for example, the drug penicillin was developed from simple bread mould . the medicine for malaria, quinine, comes from the cinchona tree. scientists have learned that over 1300 rainforest plants in the amazon have medicinal value . but only one plant species in a hundred has been tested for possible applications for human health . as the national cancer institute in the united states, a new program has been started to test plants from all over the world for their possible effects on cancer and aids