(E)-ò-Ocimene synthase (EC 4.2.3.106, ò-ocimene synthase, AtTPS03, ama0a23, LjEbetaOS, MtEBOS) is an enzyme with systematic name geranyl-diphosphate diphosphate-lyase ((E)-ò-ocimene-forming). This enzyme catalyses the following chemical reaction
This enzyme is widely distributed in plants, which release ò-ocimene when attacked by herbivorous insects.