Sesquiterpenoids components

The result obtained by GC-MS, with the same SPME conditions, from the black thick balm of a crocodile mummy (sample 1400, Musee Guimet, Lyon, France) is presented in Figure 10.11. The composition of the extract is close to that of sample 1998 but phenolic compounds were not detected. The GC-MS chromatogram obtained with the same substance after acid methanolysis and silylation is presented in Figure 10.12. Except for the sesquiterpenoids eluted between 10 min and 22 min, the observed compounds originate from a beeswax. The biomarkers of this substance are hexadecanoic acids hydroxylated in position 14 or 15 and long chain hydrocarbons, acids and alcohols eluted between 50 min and 90 min. Diterpenoid or triterpenoid resin components are not observed. 

F. Ewing. 5-Epi-aristolochene is a common precursor of the sesquiterpenoid phytoalexins capsidiol and debneyol. Phytochemistry 1989 28(3) 775-779. Borys, D. J., S. C. Setzer, L. J. Ling. CNS depression in an infant after the ingestion of tobacco A case report. Vet Hum Toxicol 1988 30(1) 20-22. Deutsch, H. M., K. Green, and L. H. Zalkow. Water soluble high molecular weight components from plants with potent intraocular pressure lowering activity. Curr Eye Res 1987 6(7) 949-950. 

The oil is sometimes incorrectly called West Indian sandalwood oil. However, its composition and odor are different from those of the oils obtained from sandalwood species. The major components of amyris oil are sesquiterpenoids such as elemol [639-99-6], /3-eudesmol [473-15-4], and epi-7-eudesmol [15051-81-7] [241-244]. 

Angelica root Angelica archangelica L. 15-Pentadecanolide, 13-tridecano-lide as characteristic minor components in addition to terpenoids and sesquiterpenoids (about 90)... 

Figure 6.10 De novo biosynthesis of isoprenoid pheromone components by bark and ambrosia beetles through the mevalonate biosynthetic pathway. The end products are hemiterpenoid and monoterpenoid pheromone products common throughout the Scolytidae and Platypodidae (Figure 6.9A). The biosynthesis is regulated by juvenile hormone III (JH III), which is a sesquiterpenoid product of the same pathway. The stereochemistry of JH III is indicated as described in Schooley and Baker (1985). Although insects do not biosynthesize sterols de novo, they do produce a variety of derivatives of isopentenyl diphosphate, geranyl diphosphate, and farnesyl diphosphate. Figure adapted from Seybold and Tittiger (2003).

GC-MS analysis to study the content and composition of extracts of celery revealed the presence of terpenoids, sesquiterpenoids and phthalides in the essential oils and extracts obtained with organic solvents from two celery cultivars (Wolski et al., 2004). The composition of the essential oil obtained from the fruits of three A. graveolens var. dulce cultivars, i.e. Helios, Orient and Zefir, showed that the main components of the essential oil were isoprenoids, including monoterpenes and sesquiterpenes. Essential oil content ranged from 2.5 to 3.0%. The percentage... 

Gerber has isolated (+ )-epicubenol (81) from a Streptomyces species. This compound is the enantiomer of that found in the essential oil of Cedrela toona Roxb. The syntheses of four naturally-occurring phenolic sesquiterpenoids obtained from the essential oil of elm wood have been reported, viz. (82 R = Me), (82 R = CHO), (83 R = Me), and (83 R = CHO). The known o-quinone, mansonone C (84), has also been isolated from elm wood. The structure (85) of sesquichamaenol, a minor component of the essential oil of Chamaecyparis forrnosensis, has been deduced on the basis of spectroscopic evidence and synthesis. Piers et al. have published complete details of their syntheses of a- and ) -cubebenes (86). 

This method has been applied to the identification of the metabolic product of a cryptic sesquiterpenoid biosynthetic pathway discovered by analysis of the S. coelicolor genome sequence, although it turned out that it was involved in the biosynthesis of a natural product known to be produced by other Streptomyces species." ° It has also been used to identify the products of a cryptic gene cluster identified in the complete genome sequence of Bacillus halodurans C-125 that was predicted to direct the biosynthesis of a two-component lantibiotic named haloduracin, which was identified in the culture supernatants of B. halodurans as well (Figure 9) (see Chapter 5.08)." ... 

The sesquiterpenoids that are important in odour terms mostly have complex cyclic structures. The problem of elimination of alcohols to produce olefins on attempted isolation is even more acute with sesquiterpenoids than with monoterpenoids because of their higher boiling points, which require more vigorous distillation conditions. The sesquiterpenoids responsible for the odours of vetiver and patchouli oils have complex structures which can only be reached by lengthy and hence uneconomic syntheses. Some of these components are shown in Figure 4.33. The vetivones are the major components of vetiver oil but contribute little to the odour. Minor components such as zizanal and khusimone are much more important. Similarly in patchouli oil, minor components such as nor-patchoulenol and nor-tetrapatchoulol are more important than the major constituent, patchouli alcohol. 

English, Texan or Chinese Cedarwood and their components are derived from the cedrane and thujopsane groups of sesquiterpenoids. Atlas and Himalayan cedarwoods are obtained from Cedrus species and their terpenoids are mostly from the bisabolane family. The cedrane/thujopsane derivatives are much more widely used than the bisabolanes. 

Laurencia species found off the coast of Australia and it may be of biosynthetic significance that the bromoeudesmane derivative (403) co-occurs with (404) (c/. Vol. 8, p. 101). A new component of the Hawaiian marine alga Laurencia nidifica has been identified as (-i-)-selina-4,7(l l)-diene (405) on the basis of spectroscopic evidence.Detailed chromatographic analysis of the sesquiterpenoid constituents of costus plant roots has revealed the presence of a-costol (406), y-costol (407), y-costal (408), and the elemene derivative (409). ... 

Typically, the oil will contain 45-47% of the a-isomer and 20-30% of the (3-isomer. Both isomers contribute to the distinctive woody odour of the oil. The (3-isomer is more intense and also contributes to the slightly animalic, urinous character of the oil. It is interesting to note that the odours of sandalwood and urine are closely related. One of the commonest parosmias (where an odorant is perceived differently by different subjects) is that of sandalwood and urine. Similarly, when a secondary alcohol with a sandalwood character is oxidised to the corresponding ketone, there is a high probability that the ketone will smell urinous. There are many other components in sandalwood oil, particularly sesquiterpenoids alcohols, aldehydes and hydrocarbons. Some of these make important contributions to the overall odour effect. 

A component of the defensive secretion of gyrinid beetles has been identified as the nor-sesquiterpenoid aldehyde gyrinidal (21). The odour... 

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