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Polysaccharides & oligosaccharides have a wide range of functions in both industry & the natural world. Saccharides have the potential to adopt an incredible number of conformations. The role of saccharides in cellular communication/recognition is beginning to be elucidated within the scientific comriiunity. The immune system especially uses saccharides to recognise 'self & 'non-self. The potential influence of saccharides upon the functioning of the immune system is enormous. The analysis of polysaccharides & oligosaccharide samples using an immune based method could provide an insight into the relationship between saccharide structure-function. Reactive oxygen species (ROS) were used.to monitor immune cell activity & therefore asses the immunomodulatory effect ofpolysaccharides & oligosaccharides. A fluorescent method was developed that provides a dynamic, reliable, efficient, non-operator assessed technique for the analysis of ROS. The technique uses the compound 2' 7'-dichlorofluorescein diacetate (DCFH-DA). DCFH-DA is a non-fluorescent compound that can pass through cell membranes. Once it is in the cytoplasm, esterases remove the acetates to produce 2', 7'-dichlorodihydrofluorescein (DCFH). DCFH is easily oxidised to 2', 7'-dichlorofluorescein (DCF) a highly fluorescent compound (excitation 485 nm; emission 530 nm). The polysaccharides gellan gum caused increase of up to 80% in ROS production compared to control immune cells. Tremellan also caused increases of up to 74% in ROS production by immune cells. Several yeast cell wall fractions were tested, all of which showed immunostimulatory effects on the production of ROS. An L-fucose-rich c1avan caused 22% inhibition of ROS production, whilst locust bean gum caused up to 48% inhibition ofROS production by immune cells. Monosaccharides & oligosaccharides with degrees of polymerisation (DP) ranging from 1 to 8 were also tested for their immunomodulatory properties on the production of ROS. Laminarihexaose (DP 6) and laminariheptaose (DP 7) gave differing results because of their DP &Jor structure, with laminarihexaose causing a 16% decrease in ROS production and laminariheptaose causing a 25% increase in ROS production from immune cells compared to control cells after 60 minutes. A series of arabino-oligosaccharide (DP 6, 7 & 8) were also tested. As their DP increased so did their inhibitory effect on ROS production by immune cells. Manno-oligosaccharides (DP 5-7), derived from locust bean gum, gave similar results to its parent polysaccharide. Many other poly~ccharides & oligosaccharides were tested, giving stimulatory, inhibitory and neutral results. These results have provided an insight into the relationship between size/structure-function of saccharides. The potential for further tests and manufacture ofdesigner oligosaccharides using these results is vast.

The Fmoc synthetic strategy was employed to synthesise two identical combinatorial peptide libraries on a hydrophilic PEG-PS resin. One library was appended with boronic acid moieties at two positionally-fixed locations. Successful inclusion of the boronic acid units was confirmed using a novel UV fluorescent colorimetric assay employing carminic acid as the dye compound. A study of the effect had by the resin-bound peptides bearing boronic acid groups on the binding characteristics of vancomycin, a medically relevant antibiotic glycoprotein, was conducted. In all, 132 library compounds were tested for their binding affinity with vancomycin, via immobilisation of the glycopeptide onto the solid support through hydrogen bonding or complexation with the boronic acid moieties. Subsequent cleavage via acidolysis afforded vancomycin containing solutions which were quantified by growth inhibition of methicillin susceptible Staphylococcus aureus. Comparison of the diameters of the resultant zones of inhibition and those produced by vancomycin of known concentrations afforded a means of calculating the vancomycin concentration of the cleavage solutions, and thereby determining the binding affinity of vancomycin to each peptide sequence. Five peptide sequences and twenty one of the peptidyl-boronic acid sequences showed zones of inhibition, demonstrating their reversible affinity for vancomycin. Three peptide sequences showed zones of inhibition in both libraries. The presence of boronic acid was therefore shown to impart, enhance, detract and remove the affinity of vancomycin to a range of resin-bound peptide sequences.