As elucidated early by Vick and
Zimmerman [35] 6-PP biosynthesis in Trichoderma species could have a
first step that depends on the formation of 13-hydroperoxide from
linoleic acid. The lipoxygenase reaction is followed by β-oxidation and
isomerization to form 5-hydroxy-2, 4-decenoic acid. Afterwards,
internal lactonization on the C5 hydroxyl group with the carboxylic
group of the same molecule gives rise to 6-PP production. The
significant decrease in 6-PP production may be correlated to the fact
that the high concentration of 6-PP may activate the fungi metabolism
to reduce this concentration as a defense metabolism to avoid its toxic
effect [11,13,28]. On the other hand 6-PP may be transformed into
other compounds as mentioned before.