The University of California, Berkeley, and the tiny, two-island Pacific Ocean nation of Samoa will share equally in royalties from an anti-AIDS drug called prostratin, in an agreement that could be a model for the development and commercialization of drugs resulting from ethnobotany efforts. Prostratin is extracted from the bark of the mamala tree and has long been used as a hepatitis treatment by native healers in Samoa, a nation inhabited by fewer than 200,000 people. Prostratin works by forcing the AIDS virus out of reservoirs in the body, which increases the efficacy of antiretroviral drugs. Jay Keasling will be leading efforts to isolate and clone the genes for prostratin. If a genetically engineered version of the drug is produced, the university and Samoa will share the proceeds.