Few stories characterize both the role of plants in modern science and the struggle for civil rights and equality than that of Percy Julian, the pioneering African-American chemist whose discoveries have changed the lives of millions of people around the world. Born in Montgomery, Alabama as the grandson of slaves, Julian was one of the few African-American students to receive an undergraduate degree from DePauw University in Indiana, where he graduated as valedictorian. He then went on to receive his M.S. from Harvard and his Ph.D. from the University of Vienna in Austria, after which he embarked on a career as one of the most influential research chemists of the twentieth century. Here we look at Percy Julian’s story through the discoveries he made connected to three plants – an Austrian species in the genus Corydalis, which is related to poppies, and two members of the pea family – the benign and ubiquitous soybean and the deadly and much rarer Calabar bean.
Julian’s success is especially inspiring, and all the more remarkable, considering the racial discrimination that plagued him through much of his life. Although he worked briefly as a highly gifted teacher and researcher the Board of Trustees at his alma mater, DePauw University, refused to hire him as a permanent faculty member because of his race. Another job fell through because a Wisconsin town would not allow African Americans on its premises after dark. Still later, when Percy Julian and his family moved to the then predominately white Chicago suburb of Oak Park, their home was fire-bombed. But through all of these setbacks, Julian managed to succeed in business and also became a successful researcher whose medicinal discoveries have provided huge benefits to people around the world.
Following his undergraduate career at DePauw and a master’s degree from Harvard, Julian received a scholarship to attend the University of Vienna for his PhD. There he made one of his first major scientific discoveries. People had known that Corydalis could be used for treating heart pains and palpitations, but Julian set out to discover the details of the chemistry responsible for these beneficial effects. In 1931, he succeeded in determining the structure of the three key chemical compounds that lead to Corydalis’ pain-relieving properties: hydro-hydrastinin, tetrahydrocoptisin, and canadine. He received his doctorate for this work, which set him on a course for his future pharmaceutical discoveries. These compounds are still used in some blood pressure reduction medicines today.
After a brief and tumultuous tenure at Howard University in Washington, D.C., Julian returned to DePauw University as a research fellow. There he accomplished another very important first, synthesizing a chemical derivative of the Calabar Bean from scratch. Julian viewed this project as a sort of make-or-break ordeal–something that, if successful, would establish him as a leader in chemistry, but that also potentially risked his career since Julian’s work contradicted the approach taken by one of his more eminent contemporaries. Julian succeeded. The compound he was able to make, physostigmine, based on the naturally occurring form he isolated from the calabar bean, is still used to treat glaucoma.
Despite his many scientific successes, Percy Julian continued to face discrimination and potential employers pulled their support when they saw the color of his skin. Following the end of his term at DePauw, he found himself once again looking for work, a task in which he encountered many obstacles because of his race. But in 1936, the pharmaceutical company Glidden offered Julian a position as head of one of its new research labs in Chicago, one focused around soybeans.
Working for Glidden, Julian achieved a succession of pivotal and commercially successful discoveries. Especially important was his discovery of a new approach to manufacturing the human hormones, progesterone, estrogen and testosterone from compounds called sterols isolated from soybean oil. Like many drug discoveries, from penicillin to taxol, serendipity was important. Noticing that water had leaked into a tank of valuable soybean oil – an accident that ruined hundreds of thousands of dollars of product and which could have cost him his job – Julian recognized that the crystals formed in the mixture could have promising properties. He later showed that they were an excellent starting point for the manufacture of steroids.
Julian and other researchers had been searching for a way to create human steroids for some time, because previously steroidal hormones could only be manufactured in small quantities, and at considerable expense, from animal sources. Julian’s discovery allowed Glidden to produce the steroid cheaply and in large quantities. Compounds such as progesterone, which Percy Julian discovered could be derived from the humble soybean, could be used to ease pregnancy and prevent miscarriages. This opened the way for the widespread manufacture of human hormones that are deployed in many different applications from contraceptive pills to uterine cancer treatments to hormone replacement therapy. These discoveries advanced modern medicine in dramatic ways, but they also testify to the powerful story of Julian himself: someone of great talent, who persisted with his research against many obstacles. In the end, his career was a triumph. Percy Julian was the second African American elected to the National Academy of Sciences, one of the most prestigious honors for any scientist. He is remembered to this day as one of the greatest research chemists of the twentieth century and as a role model and leader in the struggle for civil rights.