A compound of the formula (I):

wherein R¹ and R² are, independently, a hydrogen atom, a monosaccharide residue, a protected monosaccharide residue, or a protecting group for hydroxyl group, but at least one of R¹ and R² is a monosaccharide residue or a protected monosaccharide residue, and R³ is a hydrogen atom, a hydroxyl group, an alkyl group, an aryl group, or an aralkyl group, with the proviso that (1) when R¹ and R² are glucose residues at the same time, R³ is not a hydrogen atom, (2) when R¹ is a hydrogen atom, an acetyl group or a benzyl group and R² is a glucose residue, an acetylated glucose residue, or acetalized glucose residue, R³ is not a hydrogen atom, or (3) when R¹ is a glucose residue and R² is a hydrogen atom, R³ is not a hydrogen atom or a salt thereof is disclosed.