A glucan is any of a class of
complex sugars (
polysaccharides) that serve a variety of functions in living
cells. For instance, 1,3-Β-D-glucan gives the necessary stiffness to the
cell walls of
microbes such as
algae,
bacteria and
fungi. Some
vitamin and
herb manufacturers are also touting 1,3-Β-D-glucan as a
supplement to boost one's
immune system, but this use has not been validated in
clinical trials.
Glucans are composed of D-glucose monomers linked together by glycosidic bonds. Dextran, laminarin, and lichenin are other examples of glucans.