Glucan vs. Glycan — What's the Difference?

A glucan is a polysaccharide derived from D-glucose, linked by glycosidic bonds. Many beta-glucans are medically important.

The terms glycan and polysaccharide are defined by IUPAC as synonyms meaning "compounds consisting of a large number of monosaccharides linked glycosidically". However, in practice the term glycan may also be used to refer to the carbohydrate portion of a glycoconjugate, such as a glycoprotein, glycolipid, or a proteoglycan, even if the carbohydrate is only an oligosaccharide.

Any of various polysaccharides that are polymers of glucose and are components of the cell walls of plants, algae, fungi, and bacteria.

Any of a group of sugar molecules that are freestanding as oligosaccharides or polysaccharides or are combined in conjugates, as in glycoproteins.

(carbohydrate) Any polysaccharide that is a polymer of glucose

(cabrohydrate) Any polysaccharide or oligosaccharide, especially one that is part of a glycoprotein or glycolipid.