number of
carbon atoms
OPP
OPP
OPP
OPP
OPP
OPP
OPP
OPP
OPP
H
H
H
H
H
H
H
H
3
4
4
4
4
5 (GPP)
6 (FPP)
7 (GGPP)
8 (GFPP)
C 5
C 10
C 15
C 20
C 25
Fig. 5 Condensation reaction catalyzed by prenyltransferases to form polyprenyl diphosphates,
and structures of 5–8
1
H
H
OPP
– OPP
–
– H
+
H
heterolytic cleavage of
the diphosphate moiety
deprotonation to finalize
the cyclization reaction
8
Fig. 6 Cyclization reaction to form sesterbrasiliatriene (1). This reaction is catalyzed by the
type 1 terpene cyclase
Sesterterpenoids
5