Terpenes are a class of secondary metabolites found in plants and insects (such as termites or swallowtail butterflies). Terpenes are strong-smelling aromatic hydrocarbon which are used by plants/ insects to protect themselves by deterring parasites. They are secondary metabolites synthesized in plants. When a hydrogen or atoms of hydrogen, are replaced by other atoms such as oxygen, in a terpene compound, the terpene becomes a terpenoid (also known as isoprenoids). Terpenoids are a large and diverse class of naturally occurring organic chemicals, derived from five-carbon isoprene units assembled and modified in thousands of ways. They are multicyclic structures that differ from one another not only in functional group but also in their bas...