The Roots of Modern Medicine

The natural world has long served as humanity’s pharmacy. Largely discovered through trial and error, the medicinal benefits of plants, fungi, bacteria and animals have been crucial to our survival and will continue to provide inspiration for new medical advances. 

Perhaps the most transformative and well-known example is the discovery of antibiotics. Before the 20th century, a simple infection or case of pneumonia could be a death sentence. That changed in 1928 when Alexander Fleming discovered that a common mold was killing bacteria growing in his petri dish. The compound responsible, penicillin, has since saved countless lives. 

Another example is salicylic acid, a compound found in willow tree bark. Extract from willow bark was found to soothe pain and reduce inflammation as early as 3,500 years ago. At the end of the 19th century, scientists developed a more powerful synthetic derivative of this acid: acetylsalicylic acid, better known today as aspirin, the most used drug in the world. More recently, new breakthroughs in diabetes treatment and weight loss are rooted in a molecule found in Gila monster venom. 

Why does nature produce such effective medicines? The answer lies in evolution. Over millions of years, living organisms have evolved to produce an astonishing variety of molecules for their own survival. Unlike many drugs specifically designed in a laboratory, many natural molecules interact with human biological processes with less predictability, and we as scientists have learned to harness those beneficial coincidences. My translational chemistry research group at Northwestern is dedicated to understanding natural compounds, unlocking their secrets and using them to address some of the most difficult medical challenges of our time. 

Natural compounds have been transformative in cancer treatment, for example. In fact, it is estimated that over half of current chemotherapies are derived from or inspired by nature. 

The ability to divide indefinitely is one of the most troubling properties of cancer cells. Healthy cells have a built-in limit on the number of times they can divide, which acts as a natural safeguard against age-related damage and uncontrolled growth. Cancer cells can switch off this limit, becoming virtually immortal. 

My lab has identified new compounds derived from chrolactomycin — a natural product found in soil bacteria — that block this mechanism, shutting down the cancer cells’ immortality switch while leaving healthy cells unaffected. This selectivity is crucial: An effective cancer treatment must distinguish between a patient’s tumor cells, which need to be stopped, and healthy cells, which need to be protected. 

These examples share a powerful theme: Nature can show us how to modulate and control our own biology through chemistry. The molecules we study are not ready-to-go medicines waiting to be plucked from the forest, the soil or the sea. They are starting points — structurally precise molecules that have evolved over millennia and that guide us toward new medicines. 

At Northwestern we are integrating chemistry, biology and rapidly emerging computational resources to advance our discoveries toward the clinic. But even with the tools of modern science at our disposal, we continue to face challenges. Some debilitating diseases remain without a cure, while others are evolving resistance to current treatments. 

Our goal is to make the future of medicine brighter than ever. In our search for new medicines, nature remains our greatest inspiration and partner. 

Karl Scheidt is a professor of chemistry at Northwestern.