The next generation of anti-AIDS drugs could be based on a chemical extracted from green coffee beans, US researchers claim. Edward Robinson and his colleagues from the University of California made extracts from over 60 plants routinely used by medicine men of the Kallawaya tribes in Bolivia. They discovered that one of the extracts, chicoric acid, could prevent the human immunodeficiency virus (HIV) from replicating within human cells. HIV infects the human cells by integrating its own DNA into that of the host cell, a process governed by the enzyme HIV inter-grase. Chicoric acid interferes with this enzyme. The researchers hope to develop a drug based on a more powerful synthetic version of the chemical. The finding could be a major breakthrough in the treatment of AIDS, said Robinson. Current drug cocktails attack two other key enzymes responsible for promoting HIV replication, HIV protease and HIV reverse transcrip-tase. But severe side effects and viral resistance are limiting the effectiveness of these drugs. Chicoric acid could lead to the development of a new class of non-toxic AIDS drugs to which the virus has not developed resistance.