Natural product to modern discovery of their active ingredients and eventually to the development of new drugs. A large number of currently prescribed drugs have been either directly derived from or inspired by natural products. A few representative examples are listed below. Some of the oldest natural product based drugs are analgesics. The bark of the willow tree has been known from antiquity to have pain relieving properties. This is due to presence of the natural product salicin which in turn may be hydrolyzed into salicylic acid. A synthetic derivative acetylsalicylic acid better known as aspirin is a widely used pain reliever.
Asa Gray Gray had to borrow money from his father. Soon he was able to repay his father and help his family by supplementing his income giving lectures outside of Harvard, including at the Lowell Institute. Gray was considered a weak lecturer, but because of his expert knowledge, he was highly regarded by his peers. His skills were better suited to teaching advanced rather than introductory classes. He also gained renown for his textbooks and high quality illustrations. Gray moved into what became known as the Asa Gray House in the Botanic Garden in the summer of 1844. It had been built