Trehalose is a disaccharide formed by a  bond between two α-glucose units. It is found in nature as a disaccharide and also as a monomer in some polymers. Two other isomers exist, α,β-trehalose, otherwise known as neotrehalose, and β,β-trehalose (also referred to as isotrehalose). Neotrehalose has not been isolated from a living organism. Isotrehalose is also yet to be isolated from a living organism, but was found in starch hydroisolates.