Selinenes are a group of closely related isomeric chemical compounds which are classified as sesquiterpenes. The selinenes all have the molecular formula C15H24 and they have been isolated from a variety of plant sources. α-Selinene and β-selinene are the most common and are two of the principal components of the oil from celery seeds.[1] γ-Selinene and δ-selinene are less common.