octyl methoxycinnamate

Octyl methoxycinnamate is the most common active ingredient in sunscreens for protection against UV-B rays.{{Cite web|last=Ngan|first=Vanessa|date=2012|title=Allergy to cinnamate|url=https://dermnetnz.org/topics/allergy-to-cinnamate|access-date=2021-10-18|website=DermNet NZ}} It may be combined with oxybenzone and titanium oxide.{{cite journal |doi=10.1039/B206338G |pmid=12661594 |title=An in vitro systematic spectroscopic examination of the photostabilities of a random set of commercial sunscreen lotions and their chemical UVB/UVA active agents |journal=Photochemical & Photobiological Sciences |volume=1 |issue=12 |pages=970–81 |year=2002 |last1=Serpone |first1=Nick |last2=Salinaro |first2=Angela |last3=Emeline |first3=Alexei V. |last4=Horikoshi |first4=Satoshi |last5=Hidaka |first5=Hisao |last6=Zhao |first6=Jincai |bibcode=2002PhPhS...1..970S |s2cid=27248506 }}

Studies have evaluated the efficacy of octyl methoxycinnamate in preventing postoperative peritoneal adhesions and determined that octyl methoxycinnamate covering peritoneal surfaces decreases adhesion formation. This effect is more notable when octyl methoxycinnamate is applied before the induction of trauma.{{Cite journal|last1=Aysan|first1=Erhan|last2=Bektas|first2=Hasan|last3=Kaygusuz|first3=Arslan|date=December 2009|title=Efficacy of octyl methoxycinnamate in preventing postoperative peritoneal adhesions: An experimental model|url=https://onlinelibrary.wiley.com/doi/10.1111/j.1447-0756.2009.01077.x|journal=Journal of Obstetrics and Gynaecology Research|language=en|volume=35|issue=6|pages=1102–1108|doi=10.1111/j.1447-0756.2009.01077.x|pmid=20025636|s2cid=24582333}}

Chromophore groups, such as C=C, C=O, and O-N=O, have loosely held electrons that are excited by radiation. Hence, octyl methoxycinnamate is able to absorb radiation when the electron energy level is increased to an excited state.{{Cite web|last=PubChem|title=Octinoxate|url=https://pubchem.ncbi.nlm.nih.gov/compound/21630|access-date=2021-11-13|website=pubchem.ncbi.nlm.nih.gov|language=en}}

The UV spectra of octyl methoxycinnamate contains a maximum at 310 nm.{{Cite web|last=PubChem|title=Octinoxate|url=https://pubchem.ncbi.nlm.nih.gov/compound/21630|access-date=2021-11-13|website=pubchem.ncbi.nlm.nih.gov|language=en}}

Olefin metathesis has been widely studied. One of the synthesis pathways for octyl methoxycinnamate includes cross metathesis. The high efficiency of the nitro-Grela catalyst has been used in the cross metathesis of trans-anethole with 2-ethylhexyl acrylate to produce octyl methoxycinnamate (86% yield).{{Cite journal|last1=Kaczanowska|first1=Katarzyna|last2=Trzaskowski|first2=Bartosz|last3=Peszczyńska|first3=Aleksandra|last4=Tracz|first4=Andrzej|last5=Gawin|first5=Rafał|last6=Olszewski|first6=Tomasz K.|last7=Skowerski|first7=Krzysztof|date=2020|title=Cross metathesis with acrylates: N-heterocyclic carbene (NHC)- versus cyclic alkyl amino carbene (CAAC)-based ruthenium catalysts, an unanticipated influence of the carbene type on efficiency and selectivity of the reaction|journal=ChemCatChem|language=en|volume=12|issue=24|pages=6366–6374|doi=10.1002/cctc.202001268|s2cid=225155345|issn=1867-3899|doi-access=free}}

