Patent ID: 8859757

Claim:
A separating agent for optical isomers that contains a polysaccharide derivative, wherein the polysaccharide derivative is provided by replacing all or a portion of hydrogen atoms on hydroxyl groups present in a cellulose or an amylose with the atomic groups represented by Formulae (1) and (2) below, and a sum of the average introduction ratios per monosaccharide unit of R1 and R2 in Formulae (1) and (2) below is greater than 3.0 but not more than 5.0: wherein, R1 and R2 each represent a C 1-18 monovalent aliphatic group which may have substituent selected from the group consisting of a C 1-18 alkyl group, an amino group, a halogen and a C 1-18 alkoxyl group or a C 6-18 monovalent aromatic group which may have substituent selected from the group consisting of a C 1-18 alkyl group, an amino group, a halogen and a C 1-18 akoxyl group and X represents an amide bond.