Chapter 26: Lipids
Terpenes
Terpenes commonly occur in the oils that give plants their fragrance.
Originally the term
terpene
was resricted to hydrocarbons, it is now used to include substituted derivatives too.
The fundamental building block of terpenes is the isoprene unit, C
5
H
8
The larger structures are "assembled" from several isoprene units, usually by "head-to-tail" linked isoprene units.
Question
What is the systematic name for isoprene ?
fundamental unit
a simple terpene
See how myrcene contains the skeletons
of 2 isoprene units connected head-to-tail
Terpenes can be cyclic or acyclic, with a large range of structural variations. A few examples are given below.
More than 23,000 terpene systems are known.
Monoterpenes are based on two isoprene units and so have the molecular formula C
10
H
16
Other terpenes have multiples of C
5
units so C
15
, C
20
, C
25
, C
30
etc
.