{{more medical citations needed|section|date=April 2013}}

One study performed in 2000 raised safety concerns about octyl methoxycinnamate by demonstrating toxicity to mouse cells at concentrations lower than typical levels in sunscreens.[https://www.newscientist.com/article/mg16822591.900-sinister-side-of-sunscreens.html Sinister side of sunscreens], Rob Edwards, New Scientist, 7 October 2000{{cite journal |doi=10.1093/oxfordjournals.rpd.a033219 |id={{INIST|1532995}} |title=Toxicity and Phototoxicity of Chemical Sun Filters |journal=Radiation Protection Dosimetry |volume=91 |pages=283–6 |year=2000 |last1=Butt |first1=S.T. |last2=Christensen |first2=T. }}{{Medcn|date=April 2013}} However, another study concluded that octyl methoxycinnamate and other sun screening agents do not penetrate the outer skin in sufficient concentration to cause any significant toxicity to the underlying human keratinocytes.{{cite journal |doi=10.1159/000085861 |pmid=15908756 |title=Sunscreen Penetration of Human Skin and Related Keratinocyte Toxicity after Topical Application |journal=Skin Pharmacology and Physiology |volume=18 |issue=4 |pages=170–4 |year=2005 |last1=Hayden |first1=C.G.J. |last2=Cross |first2=S.E. |last3=Anderson |first3=C. |last4=Saunders |first4=N.A. |last5=Roberts |first5=M.S. |s2cid=7914504 }}

Estrogenic and neurological effects were noted in laboratory animals at concentrations close to those experienced by sunscreen users{{cite book |first=Marta Axelstad |last=Petersen |type=PhD Thesis |year=2011 |title=Thyroid hormone disrupting chemicals and their influence on the developing rat brain |publisher=DTU Food, National Food Institute |isbn=978-87-92158-94-9 |oclc=826386040 |url=http://orbit.dtu.dk/en/publications/thyroid-hormone-disrupting-chemicals-and-their-influence-on-the-developing-rat-brain(de54df85-73cf-4570-a8a4-1a6a0fb28ffb).html }}{{page needed|date=June 2017}}{{cite journal |doi=10.1016/j.taap.2010.10.031 |pmid=21059369 |title=Effects of pre- and postnatal exposure to the UV-filter Octyl Methoxycinnamate (OMC) on the reproductive, auditory and neurological development of rat offspring |journal=Toxicology and Applied Pharmacology |volume=250 |issue=3 |pages=278–90 |year=2011 |last1=Axelstad |first1=Marta |last2=Boberg |first2=Julie |last3=Hougaard |first3=Karin Sørig |last4=Christiansen |first4=Sofie |last5=Jacobsen |first5=Pernille Rosenskjold |last6=Mandrup |first6=Karen Riiber |last7=Nellemann |first7=Christine |last8=Lund |first8=Søren Peter |last9=Hass |first9=Ulla |bibcode=2011ToxAP.250..278A }} and were also shown in vitro.{{citation needed|date=June 2017}} Octyl methoxycinnamate has been shown to be light sensitive with a decrease in UV absorption efficiency upon light exposure.{{Cite journal |last1=Pattanaargson |first1=Supason |last2=Munhapol |first2=Thitinun |last3=Hirunsupachot |first3=Piyawan |last4=Luangthongaram |first4=Pamornwan |date=2004-01-30 |title=Photoisomerization of octyl methoxycinnamate |url=https://www.sciencedirect.com/science/article/pii/S101060300300282X |journal=Journal of Photochemistry and Photobiology A: Chemistry |language=en |volume=161 |issue=2 |pages=269–274 |doi=10.1016/S1010-6030(03)00282-X |bibcode=2004JPPA..161..269P |issn=1010-6030|url-access=subscription }} This degradation causes formation of the Z-octyl-p-methoxycinnamate from the E-octyl-p-methoxycinnamate. In contrast, the OMC does not show degradation when kept in darkness for extended periods of time.{{citation needed|date=June 2017}}

A study carried out in 2017 by the Research Centre for Toxic Compounds in the Environment at Masaryk University, Czech Republic, indicates that octyl methoxycinnamate (EHMC) may damage human cell DNA. When exposed to sun rays, the spatial arrangement of its molecules changes and isomerisation takes place. While until now only unchanged EHMC has been researched, Massaryk University researchers focused on its isomers and found out that it has a significant genotoxic effect under lab conditions. It means that it may potentially damage human DNA and cause genome mutations which may lead to serious health risks.{{cite journal |doi=10.1016/j.scitotenv.2017.03.043 |pmid=28340478 |title=Different DNA damage response of cis and trans isomers of commonly used UV filter after the exposure on adult human liver stem cells and human lymphoblastoid cells |journal=Science of the Total Environment |volume=593-594 |pages=18–26 |year=2017 |last1=Sharma |first1=Anežka |last2=Bányiová |first2=Katarína |last3=Babica |first3=Pavel |last4=El Yamani |first4=Naouale |last5=Collins |first5=Andrew Richard |last6=Čupr |first6=Pavel |bibcode=2017ScTEn.593...18S }}

