Glucan

A glucan is a polysaccharide derived from D-glucose, linked by glycosidic bonds. Glucans are noted in two forms: alpha glucans and beta glucans. Many beta-glucans are medically important. They represent a drug target for antifungal medications of the echinocandin class. In the field of bacteriology, the term polyglucan is used to describe high molecular mass glucans. They are structural polysaccharide consisting of a long linear chain of several hundred to many thousands D-glucose monomers. The point of attachment is O-glycosidic bonds, where a glycosidic oxygen links the glycoside to the reducing end sugar. Polyglucans naturally occur in the cell walls of bacteria. Bacteria produce this polysaccharide in a cluster near the bacteria's cells. Polyglucan's are a source of beta-glucans. Structurally, beta 1.3-glucans are complex glucose homopolymers binding together in a beta-1,3 configuration.