Immunostimulant oxidized β-glucan conjugates

β-Glucans are polysaccharides that act as nonspecific immune system stimulants. However, many β-Glucans are sparingly soluble in water. This work describes an oxidative procedure, which solubilizes the β-Glucan from Saccharomyces cerevisiae and maintains its immunostimulatory properties. Furthermore, the carboxylates at the site of oxidation allow for the conjugation of small molecule immunostimulants. Both the parent oxidized β-glucan and its conjugates with O-β-alanyl-5-[6-( N, N′-dimethylamino)purin-9-yl]pentanol stimulate cytotoxic T-lymphocytes (CTLs), B cells and macrophages. In addition, they both stimulate natural killer (NK) cells, a property which the small molecule purine does not possess.