In swimming pools with hypochlorite in aqueous solution, octyl methoxycinnamate has been shown to produce chlorine-substituted intermediates. The chlorination intermediates of octyl methoxycinnamate demonstrated weak mutagenic effects on the Salmonella typhimurium TA 100 strain. The reactions depended on the pH, compound structures, and chlorine dose.{{Cite journal|last1=Nakajima|first1=Mariko|last2=Kawakami|first2=Tsuyoshi|last3=Niino|first3=Tatsuhiro|last4=Takahashi|first4=Yasuo|last5=Onodera|first5=Sukeo|date=2009|title=Aquatic Fate of Sunscreen Agents Octyl-4-methoxycinnamate and Octyl-4-dimethylaminobenzoate in Model Swimming Pools and the Mutagenic Assays of Their Chlorination Byproducts|url=http://www.jstage.jst.go.jp/article/jhs/55/3/55_3_363/_article|journal=Journal of Health Science|language=en|volume=55|issue=3|pages=363–372|doi=10.1248/jhs.55.363|issn=1344-9702|doi-access=free}}

Concern about effects on coral reefs resulted in a bill in the state legislature of Hawaii to limit use of sunscreens containing octyl methoxycinnamate and oxybenzone.{{Citation |last=Bever |first=Lindsey |date=2018-05-03 |title=Hawaii might be about to ban your favorite sunscreen to protect its coral reefs |newspaper=The Washington Post |url=https://www.washingtonpost.com/news/energy-environment/wp/2018/05/02/hawaii-might-be-about-to-ban-your-favorite-sunscreen-to-protect-its-coral-reefs/ |access-date=2018-05-03 |postscript=.}}{{Cite journal|last1=Galamgam|first1=Jayden|last2=Linou|first2=Natalia|last3=Linos|first3=Eleni|date=1 November 2018|title=Sunscreens, cancer, and protecting our planet|journal=The Lancet Planetary Health|volume=2|issue=11|pages=e465–e466|doi=10.1016/S2542-5196(18)30224-9|pmid=30396433|doi-access=free}}

For the same reasons, the government of Palau signed a law in 2018 (becoming effective in 2020) that restricted the sale and use of sunscreen and skincare products that contain a list of ten different chemicals, including the UV filters octyl methoxycinnamate, oxybenzone and octocrylene, with fines of {{US$|1,000}} for retailers who violate the law and the power to confiscate such products from non-commercial users.{{cite news |last=McGrath |first=Matt |date=2018-11-01 |title=Coral: Palau to ban sunscreen products to protect reefs |url=https://www.bbc.co.uk/news/science-environment-46046064 |work=BBC |access-date=2018-11-02 }}

Octinoxate contains a stereocenter and a double bond. It has the following stereoisomersS. Pattanaargson, T. Munhapol, P. Hirunsupachot, P. Luangthongaram (ed.): Photoisomerization of octyl methoxycinnamate. In: Journal of Photochemistry and Photobiology A: Chemistry , Elsevier Verlag, vol. 161, no. 2-3, 30 January 2004, pp. 269-274.Process for producing 2-ethylhexanol: [https://patents.google.com/patent/EP0216151B1 CL = DE 3530839A1], 29 August 1985; [https://patents.google.com/patent/DE3530839A1/en EP 0216151 B1], 20 August 1986. Therefore, octinoxate could consist of the following four stereoisomers:

• Amiloxate, a chemically related sunscreening agent
• Cinoxate, another cinnamic acid based sunscreen ingredient
• {{annotated link|Avobenzone}}

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Category:Cinnamate esters

Category:4-Methoxyphenyl compounds

Category:Sunscreening agents

Category:2-Ethylhexyl esters