Noun
either one of a pair of compounds (crystals or molecules) that are mirror images on each other but are not identical
Source: WordNetIn nature, only one enantiomer of most chiral biological compounds, such as amino acids (except glycine, which is achiral), is present. Source: Internet
Skeletal formula of (R)-ketamine Ball-and-stick model of (R)-ketamine Skeletal formula of (S)-ketamine Ball-and-stick model of (S)-ketamine The optical rotation of a given enantiomer of ketamine can vary between its salts and free base form. Source: Internet
If the thumb points in the direction of the 4th substituent, the enantiomer is R. Otherwise, it's S. It is possible in rare cases that two substituents on an atom differ only in their absolute configuration (R or S). Source: Internet
This phenomenon is likely responsible for the poor correlation between NSAID efficacy and plasma concentration observed in older studies, when specific analysis of the active enantiomer was not performed. Source: Internet
The opposite D -enantiomer called D -ascorbate has equal antioxidant power, but is not found in nature, and has no physiological significance. Source: Internet
Dunitz citation describes how Pauling's first article on the theme in fact shows a left-handed helix, the enantiomer of the true structure. Source: Internet