Names | |
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IUPAC name (1R,2R,5E,9Z)-1,5,9-trimethyl-12-propan-2-yl-15-oxabicyclo[10.2.1]pentadeca-5,9-dien-2-ol | |
Identifiers | |
3D model (JSmol) | |
ChemSpider | |
PubChem CID | |
CompTox Dashboard (EPA) | |
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| |
Properties [1] | |
C20H34O2 | |
Molar mass | 306.490 g·mol−1 |
Density | 1.0±0.1 g/cm3 |
Boiling point | 408.9±45.0 °C at 760 mmHg |
Vapor pressure | 0.0±2.2 mmHg at 25°C |
Refractive index (nD) | 1.493 |
Hazards | |
Flash point | 160.7±23.0 °C |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Incensole is a C20 diterpene alcohol and biomarker for some plants of the Boswellia genus. It, along with its acetate ester incensole acetate, is an abundant component of frankincense, the resin collected from Boswellia trees. [2] Incensole is used archaeologically to assist in identifying trade routes and distinguishing the identity of frankincense from other resins which may have been used together in incense and other salves. Incensole has also been deemed to be an active component in medicinal frankincense. [2]
Incensole was first isolated in 1966 at the University of Rome's Institute of Organic Chemistry by S. Corsano and R. Nicoletti while investigating the neutral components of Boswellia carteri resin. [3] There was some controversy as to whether the sample analyzed by S. Corsano and R. Nicoletti was actually from B. carteri and some believed that the original sample was from a B. papyrifera specimen. Further testing done by H. Obermann in 1977 identified an "Eritrea" type B. carteri sample (so named because it originated from the Eritrea region) which displayed incensole levels consistent with those found by Corsano and Nicoletti, but the sample specimen was likely B. papyrifera misidentified as B. carteri. [4] In 2005, incensole was used as a biomarker for frankincense (also known as olibanum) in order to determine the composition of Ancient Egyptian mummification balms and unguents, [5] speaking to its role in studying the history of religion.
Oily in appearance, incensole has low volatility. It can be synthetically prepared from cembrene, [6] a terpenoid, and cembrenol (serratol), its biologic precursor. [6] Diterpenes and terpenoids are classes of biomarkers which are synthesized in plants and have been found in insects, [7] possibly because of accumulation of terpenoids within their diets. [8] [ page needed ] Terpenoids have gained special interest due to their potential as anti-inflammatories, chemotherapies, and antiparasitics. [7]
It has been proposed that incensole is produced in Boswellia plants via serratol from geranylgeranyl pyrophosphate (GGPP), [4] a C20 precursor for many metabolic branches such as the chlorophyll, carotenoid, and gibberellin biosynthetic pathways. [9] To begin, GGPP loses its pyrophosphate group enabling it to be 1,14-cyclized to form cembrene after the loss of a proton. Cembrene is then hydrolyzed to form serratol which in turn undergoes epoxidation and intramolecular cyclization to form incensole. [4] Though this has been used to make incensole synthetically, [6] the abundances of incensole, serratol, incensole acetate, and iso-serratol in Boswellia species known to produce incensole are inconsistent with what would be expected if this pathway occurred in situ. [4]
Incensole is mainly found in the resin of Boswellia trees which grow in a region across Northern Africa from Ethiopia to Nigeria. [10] Boswellia trees prefer to grow in arid, stony regions, [10] and cuts to the body of the trees seep frankincense resin which hardens and darkens when exposed to the air.[ citation needed ] Incensole is a biomarker of frankincense from certain Boswellia species; these species are B. papyrifera , B. occulta, B. carteri, B. sacra , [5] [11] [12] [13] and possibly B. serrata though there are conflicting results as to whether it really produces incensole. [4] B. carteri and B. sacra have been determined to actually be the same species, except that B. carteri is native to Africa while B. sacra is native to South Arabia. [4]
It has also been proposed that incensole and incensole acetate can be derived from other sources such as these: [4]
Gas chromatography and mass spectrometry were used to identify incensole in these specimen, but to conclusively identify these species as producers of incensole/incensole acetate, isolation and structural elucidation from these species would have to occur. [4]
Incensole was originally isolated in 1966 by S. Corsano and R. Nicoletti using several ether extractions and vacuum separations, and then characterized using UV-Vis, IR, and H-NMR spectroscopy. They found incensole to have no UV-Vis absorption above 210 mμ. [3] The distinguishing IR and H-NMR peaks of incensole are reported in the tables below, [3] and the observed mass spectrum of incensole from a study done in 2014 on frankincense in incense pots is pictured to the right. [14]
Wave Number (cm−1) | Peak Identity |
---|---|
3620 | -OH |
1670 | C=C |
1375, 1390 | CH3-C-CH3 |
1050 | C-O |
Chemical Shift (ppm) | Protons [15] | Group Identity |
---|---|---|
0.90 | (d, 6H, J = 6.5 c/s) | isopropyl |
1.02 | (s, 3H) | CH3-C-O |
1.48, 1.61 | (s, 3H) | CH3-C= |
3.18 | (d, 1H, J = 10 c/s) | HC-OH |
5.06 | (2H, broad signal) | CH3CH=C(CH3)2 |
