Coronavirus: the quest for a pandemic pill

Will they find the cure the world is eagerly awaiting? Will they pinpoint the substance that will allow developing an effective antiviral to combat Sars-CoV-2? Will they be able to design a drug to mitigate the threat the coronavirus pandemic poses to the world? They might well succeed. After all, the refrigerators in Jürgen Seibel's laboratory are jam-packed with hundreds of tubes, plastic containers and glass bottles, each containing a different substance that could be the basis for developing an effective treatment for coronavirus.

Decades of experience in drug design

Jürgen Seibel is Professor of Organic Chemistry II at the Department of Chemistry and Pharmacy at the University of Würzburg. Drug design, the process of developing new medications, is one of his focal areas of research. For many years, he and his research team have been synthesising substances with the potential to develop new antibiotics or medicines to treat diseases such as measles, meningitis, tuberculosis and gonorrhoea. Now their focus is on Covid-19.

"When Germany went into lockdown, we knew that we had to extend our research efforts to include the novel coronavirus," Seibel explains. Looking for partners to test the substances developed in his lab on the virus, he found the perfect match at the Institute for Virology and Immunobiology of the University of Würzburg where Professor Jochen Bodem is researching Sars-CoV-2. He is capable of conducting the required experiments using cell cultures, scrupulously maintaining the highest safety standards.

First successes in cell cultures

Over the past years, Seibel and his team have successfully synthesised more than 1,000 molecules. These are now gradually being tested in the laboratory. The scientists have already identified several substances that significantly slowed down viral replication in cell tests — similar to the antiviral drug remdesivir which has already been approved and which scientists currently have high hopes for. "We were surprised how effective some of these molecules are," says Seibel.

For Seibel, however, the work does not end with cell experiments: "Once we know that a substance is effective, we examine it more closely and try to pinpoint the location where it takes effect. We then think about whether its structure can be modified to further boost its efficacy," Seibel adds.

A large arsenal of antiviral agents

There are many ways to prevent the virus from replicating, starting with the virus binding to the human cell and gaining entry, continuing with the multiple steps of viral replication inside the cell and ending only after the newly created viruses have left the cell. "Our goal is to identify potential vulnerabilities in all these steps and then design active agents that target them," the scientist says.

The drug to eliminate the virus is often thought of as the "key that fits the lock". But this definition is too narrow for Jürgen Seibel. He wonders — to stick with the metaphor — whether there are other completely different ways to open a door, even if it is just the ram that blows the lock. So instead of focusing on a handful of potential candidates, he has extended his search to include the entire pool of active antiviral substances — from lipids and peptides to sugars.

There will be other viruses

Despite the fact that some of the substances sitting in Seibel's laboratory refrigerator have already proved to be potentially effective, the scientist dampens too optimistic expectations. He expects that there is still a long way to go until his research will yield a marketable drug. Seibel is certain of one thing though: Finding a medicine will not be a problem. He has no doubts that this will work and that it is not relevant whether such a drug will be designed in a laboratory in Würzburg or elsewhere.

In Seibel's opinion, one of the few positive aspects about the pandemic is the fact that scientists all over the world are now pulling out all the stops to fight the novel coronavirus. He believes that this pooling of knowledge will considerably accelerate the process. Moreover, Seibel is convinced that any progress made in researching the virus will contribute to help humanity prepare for the next pandemic as he is certain that more dangerous viral diseases will follow after Sars-CoV-2.

Contact

Prof. Dr. Jürgen Seibel, Institute of Organic Chemistry, T: +49 931 31-85326, seibel@chemie.uni-wuerzburg.de