Isoprenoid monoterpene toxicity

Section 26.8 X fi-Thujone a toxic monoterpene present in absinthe Terpenes and related isoprenoid compounds are biosynthesized from isopentenyl pyrophosphate. 

Mono- and sesquiterpenes are the main constituents of the essential oils, while the other terpenes are constituents of balsams, resins, waxes, and rubber. Oleoresin is a roughly equal mixture of turpentine (85 % Cio-monoterpenes and 15 % C15- sesquiterpenes) and rosin (C2o-diterpene) that acts in many conifer species as a toxic material to invading insects and their pathogenic fungi [12]. A number of angiosperm species have inducible terpenoid defensive compounds (phytoalexins) [13]. These include both sesquiterpenoid and diterpenoid t)pes. Isoprenoid units are also found within the framework of other natural molecules. Thus, indole alkaloids, several quinones (vitamin K), alcohols (vitamin E, vitamin A formed from p-carotene), phenols, and isoprenoid alcohols (also known as terpenols or polyprenols) also contain terpenoid fragments. The biogenesis. 

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