Terpenes and terpenoids are two classes of naturally occurring compounds that are formally derived from isoprene (1). Carbon 1 is called the head of the molecule; carbon 4 is called the tail. Since th...Terpenes and terpenoids are two classes of naturally occurring compounds that are formally derived from isoprene (1). Carbon 1 is called the head of the molecule; carbon 4 is called the tail. Since the isoprene molecule has five carbon atoms, the number of carbon atoms in the molecule of a terpene/terpenoid is a multiple of five. The difference between terpenes and terpenoids is that terpenes are hydrocarbons, whereas terpenoids contain oxygen.
