Percy Lavon Julian is considered one of the most influential chemists of the 20th century for his direct scientific contributions and his pivotal role in transforming plant compounds into affordable pharmaceuticals. His career was characterised by his ability to bridge the gap between rigorous academic research and broad industrial application, despite the structural and social barriers he faced as an African American scientist of that era.
Julian was born in Montgomery, Alabama, at a time when access to advanced education for African Americans was extremely limited. He attended DePauw University in Indiana, graduating with honours in 1920. Despite his brilliance, he was denied housing due to his race. He continued his studies, earning a master’s degree from Harvard University in 1923, but faced another obstacle: being denied a teaching assistantship. This prompted him to travel to Austria.
At the University of Vienna, Julian found an academic environment that allowed him to delve deeply into the chemistry of alkaloids. Under the supervision of Ernst Späth, he earned his doctorate in 1931, focusing his research on medicinal plants. This period laid the foundation for his subsequent international achievements in synthetic organic chemistry.
Julian returned to DePauw University as a researcher, where he achieved his first major scientific triumph in 1935. He successfully synthesised physostigmine in the laboratory, an alkaloid extracted from calabar beans and used to treat glaucoma. This achievement was a scientific challenge to the findings published by the renowned British chemist Sir Robert Robinson. Julian proved his method of synthesis to be correct, earning him international recognition as a first-rate organic chemist. This success demonstrated that complex natural substances could be reconstructed in the laboratory, paving the way for their commercial production.
Despite his academic achievements, Julian was denied a tenured professorship at DePauw University due to the prevailing racial discrimination of the time. These circumstances led him to the private sector, where he joined the Glidden Company in Chicago in 1936 as director of research in the soybean division.
At Glidden, Julian focused on extracting proteins and sterols from soybeans. This shift was pivotal in the history of industrial chemistry. He developed a process for isolating soy protein, which was used in paper coatings and paint production. Perhaps his most significant technical invention during this period was Aero-Foam, a substance derived from soy protein that was effectively used to extinguish oil and gas fires on warships during World War II, saving the lives of many sailors.
The biggest challenge Julian faced was producing steroid hormones at a low cost. At the time, obtaining substances like progesterone and testosterone required complex extraction processes from animal sources, making them expensive and limited in availability.
Julian discovered an innovative method for extracting stigmasterol from soybean oil in large quantities. Through precise chemical processes, he was able to convert this plant sterol into the hormone progesterone. This discovery enabled the large-scale production of artificial hormones, which later led to the development of birth control pills and fertility treatments.
In 1949, researchers at the Mayo Clinic announced the remarkable effectiveness of cortisone in relieving the symptoms of rheumatoid arthritis. However, producing cortisone required a 36-step chemical process starting with bovine bile acids, making it prohibitively expensive (hundreds of dollars per gram). Julian developed a method for synthesising ‘Complex S’ (a precursor to cortisone) from soybeans, significantly reducing the cost of producing cortisone and its derivatives, making them more affordable for ordinary patients.
In 1953, Julian decided to leave Gliden and establish his own company, Julian Laboratories. This was a major risk, as he faced difficulties in securing funding and obtaining raw materials. Nevertheless, he succeeded in building a chemical empire specialising in the production of intermediates for steroid drugs.
Julian expanded his operations to Mexico, where he discovered that wild yam contained diosgenin in higher concentrations than soybeans. He established a factory there to extract this substance, enabling him to compete with the world’s largest pharmaceutical companies. Later, in 1961, he sold his company for a substantial sum, becoming one of the first African American millionaires in the field of science. Alongside his scientific brilliance, Julian was a civil rights activist. In 1950, his home in Oak Park, Illinois, was bombed shortly after he moved in. This did not deter him from continuing his work and advocating for equality.
He used his platform to support rights organisations such as the NAACP and worked to recruit and train young minority chemists, believing that scientific excellence was a way to break down social barriers. He saw science as a universal language that transcended racial boundaries, but he also understood that access to laboratory work required legal and social struggles.
Percy Julian left behind more than 130 patents and published dozens of seminal scientific papers. He was elected to the National Academy of Sciences in 1973, an honour reflecting the magnitude of his scientific contributions.
Julian’s historical significance lies in his role as a bridge between natural organic chemistry and modern industrial chemistry. As a result of his contributions, steroids were transformed from rare and expensive materials into essential medicines produced in vast quantities. His approach to using renewable plant sources (such as soy and yams) as raw materials for the pharmaceutical industry was a cornerstone of green and sustainable chemistry decades before these terms even existed.