Incensole is most often extracted by chromatographic extractions and hydrodistillations, which produce a frankincense essential oil. Incensole is typically characterized by GC/MS although thin layer chromatography and near-infrared spectroscopy. [16] [4]
Unfortunately, within some of the earlier literature, frankincense biomarker compositions have been misattributed to different Boswellia species, as was seen in the mistaken attribution of the first extraction of incensole being from a B. carteri specimen when it likely came from a B. papyrifera specimen. This is likely because the taxonomic certifications for frankincense bought from market as opposed to collected straight from the tree are often faulty or absent. [4]
Frankincense has been used for thousands of years in religious ceremonies and for medicinal purposes. [2] In fact, by tracing incensole's degraded products, historians have been able to use it to understand the historical use of incense in religion. In one such case, the examination of incensole as a biomarker led to the identification of certain porous pots buried in medieval, Belgian, Christian graves as incense burners. Further study indicated that though frankincense was a main component of funerary incense at the time, other, cheaper local resins were mixed into the incense, possibly to reduce cost. [14]
Additionally, frankincense has been used for thousands of years as medicine. It is listed in texts such as the Papyrus Ebers and the Syriac book of medicine and was prescribed by the practitioners Celsus and Culpepper as a remedy for a variety of ailments from stomach ulcers and gastrointestinal hemorrhages to gout and open wounds. [13] Modern analysis on the medicinal efficacy of frankincense has revealed incensole and incensole acetate, along with boswellic acids, to be the bioactive ingredients of frankincense. [2]
Due to its religious and medicinal significance, frankincense and its biomarker components, like incensole, can be found all over the world in Europe, Asia, the Mediterranean, and the Middle East [2] [13] [17] as the result of global trade.
Previously, the therapeutic properties of frankincense had been attributed to boswellic acids within the resin, but research from 2019 and 2020 has found incensole and its acetate ester to be major contributors to frankincense's therapeutic efficacy. [2] This research has found incensole to act as an anti-inflammatory and neuroprotective compound after murine head-trauma on top of exhibiting anxiolytic, anti-depressive, and sedative effects in mice. [2]
It is proposed that incensole works as an anti-inflammatory through the inhibition of the NF-κB pathway which is responsible for the increased production of proinflammatory proteins. Insensitivity in the NF-κB pathway is correlated to arthritis, asthma, inflammatory bowel disease, ataxia telangiectasia, cancers, and neurodegenerative diseases. [2] [12] [18]
It has also been found that incensole acetate activates the TRPV3 channel [2] which is responsible for regulating wound healing and the perception of pain and itching, among other things. [19] It is thought that this is another key component of incensole's role as an anti-inflammatory agent.
Incensole has also been cited as a potential antibacterial against Bacillus. [12]
In polymer chemistry and materials science, a resin is a solid or highly viscous substance of plant or synthetic origin that is typically convertible into polymers. Resins are usually mixtures of organic compounds. This article focuses mainly on naturally occurring resins.
Myrrh is a gum-resin extracted from a few small, thorny tree species of the Commiphora genus, belonging to the Burseraceae family. Myrrh resin has been used throughout history in medicine, perfumery, and incenses. Myrrh mixed with posca or wine was widely used in many ancient cultures to produce pleasurable feelings and as an anti-inflammatory and analgesic.
Incense is an aromatic biotic material that releases fragrant smoke when burnt. The term is used for either the material or the aroma. Incense is used for aesthetic reasons, religious worship, aromatherapy, meditation, and ceremonial reasons. It may also be used as a simple deodorant or insect repellent.
Frankincense, also known as olibanum, is an aromatic resin used in incense and perfumes, obtained from trees of the genus Boswellia in the family Burseraceae. The word is from Old French franc encens. There are several species of Boswellia that produce true frankincense: Boswellia sacra, B. frereana, B. serrata, and B. papyrifera. Resin from each is available in various grades, which depends on the time of harvesting. The resin is hand-sorted for quality.
Boswellia is a genus of trees in the order Sapindales, known for its fragrant resin. The biblical incense frankincense is an extract from the resin of the tree Boswellia sacra, and is now produced also from B. frereana. Boswellia species are moderate-sized flowering plants, including both trees and shrubs.
Styrax is a genus of about 130 species of large shrubs or small trees in the family Styracaceae, mostly native to warm temperate to tropical regions of the Northern Hemisphere, with the majority in eastern and southeastern Asia, but also crossing the equator in South America. The resin obtained from the tree is called benzoin or storax, often used as a vanilla-like component in perfumery.
