What does epimeric mean?
"Epimeric" is an adjective used almost exclusively in chemistry and biochemistry to describe a particular kind of relationship between stereoisomers — molecules with the same atoms connected in the same order but arranged differently in three-dimensional space. Two compounds are said to be epimeric when they differ in the configuration of just one chiral centre, a single carbon bearing four different groups. A familiar example involves the sugars glucose and galactose: they are identical except for the arrangement around one carbon, making them epimers of each other and therefore an epimeric pair. The word derives from Greek roots meaning "upon" and "part," reflecting how an epimer differs in only part of its structure. Because it names such a precise structural distinction, "epimeric" is indispensable in discussions of carbohydrate chemistry, enzyme specificity, and drug development, where small stereochemical differences can produce dramatically different biological effects.
adjectiveRelating to or consisting of epimers — stereoisomers that differ in the configuration of a single chiral centre. Used chiefly in chemistry and biochemistry to describe such isomeric compounds and the relationships between them.
- Of two or more chemical compounds: differing from each other in the configuration of exactly one chiral (stereogenic) centre; relating to or constituting epimers.
- (More broadly) Relating to or involving epimers or epimerism in stereochemistry.
"Glucose and galactose are epimeric sugars, differing only at one carbon atom."
"D-glucose and D-mannose are epimeric at the C-2 position."
"The enzyme interconverts the two epimeric forms of the sugar with high specificity."
Flip a single carbon atom in glucose and you get galactose — chemists call these near-twins "epimeric," and your body treats them very differently.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of epimeric
"Epimeric" comes from "epimer," a term coined in early 20th-century organic chemistry to denote stereoisomers differing at a single asymmetric carbon. The prefix "epi-" is Greek for "on" or "over," combined with "-mer" from Greek "meros," meaning "part." It thus shares its roots with words like "polymer" and "isomer." The adjective form follows standard English derivation with the suffix "-ic."
Related word forms
How epimeric is actually used
A technical term confined to chemistry, biochemistry, and related scientific literature; it does not appear in everyday speech. It typically appears attributively before nouns such as "forms," "relationship," or "mixture."
Easily confused with epimeric
"Anomeric" refers specifically to isomers differing at the anomeric carbon of a sugar's cyclic form, whereas "epimeric" describes isomers differing at any single chiral centre.
"Enantiomeric" describes mirror-image isomers, while "epimeric" describes diastereomers differing at just one stereocentre.