Google is celebrating the life of Percy Lavon Julian with a doodle on its homepage today, his 115th birthday. He died from liver cancer in 1975 at the age of 76.
Julian is known as a brilliant chemist, who emerged from the Jim Crow South to pioneer chemical synthesis of medicinal drugs and human hormones like progesterone and testosterone from plants. He is credited as the first to synthesize the natural product of physostigmine. His work is said to have "laid the foundation" for the steroid drug industry's production of cortisone, other corticosteroids, and birth control pills."
In 1973, Julian became the second African-American to be inducted into the National Academy of Sciences. In 1990, he was inducted into the National Inventors Hall of Fame. Three years later he was honored with a USPS stamp.
Here's a Nova segment about him:
Read the Wikipedia article about him.
One of Julian's studies related to physostigmine is available here.