Scientific advancements sometimes mean the correction and alteration of previous discoveries and concepts. The Nobel Prize in Chemistry for the year 2021 involved such a revision. Benjamin List and David Macmillan, recipients of the 2021 Nobel Prize in Chemistry, secured their place in history not only for their discovery dating back to 2000, but also for managing to erase a bad name that had plagued science for many years.
They proved that the molecules could be artificially developed by a precise new process called asymmetric organocatalysis. This discovery, which could revolutionise the pharmaceutical industry, is paving the way for Chemistry itself to be less polluting, in its practical forms.They also proved that environment-friendly organic catalysts for organocatalysis could be produced quickly and inexpensively.
In July 1956, thalidomide was approved for human use in Germany. This drug, invented as a sedative for people with insomnia, was later used for colds and flu. Doctors around the world had begun to prescribe thalidomide as it was shown to be effective in relieving nausea and vomiting in pregnant women. However, in 1961 the drug was banned in Germany.
According to the article Thalidomide: The Tragedy of Birth Defects and the Effective Treatment of Disease written by James H. Kim and Anthony R. Scialli, thalidomide is known today as one of the greatest tragedies in medicine. As a side effect of this drug, many babies in different parts of the world died during pregnancy and some even died at birth. Tens of thousands of babies were born without limbs in Germany alone.
Carbon can form many more different compounds with other elements, than any other element.
However, thalidomide is used for some skin diseases and cancers, still. Questions have been raised as to whether such a drug was given to pregnant women without any trial. Despite having so many side effects, the question of why it is still used, remains. There is a connection between the answer to these questions and asymmetric organocatalysis.
Revolution in Organic Chemistry
Everything around us is made up of atoms, but they are not all the same. This is because of the different elements that make up the molecules. Two atoms of oxygen combine to form an oxygen molecule, and two atoms of hydrogen and one atom of oxygen combine to form a water molecule. Thus, molecules can vary from being small to very complex. Chemistry is divided into two branches based on the nature of the molecules – organic and inorganic.
Carbon can form many more different compounds with other elements, than any other element. This is possible because of the special structural properties of carbon. The study of this is also very relevant to Biology, because many of the chemical reactions that take place in our body are carried out by organic compounds.
The characteristic of some of these organic compounds is called chirality. According to ScienceDirect, chirality is the property of a molecule to have a non-superimposable mirror image. A chiral molecule cannot be superimposed on its mirror image and has a ‘handedness’ – think of shoes, which specifically go with the right or left foot.
Catalysts are substances that accelerate the chemical reaction without themselves undergoing a chemical change.
These compounds with opposite structure are called enantiomers. Thalidomide is such a compound. It has two enantiomers, S and R. Subsequent studies have shown that one of these causes side effects while the other acts as a drug. In the early days, it had gone unnoticed, ruining the lives of tens of thousands of children. Following this incident, the nations of the world decided to tighten drug trials.
The Nobel Prize in Chemistry for 2021 was awarded for the discovery of a new way of extracting only the useful chiral part from such mirror-image compounds. This process, pioneered by Benjamin List and David Macmillan, is called asymmetric organocatalysis.
Substitutes for enzymes
Catalysts are substances that accelerate the chemical reaction without themselves undergoing a chemical change. For a chemical reaction to take place, it must receive at least a small amount of energy. Catalysts modify the amount of this energy. There are generally two types of catalysts used in chemistry – one is enzyme, and the other is metal catalyst.
Enzymes speed up many of the chemical reactions in our bodies. For instance, consider the starch that we consume. Our body also has an enzyme system to convert the larger molecules into smaller molecules. Chemists have been able to recreate such functions of the body in the laboratory.
Accoring to the official website of the Nobel Prize, List and Macmillan discovered small organic compounds that could be used as catalysts instead of enzymes. As mentioned earlier, it has many benefits in the medical field as well. Many of the metal catalysts currently in use in the industrial sector have byproducts that are harmful or pollutes the environment. Asymmetric organocatalysis can solve this problem and change the catalysis process in the industrial sector to a more environment-friendly one.
Can thalidomide’s side effects be eliminated?
The Nobel Committee concluded that the components of many chemical processes can be reduced and that asymmetric organocatalysis is beneficial to all of humankind. Though Science has made great contributions to humankind, many chemical processes, including major disasters such as thalidomide, cause great damage to nature. Thalidomide is still seen as an effective remedy for diseases like cancer, leprosy etc. The scientific community hopes that the new findings could enable the elimination of many of its side effects.
Thalidomide can fight off germs in the body and maintain immunity. It can also reduce the formation of new blood cells, and that is why the risk of cancer cells multiplying is low. The United States Food and Drug Administration (FDA) has approved the use of thalidomide for diseases such as leprosy and multiple myeloma. However, its use is forbidden in pregnant women. It is also recommended that this medicine should be given to patients only after they are made aware of its side effects.
Thalidomide has some substitutes, but they also have side effects. Hopefully, the discovery by List and Macmillan will help in the development of drugs similar to thalidomide, which have no side effects. The thalidomide tragedy will always be a reminder that mistakes can happen in Science, too, but rectifying past mistakes and moving ahead is what Science does and must do.
Now put on your thinking hats and think about the following questions for a couple of minutes.
How would you describe the term “Thalidomide” to your students?
How would you describe the contributions of Benjamin List and David Macmillan in the development of asymmetric organocatalysis?
Write down your thoughts and discuss them with your students, children and your colleagues. Listen to their views and compare them with your own. As you listen to others, note how similar or different your views are to others’.
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