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Chemistry of Essential Oils
Published in K. Hüsnü Can Başer, Gerhard Buchbauer, Handbook of Essential Oils, 2020
Figure 6.23 shows a few of the many possibilities for biosynthesis of sesquiterpenoids from (E,E)-farnesyl pyrophosphate. Cyclization of the cation (132) to C-11, followed by loss of a proton gives all trans- or α-humulene (133), whereas cyclization to the other end of the same double bond gives a carbocation (134) with the germacrane skeleton. This is an intermediate in the biosynthesis of odorous sesquiterpenes such as nootkatone (135) and α-vetivone (137). β-Vetivone (137) is synthesized through a route that also produces various alcohols, for example, (138) and (139), and an ether (140) that has the eudesmane skeleton. Rearrangement of the germacrane carbocation (134) leads to a carbocation (141) with the guaiane skeleton, and this is an intermediate in the synthesis of guaiol (142). Carbocation (141) is also an intermediate in the biosynthesis of the a-patchoulane (143) and b-patchoulane (144) skeletons and of patchouli alcohol (145).
Types of Raw Incense
Published in Kerry Hughes, The Incense Bible, 2014
The main constituents of the essential oil of Vetiver are vetiverol, vetivone, khusimone, khusitone, terpenes (e.g., vetivenes), and sesquiterpenoids. The main polysaccharides present in vetiver grass are hemicelluloses (approximately 38 percent) and cellulose (approximately 27 percent). The protein content is about 5 percent, lignin 10 percent, and ash 3 percent (mainly silica) (Methacanon et al., 2003).
Chemical Constituents and Essential Oil Biogenesis in Vetiveria Zizanioides
Published in Massimo Maffei, Vetiveria, 2002
α-Vetivone (21), also known as isonootkatone, was obtained from Haiti oil of Vetiver via separation of the ketonic components with Girard’s T reagent and its structure has been established (Marshall and Andersen, 1967). α- and β-vetivones were also characterized from the Reunion oil by GLC (Nigam and Levi, 1962). Total synthesis of 21 was achieved from 2-isopropylidene-1, 3-propanediol in about 14 steps (Marshall and Warne Jr., 1971). The key step involved annelation of 4-isopropylidene-2-carbomethoxycyclohexanone with trans-3-penten-2-one to give the bicyclic enone with cis-related CH3 and COOCH3 substituents. 21 has also been reported from
Review of Antimicrobial and Other Health Effects in 5 Essential Oil Producing Grass Species
Published in Journal of Dietary Supplements, 2023
De Santana Campos et al. (2015) reported that 29, 50, and 100 µl ml−1 of vetiver grass oil was effective against the human and animal disease causing tick species [Amblyomma cajennense and Rhipicephalus (Boophilus) microplus].by decreasing egg production. They determined that vetiver grass oil consisted of khusimol, isovalencenol, α-vetivone, α-cadinol, β-vetivone, and zizanoic acid. Vetiver oil was shown to reduce the human and animal feeding sheep blowfly (Lucilia sericata Meigen) larvae by 93.33% (Khater et al. 2018). A combination of hairy basil, vetiver, and citronella oils in nano-emulsion may improve stability and extend mosquito protection (Nuchuchua et al. 2009). Arsenic is a carcinogen and vetiver grass has been found to tolerate medium amounts of arsenic and therefore may be useful as a phytoremediator from arsenic contaminated soils (Datta et al. 2011).