The Burseraceae are a moderate-sized family of 17-19 genera and about 540 species of woody flowering plants. The actual numbers given in taxonomic sources differ according to taxonomic revision at the time of writing. The Burseraceae are also known as the torchwood family, the frankincense and myrrh family, or simply the incense tree family. The family includes both trees and shrubs; its species are native to tropical regions of Africa, Asia, Australasia, and the Americas.
Iproniazid is a non-selective, irreversible monoamine oxidase inhibitor (MAOI) of the hydrazine class. It is a xenobiotic that was originally designed to treat tuberculosis, but was later most prominently used as an antidepressant drug. However, it was withdrawn from the market because of its hepatotoxicity. The medical use of iproniazid was discontinued in most of the world in the 1960s, but remained in use in France until its discontinuation in 2015.
Boswellic acids are a series of pentacyclic terpenoid molecules that are produced by plants in the genus Boswellia. Like many other terpenes, boswellic acids appear in the resin of the plant that exudes them; it is estimated that they make up 30% of the resin of Boswellia serrata. While boswellic acids are a major component of the resin, the steam or hydro distilled frankincense essential oil does not contain any boswellic acid as these components are non-volatile and too large to come over in the steam distillation process.
Commiphora myrrha, called myrrh, African myrrh, herabol myrrh, Somali myrrhor, common myrrh, is a tree in the family Burseraceae. It is one of the primary trees used in the production of myrrh, a resin made from dried tree sap. The tree is native to the Arabian Peninsula and to Africa. It is called 'mur' (المر) in Arabic, meaning bitter. It famously comes from Mecca, so it is called 'Mur Makki'.
Ferruginol is a natural phenol with a terpenoid substructure. Specifically, it is a diterpene of the abietane chemical class, meaning it is characterized by three fused six-membered rings and alkyl functional groups. Ferruginol was first identified in 1939 by Brandt and Neubauer as the main component in the resin of the Miro tree and has since been isolated from other conifer species in the families Cupressaceae and Podocarpaceae. As a biomarker, the presence of ferruginol in fossils, mainly resin, is used to describe the density of these conifers in that particular biosphere throughout time.
Boswellia sacra, also known as Boswellia carteri and others, and commonly called the frankincense tree or the olibanum tree, is a tree in the genus Boswellia, in the Burseraceae family, from which frankincense, a resinous dried sap, is harvested. The olibanum tree is plant native to the countries of Oman and Yemen, in the south of the Arabian Peninsula, and to Somalia, in the Horn of Africa.
Boswellia papyrifera, also known as the Sudanese frankincense, is a species of flowering plant and frankincense that is native to Ethiopia, Eritrea and Sudan. The tree is cultivated in Ethiopia because of its valuable resin. The incense is characterized by a fresh lemon-pine scent and is therefore highly esteemed. In Ethiopia where it is called itan zaf, it comes in semi-translucent yellow tears. The gum resin of Boswellia papyrifera coming from Ethiopia, Sudan and eastern Africa is believed to be the main source of frankincense of antiquity.
Aquilaria sinensis, known as incense tree, is a species of plant in the family Thymelaeaceae. It is endemic to China. It is threatened by habitat loss. This medicinal plant is a source of fragrant wood, formed under a pathological condition, called agarwood.
Arachidonate 5-lipoxygenase inhibitors are compounds that slow or stop the action of the arachidonate 5-lipoxygenase enzyme, which is responsible for the production of inflammatory leukotrienes. The overproduction of leukotrienes is a major cause of inflammation in asthma, allergic rhinitis, and osteoarthritis.
Transient receptor potential cation channel, subfamily V, member 3, also known as TRPV3, is a human gene encoding the protein of the same name.
Lupeol is a pharmacologically active pentacyclic triterpenoid. It has several potential medicinal properties, like anticancer and anti-inflammatory activity.
Bakuchiol is a meroterpenoid in the class terpenophenol.
Curzerene is a volatile, aromatic terpenoid found in many herbs and spices, such as Curcuma zeodaria. It is a bioactive isolate of Caribbean corals and is also found in myrrh. More specifically it has been found to make up a significant portion - 12.97% - of the smoke produced from burning Commiphora myrrha oleo gum resin. It is also a major component of myrrh oil, which has been shown in vitro to possess anti-inflammatory properties at sub-toxic by inhibiting the production of the inflammatory cytokine IL-6 by human gingival fibroblasts. Anecdotal evidence exists to support the anti-inflammatory effect of myrrh oil.
Kindeya Gebrehiwot is an Ethiopian academic who is currently Professor of Forestry at Mekelle University (Ethiopia), undertaking research on forest regeneration, particularly frankincense trees. He studies the threats to this flagship species, particularly in relation to regrowth and tapping. He was also President of Mekelle University.