Implemented Analytical Methods for Qualitative Analysis of Carbohydrates

• Main Authors: Johansson, Emil, Wallgren, Jakob
• Format: Others
• Language: English
• Published: Linköpings universitet, Institutionen för fysik, kemi och biologi 2012
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-85276

Structural analysis of carbohydrates can be of great importance when studying the effects of bacteria such as Gram negative Haemophilus Influenzae. In the case of Gram negative Haemophilus Influenzae type B the knowledge of the structure have been used to develop a vaccine for meningitis. The aim of the thesis is to implement known analytical methods of determining the structure of saccharides of varying sizes at IFM, Linköping University. An emphasis has been put on GC-MS on methylated and acetylated saccharides, although NMR and MALDI has also been used. The structural analysis of this thesis encompasses elements such as anomeric configuration, sequence, the identification of monosaccharides which are building block of larger oligo- or polysaccharides and linkage locations between these monosaccharides. To do this a model substance was used, the choice was lactose as it is a simple carbohydrate and therefore easy to work with. Once the model substance had been tried and tested other carbohydrates were analyzed such as streptococcus pneumonia and cholera. The methods of methylation using two different recipes as well as acetylation to identify monosaccharides were successfully implemented at IFM using the model substance, lactose. Due to solubility issues the same methods were not found to be applicable at IFM on the polysaccharides streptococcus pneumonia and cholera given the time frame of this thesis. MALDI was tried as a substitute for LC-ESI-MS and was somewhat successful at replicating an analysis of a carbohydrate. MALDI was also successfully used as a way of confirming that chemical reactions such as methylation and acetylation had indeed occurred. The analysis of lactose using NMR in both one dimension and two dimensions allowed for the determination of the anomeric configuration as well as an attempt of listing the chemical shifts of the ring protons. This thesis has generally been successful of implementing said analytical methods of structural analysis of carbohydrates although a lot of improvements can still be made, especially when it comes to optimization of these methods.