Caryophyllene (/ˌkærioʊˈfɪliːn/), more formally (−)-β-caryophyllene (BCP), is a natural bicyclic sesquiterpene that occurs widely in nature. Caryophyllene is notable for having a cyclobutane ring, as well as a trans-double bond in a 9-membered ring, both rarities in nature. [3]
Production
Caryophyllene can be produced synthetically,[4] but it is invariably obtained from natural sources because it is widespread. It is a constituent of many essential oils, especially clove oil, the oil from the stems and flowers of Syzygium aromaticum (cloves), the essential oil of Cannabis sativa, copaiba, rosemary, and hops.[3] It is usually found as a mixture with isocaryophyllene (the cis double bond isomer) and α-humulene (obsolete name: α-caryophyllene), a ring-opened isomer.
Caryophyllene is one of the chemical compounds that contributes to the aroma of black pepper.[5]
Basic research
β-Caryophyllene is under basic research for its potential action as an agonist of the cannabinoid receptor type 2 (CB2 receptor).[6] In other basic studies, β-caryophyllene has a binding affinity of Ki = 155 nM at the CB2 receptors.[7]
β-Caryophyllene has the highest cannabinoid activity compared to the ring opened isomer α-caryophyllene humulene which may modulate CB2 activity.[8] To compare binding, cannabinol binds to the CB2 receptors as a partial agonist with an affinity of Ki = 126.4 nM,[9] while delta-9-tetrahydrocannabinol binds to the CB2 receptors as a partial agonist with an affinity of Ki = 36 nM.[10]
Safety
Caryophyllene has been given generally recognized as safe (GRAS) designation by the FDA and is approved by the FDA for use as a food additive, typically for flavoring.[11][12] Rats given up to 700 mg/kg daily for 90 days did not produce any significant toxic effects.[13] Caryophyllene has an LD50 of 5,000 mg/kg in mice.[14][15]
Metabolism and derivatives
14-Hydroxycaryophyllene oxide (C15H24O2) was isolated from the urine of rabbits treated with (−)-caryophyllene (C15H24). The X-raycrystal structure of 14-hydroxycaryophyllene (as its acetate derivative) has been reported.[16]
The metabolism of caryophyllene progresses through (−)-caryophyllene oxide (C15H24O) since the latter compound also afforded 14-hydroxycaryophyllene (C15H24O) as a metabolite.[17]
Caryophyllene oxide,[18] in which the alkene group of caryophyllene has become an epoxide, is the component responsible for cannabis identification by drug-sniffing dogs[19][20] and is also an approved food additive, often as flavoring.[12] Caryophyllene oxide may have negligible cannabinoid activity.[21]
Natural sources
The approximate quantity of caryophyllene in the essential oil of each source is given in square brackets ([ ]):
^Corey, E. J.; Mitra, R. B.; Uda, H. (1964). "Total Synthesis of d,l-Caryophyllene and d,l-Isocaryophyllene". Journal of the American Chemical Society. 86 (3): 485–492. Bibcode:1964JAChS..86..485C. doi:10.1021/ja01057a040.
^ abJirovetz, L.; Buchbauer, G.; Ngassoum, M. B.; Geissler, M. (November 2002). "Aroma compound analysis of Piper nigrum and Piper guineense essential oils from Cameroon using solid-phase microextraction–gas chromatography, solid-phase microextraction–gas chromatography–mass spectrometry and olfactometry". Journal of Chromatography A. 976 (1–2): 265–275. doi:10.1016/S0021-9673(02)00376-X. PMID12462618.
• Asakawa, Y.; Taira, Z.; Takemoto, T.; Ishida, T.; Kido, M.; Ichikawa, Y. (June 1981). "X-Ray Crystal Structure Analysis of 14-Hydroxycaryophyllene Oxide, a New Metabolite of (—)-Caryophyllene, in Rabbits". Journal of Pharmaceutical Sciences. 70 (6): 710–711. doi:10.1002/jps.2600700642. PMID7252830. S2CID38358882.
^Yang, Depo; Michel, Laura; Chaumont, Jean-Pierre; Millet-Clerc, Joëlle (1999). "Use of caryophyllene oxide as an antifungal agent in an in vitro experimental model of onychomycosis". Mycopathologia. 148 (2): 79–82. doi:10.1023/a:1007178924408. PMID11189747. S2CID24242933.
^Stahl, E.; Kunde, R. (1973). "Die Leitsubstanzen der Haschisch-Suchhunde" [The tracing substances of hashish search dogs]. Kriminalistik (in German). 27: 385–389.
^Wiley, Jenny L.; Marusich, Julie A.; Blough, Bruce E.; Namjoshi, Ojas; Brackeen, Marcus; Akinfiresoye, Luli R.; Walker, Teneille D.; Prioleau, Cassandra; Barrus, Daniel G.; Gamage, Thomas F. (June 2024). "Evaluation of cannabimimetic effects of selected minor cannabinoids and Terpenoids in mice". Progress in Neuro-Psychopharmacology and Biological Psychiatry. 132: 110984. doi:10.1016/j.pnpbp.2024.110984. PMC 11015967. PMID38417478. S2CID267941924.
^Singh, G.; Marimuthu, P.; De Heluani, C. S.; Catalan, C. A. (January 2006). "Antioxidant and biocidal activities of Carum nigrum (seed) essential oil, oleoresin, and their selected components". Journal of Agricultural and Food Chemistry. 54 (1): 174–181. Bibcode:2006JAFC...54..174S. doi:10.1021/jf0518610. hdl:11336/99544. PMID16390196.
^Zheljazkov, V. D.; Cantrell, C. L.; Tekwani, B.; Khan, S. I. (January 2008). "Content, composition, and bioactivity of the essential oils of three basil genotypes as a function of harvesting". Journal of Agricultural and Food Chemistry. 56 (2): 380–5. Bibcode:2008JAFC...56..380Z. doi:10.1021/jf0725629. PMID18095647.
^Calvo Irabién, L. M.; Yam-Puc, J. A.; Dzib, G.; Escalante Erosa, F.; Peña Rodríguez, L. M. (July 2009). "Effect of postharvest drying on the composition of Mexican oregano (Lippia graveolens) essential oil". Journal of Herbs, Spices & Medicinal Plants. 15 (3): 281–287. doi:10.1080/10496470903379001. S2CID86208062.
^Umezu, T.; Nagano, K.; Ito, H.; Kosakai, K.; Sakaniwa, M.; Morita, M. (December 2006). "Anticonflict effects of lavender oil and identification of its active constituents". Pharmacology Biochemistry and Behavior. 85 (4): 713–721. doi:10.1016/j.pbb.2006.10.026. PMID17173962. S2CID21779233.
^Ormeño, E.; Baldy, V.; Ballini, C.; Fernández, C. (September 2008). "Production and diversity of volatile terpenes from plants on calcareous and siliceous soils: effect of soil nutrients". Journal of Chemical Ecology. 34 (9): 1219–1229. Bibcode:2008JCEco..34.1219O. doi:10.1007/s10886-008-9515-2. PMID18670820. S2CID28717342.
^Kaul, Pran N; Bhattacharya, Arun K; Rajeswara Rao, Bhaskaruni R; Syamasundar, Kodakandla V; Ramesh, Srinivasaiyer (1 January 2003). "Volatile constituents of essential oils isolated from different parts of cinnamon (Cinnamomum zeylanicum Blume)". Journal of the Science of Food and Agriculture. 83 (1): 53–55. Bibcode:2003JSFA...83...53K. doi:10.1002/jsfa.1277.