Question

50 years ago, pregnant women who have prescribed thalidomide for morning sickness gave birth to children with birth defects. Thalidomide is a mixture of two enantiomers; one reduces morning sickness, but the other causes severe birth defects. Today, the FDA has approved this drug for non-pregnant individuals with Hansen's disease (leprosy) or newly diagnosed multiple myeloma, a blood and bone marrow cancer. The beneficial enantiomer can be synthesized and given to patients, but over time, both the beneficial and the harmful enantiomer can be detected in the body. Propose a possible explanation for the presence of the harmful enantiomer.

Short answer

One probable reason is that the body's contact with the drug led it to transform into its mirror image.

Step-by-step solution

Meaning of enantiomers

Enantiomers are compounds that are opposed to one another. They are, in other words, one of the two stereoisomers of a chemical compound that is the mirror image of the other.

Enantiomers of compounds cannot be superimposed on each other. It occurs when a molecule has two structures, and that are mirror images of each other due to a chiral carbon.

Effect of enantiomers on the biological system

The effects of two different enantiomers of the same chemical molecule on various organisms can be significantly different. This phenomenon is frequently observed in human reactions to a variety of drugs, including thalidomide.

Only one drug's enantiomers can induce the intended physiological changes, while the other enantiomer is commonly inactive or even harmful to the organism's health. As a result, enantiomerically pure drugs are being produced.

Explanation for the presence of harmful enantiomer in the body

Harmful enantiomers are frequently found in the body, despite the use of pure good enantiomer medicines. This could be the result of metabolic responses in the body.

Enantiomers interact with the body once they are inside. Such interactions or biological reactions can transform a molecule into its inverse. This could lead to the development of more hazardous enantiomers over time.

As a result, both beneficial and toxic enantiomers can be found in the human body.