Artemisia annua and (À)-a-bisabolol from Matricaria recutita (German
chamomile). Addition of IPP to GPP produces 2E,6E-farnesylpyrophosphate (FPP), the precursor for all sesquiterpenes. Farnesylpyrophosphate
can cyclize by various cyclase enzymes in various ways, leading to the
production of a variety of sesquiterpenes. Some of these sesquiterpenes are
medicinally important bioactive compounds. For example, (À)-a-bisabolol
and its derivatives have potent anti-inflammatory and spasmolytic properties, and artemisinin is an antimalarial drug.
H
OH
(−)-α-Bisabolol
Structural types
Sesquiterpenes can be of various structural types, some of which are
presented with specific examples in the following table.
Major structural types
Specific examples
Simple farnesane-type
acyclic sesquiterpenes
trans-β-Farnesene
A potent aphid-repellant found in
hops and sweet potatoes
Furanoid farnesane
sesquiterpenes
O
O
O
H
Ipomeamarone
A phytoalexin
Cyclobutane and cyclopentane
sesquiterpenes
O
H
Cyclonerodiol
A fungal metabolite
Cyclofarnesane-type
sesquiterpenes
O
O
OH
OH
Abscisic acid
A plant-growth regulatory agent
6.5 TERPENOIDS
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