Bicyclogermacrene synthase (EC 4.2.3.100, Ov-TPS4) is an enzyme with systematic name (2E,6E))-farnesyl-diphosphate diphosphate-lyase (bicyclogermacrene-forming). This enzyme catalyses the following chemical reaction
The enzyme from oregano (Origanum vulgare) gives mainly bicyclogermacrene with Mn<sup>2+</sup> as a cofactor.