A member of the class of catechols that is benzene-1,2-diol substituted by a 2-hydroxyethyl group at position 4. Isolated from <em>Olea europaea</em>, it exhibits antioxidant and antineoplastic activities. ChEBI: Hydroxytyrosol is a member of the class of catechols that is benzene-1,2-diol substituted by a 2-hydroxyethyl group at position 4. Isolated from Olea europaea, it exhibits antioxidant and antineoplastic activities. It has a role as an antioxidant, a metabolite and an antineoplastic agent. It is a primary alcohol and a member of catechols. It is functionally related to a 2-(4-hydroxyphenyl)ethanol.