Agar agar is made from Gelidium, Gracilaria, Pterocladia etc., Goiter medicine is made from Sargassum and Laminaria and Chloreline antibiotic is made from Chlorella. Galactans are produced from the red algae Callophyllis variegate and Agardhiella tenera. Galactans are used to prevent HIV. Oral cancer drugs are made from algae containing beta-carotene, which has antioxidant properties.