Science Alive: Percy Julian

Physostigmine and Glaucoma

Together at DePauw University, Percy Julian and Josef Pikl worked on chemicals found in plants. They were really interested in a chemical called physostigmine.

In nature, physostigmine is found in Calabar beans, poisonous beans that grow in West Africa. Doctors knew for a long time that physostigmine was an effective treatment for glaucoma, a disease that causes blindness, but natural physostigmine was expensive. Calabar beans were hard to grow, each bean contained only a tiny amount of physostigmine, and it was hard to extract it from the beans. If Julian and Pikl could figure out how to synthesize physostigmine in the lab, it would then become much cheaper to produce on a large scale, and more people could afford to use it.

But they were in a race to make the drug . In England, the scientist Robert Robinson—a future Nobel Prize winner—was hard at work trying to synthesize physostigmine in his own lab. Because he was a world-famous chemist, most people expected Robinson to win the race to synthesize the drug first.

In fact, Robinson thought he had won, and he wrote a paper to share his results with other scientists. Julian and Pikl read his paper, but they believed that Robinson's proposed synthesis, in fact, could not produce physostigmine

. Moreover, Julian and Pikl really had made synthetic physostigmine, and they could prove it. They’d won a race against one of the best chemists in the world, and in 1935 scientists everywhere took notice of what Julian and Pikl had accomplished. They had discovered the way to make physostigmine inexpensively and opened the door to the affordable treatment of glaucoma.