhiro Kajihara
• 关键词：Triantennary undecasaccharide ; 2D Selective-TOCSY&#x2013 ; DQFCOSY ; HSQC&#x2013 ; TOCSY ; Complete assignment ; Glycosyl position
• 刊名：Carbohydrate Research
• 出版年：2008
• 期刊代码：15_00086215
• 类别：ch
• 出版时间：9 June 2008
• 卷：343
• 期：8
• 页码：1333-1345
• 文件大小：1579 K

摘要

The assignment of ¹H and ¹³C NMR signals of a complex type triantennary asialooligosaccharide was examined using 2D selective-TOCSY–DQFCOSY and HSQC–TOCSY experiments. The 2D selective-TOCSY–DQFCOSY experiment exhibits a 2D DQFCOSY spectrum of an individual monosaccharide in the undecasaccharide, although the NMR signals of several monosaccharides in the triantennary undecasaccharide are heavily overlapped. Selective excitation of each anomeric proton signal and subsequent TOCSY experiment afforded transverse magnetization corresponding to all of the proton signals of the monosaccharide. This magnetization was then developed with the corresponding DQFCOSY pulse sequence to afford the DQFCOSY spectrum of the individual monosugars. In this case, four GlcNAc-b, -e, -j, and -h residues were excited as a mixture. In order to assign ¹³C signals, a conventional 2D HSQC–TOCSY spectrum was examined and compared with an unambiguous assignment of 2D selective-TOCSY–DQFCOSY thus obtained. This systematic analysis made it possible to obtain an assignment of the ¹H and ¹³C NMR signals of the triantennary undecasaccharide. In addition, these experiments also revealed all of the glycosyl positions in the triantennary undecasaccharide.