One of a pair of diastereomers. The two epimers have opposite configuration at only one stereogenic center out of at least two. All other stereogenic center in the molecules are the same in each.
(Examples)
● β-D-glucopyranose and β-D-mannopyranose
● α-D-glucopyranose and β-D-glucopyranose
Cf. enantiomer, diastereomer, isomer
