II.Terpenoids:
1- Monoterpenoid: two isoprene units (C10H16)
2- Sesquiterpenoids: three isoprene units(C15H24)
3- Diterpenoids: four isoprene units (C20H32)
4- Triterpenoids: six isoprene units (C30H48)
5- Tetraterpenoids: eight isoprene units(C40H64)