Abstract:Synthesis and functionalization of natural products are useful procedures to access and develop new and interesting molecules with biological properties. In this review we discuss the major sesquiterpenes isolated from the essential oil of cedar, which represents a family of abundant and inexpensive natural materials. Some total synthesis and chemical transformations described in the literature have been included.
“…The predominant compounds present in the fresh Cedrus atlantica oil were sesquiterpenes with the himachalene carbon skeleton generally found in the genus cedar [ 50 , 51 , 52 , 53 , 54 ], with the bicyclic sesquiterpene hydrocarbons α- γ- and β-himachalenes (#24, #29, #32) forming the largest peaks. Other constituents of the himachalane series, such as himachalene-1,4-diene (#30), α- and γ-dehydro-ar-himachalene (#33, #38), ar-himachalene (#39), oxidohimachalene (#47), (#55), and himachalol (#63) were detected in low amounts.…”
Biochemical and biomolecular archaeology is increasingly used to elucidate the consumption, use, origin, and trade of plants in the past. However, it can be challenging to use biomarkers to identify the taxonomic origin of archaeological plants due to limited knowledge of molecular survival and degradation for many key plant compounds in archaeological contexts. To gain a fundamental understanding of the chemical alterations associated with chemical degradation processes in ancient samples, we conducted accelerated degradation experiments with essential oil derived from cedar (Cedrus atlantica) exposed to materials commonly found in the archaeological record. Using GC-MS and multivariate analysis, we detected a total of 102 compounds across 19 treatments that were classified into three groups. The first group comprised compounds that were abundant in fresh cedar oil but would be unlikely to remain in ancient residues due to rapid degradation. The second group consisted of compounds that remained relatively stable or increased over time, which could be potential biomarkers for identifying cedar in archaeological residues. Compounds in the third group were absent in fresh cedar oil but were formed during specific experiments that could be indicative for certain storage conditions. These results show that caution is warranted for applying biomolecular profiles of fresh plants to ancient samples and that carefully designed accelerated degradation experiments can, at least in part, overcome this limitation.
“…The predominant compounds present in the fresh Cedrus atlantica oil were sesquiterpenes with the himachalene carbon skeleton generally found in the genus cedar [ 50 , 51 , 52 , 53 , 54 ], with the bicyclic sesquiterpene hydrocarbons α- γ- and β-himachalenes (#24, #29, #32) forming the largest peaks. Other constituents of the himachalane series, such as himachalene-1,4-diene (#30), α- and γ-dehydro-ar-himachalene (#33, #38), ar-himachalene (#39), oxidohimachalene (#47), (#55), and himachalol (#63) were detected in low amounts.…”
Biochemical and biomolecular archaeology is increasingly used to elucidate the consumption, use, origin, and trade of plants in the past. However, it can be challenging to use biomarkers to identify the taxonomic origin of archaeological plants due to limited knowledge of molecular survival and degradation for many key plant compounds in archaeological contexts. To gain a fundamental understanding of the chemical alterations associated with chemical degradation processes in ancient samples, we conducted accelerated degradation experiments with essential oil derived from cedar (Cedrus atlantica) exposed to materials commonly found in the archaeological record. Using GC-MS and multivariate analysis, we detected a total of 102 compounds across 19 treatments that were classified into three groups. The first group comprised compounds that were abundant in fresh cedar oil but would be unlikely to remain in ancient residues due to rapid degradation. The second group consisted of compounds that remained relatively stable or increased over time, which could be potential biomarkers for identifying cedar in archaeological residues. Compounds in the third group were absent in fresh cedar oil but were formed during specific experiments that could be indicative for certain storage conditions. These results show that caution is warranted for applying biomolecular profiles of fresh plants to ancient samples and that carefully designed accelerated degradation experiments can, at least in part, overcome this limitation.
“…This oil consists mainly of bicyclic sesquiterpene hydrocarbons, particularly 20% of -cis-and 50% -himachalene, respectively. 4 For sev-eral years, these sesquiterpenes have been the subject of research, especially their total synthesis 5 and their chemical transformation by different types of organic reactions such as gem-dihalogenocyclopropanation, alkene oxidation, halogenation addition, and hydrochlorination/dehydrohalogenation. [6][7][8] The epoxidation of himachalenes remains the most studied reaction since it provides new enantiomerically pure oxygenated compounds.…”
mentioning
confidence: 99%
“…[6][7][8] The epoxidation of himachalenes remains the most studied reaction since it provides new enantiomerically pure oxygenated compounds. 5 The selective reactivity of both double bonds of -and -himachalenes in different reaction conditions (epoxidation, gem-cyclopropanation, oxidation, etc. ) is of some interest.…”
mentioning
confidence: 99%
“…) is of some interest. 5 Indeed, epoxidation of -cis-and -himachalenes is stereo-and regioselective, the most substituted -side double bond being the most reactive. 4 In addition, the rearrangement of epoxides to carbonyl or nitrogen compounds represents an useful synthetic transformation, and hence several products could be obtained according to the nature of epoxides, catalysts, and reaction conditions.…”
Biosourced N-acetamide-based himachalenes were synthesized by Lewis acid catalyzed rearrangement of epoxy-himachalene derived from α-cis- and β-himachalenes, the main component of essential oil of Atlas cedar (Cedrus atlantica). Several new chiral polycyclic N-acetamide compounds were obtained with different selectivities depending on the acid used. Among the Lewis acids used, BF3·OEt2 under catalytic and mild conditions is efficient and selective affording the formation of chiral N-acetamides in good yields. Otherwise, using acetonitrile as solvent and reagent was proved as an efficient tool giving access to new N-acetamide-based himachalenes. A mechanism to explain the formation of the different compounds observed in the reaction mixture has also been proposed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.