What is the function of chiral compounds in medicine?
1 Answer
Aug 21, 2016
A drug molecule must have the right chirality to match the corresponding shape in a biological molecule and have the desired effect.
Explanation:
Biological molecules are chiral, and the action of drugs depends on the matching the shapes of the drug and a biological molecule.
A drug of the wrong chirality may not fit, like putting a left hand into a right-handed glove.
More than half of current drugs are chiral compounds and almost 90% of them are 50:50 mixtures of enantiomers.
The body interacts with each enantiomer differently and generates different responses.
Thus, one isomer may produce the desired effects, while the other may be inactive or even produce undesired effects.
There are three types of racemic drugs:
- one enantiomer is active, and the other is inactive or produces undesired effects. For example,
#R# (-)-methadone is about 50 times more active than its enantiomer. - The two enantiomers are equally active. Only a few drugs belong to this group.
- One isomer is active, but one or both of them can be converted to the other enantiomer in the body. For example,
#S# -ibuprofen is 100 times more potent than (#R# )-ibuprofen, but only the inactive#R# -enantiomer is converted into the active#S# -enantiomer.
