Automated Structure Characterisation of Oligosaccharide Mixtures by NMR (ASCOM-NMR)

Lead Research Organisation: University of Edinburgh
Department Name: Sch of Chemistry

Abstract

Oligosaccharides are the subject of growing commercial interest for a wide range of applications in healthcare and personal care. They are commonly prepared by depolymerisation of polysaccharides which are important industrial biotechnology products from biomass (animal tissue, plant biomass and macroalgae), microalgae and bacterial fermentation. The characterization of oligosaccharide mixtures produced by the depolymerisation is one of the bottlenecks in the discovery and subsequent development of scalable downstream processing of active oligosaccharides. This project aims to develop automated NMR based characterisation of oligosaccharide mixtures without the need for their physical separation.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/N509644/1 01/10/2016 30/09/2021
1799719 Studentship EP/N509644/1 01/09/2016 28/02/2020 Elaine Katrina Adair
 
Description -How to program software for the semi-automated assignment of NMR spectra for simple carbohydrates (i.e. up to pentasaccharides). However, using the same program for complex samples (i.e. polysaccharides, complex mixtures), is not yet possible due to the complexity of the spectra.
-A new NMR experiment (SHARPER-J) which allows for greater accuracy when measuring J-couplings (i.e. the strength of the indirect interaction through bonds between nuclei); performing the same experiment on a sample in an alignment medium also allows for the accurate determination of residual dipolar couplings in solution (which normally can only be achieved using solid state NMR), and hence bond angles between nuclei can be determined.
-The biosynthesis pathway of the cell wall of Streptococcus was studied and it was discovered that in the first step of the synthesis was actually different from the accepted literature.
-A pure-shift TOCSY experiment which up-scales the chemical shift and increases the resolution was developed.
Exploitation Route -My thesis will explore the difficulties in developing a program which fully automates the assignment of complex carbohydrate NMR spectra, and why programs which work on simpler carbohydrates will not suffice for complex mixtures of carbohydrates. Moreover, it will also explore NMR experiments used to aid automated assignment, and their pros/cons. This will help anybody in the future who wishes to attempt developing a similar program.
-The SHARPER-J experiment may prove useful to researchers who wish to measure the J-coupling of nuclei whose 1D spectral peaks are overlapped; moreover, SHARPER-J will also give researchers the opportunity to determine the stereo-chemistry of solution state samples.
-By understanding how Streptococcus is synthesised, new drugs can be developed to tackle the diseases that it causes.
-The new TOCSY experiment will allow for overlapped and broad signals to be separated and seen more easily, hence it can help to solve extremely complex samples.
Sectors Agriculture, Food and Drink,Chemicals,Healthcare,Pharmaceuticals and Medical Biotechnology