How a tree is helping to cure AIDS

In September of 1987, Dr. John Burley, research botanist at the Arnold Arboretum, was exploring the tropical rain forests of northern Borneo, searching for new medicines from plants to fight cancer and AIDS. As he collected a sample of an unknown tree species for testing in the laboratories of the National Cancer Institute, he also created a herbarium specimen for the Arnold Arboretum. Four years later an extract from the sample was found to be effective in preventing the growth of the AIDS virus. When researchers returned to Borneo to collect more plant material, the forest had been cut down and the plant was gone.
Dr. Peter Stevens, a botanist at the Arnold Arboretum, studied the herbarium sheet and identified the specimen as the rare species Calophyllum lanigerum. With this identification, botanists have been able to locate trees of the same species growing in a botanical garden in Singapore. In 1993, scientists isolated the compound calanolide A, which inhibits the growth of AIDS virus and has now been synthesized in the laboratory. Consequently, calanolide A is in the preclinical drug development as a promising vaccine to prevent the spread of AIDS.