Names | |
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IUPAC name (RS)-2-Ethylhexyl (2E)-3-(4-methoxyphenyl)prop-2-enoate | |
Other names Ethylhexyl methoxycinnamate Octinoxate Uvinul MC80 (E)-3-(4-methoxyphenyl) prop-2-enoic acid 2-ethylhexyl ester | |
Identifiers | |
3D model (JSmol) | |
ChEMBL | |
ChemSpider | |
ECHA InfoCard | 100.157.824 |
PubChem CID | |
UNII | |
CompTox Dashboard (EPA) | |
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Properties | |
C18H26O3 | |
Molar mass | 290.403 g·mol−1 |
Density | 1.01 g/cm3 |
Melting point | −25 °C (−13 °F; 248 K) |
Boiling point | 198 to 200 °C (388 to 392 °F; 471 to 473 K) |
Pharmacology | |
D02BA02 ( WHO ) | |
Legal status |
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Hazards | |
NFPA 704 (fire diamond) | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Octyl methoxycinnamate or ethylhexyl methoxycinnamate (INCI) or octinoxate (USAN), trade names Eusolex 2292 and Uvinul MC80, is an organic compound that is an ingredient in some sunscreens and lip balms. It is an ester formed from methoxycinnamic acid and 2-ethylhexanol. It is a liquid that is insoluble in water.
It is primarily used in sunscreens and other cosmetics to absorb UV-B rays from the sun, protecting the skin from damage. It is also used to reduce the appearance of scars.
Octyl methoxycinnamate is the most common active ingredient in sunscreens for protection against UV-B rays. [2] [3] It may be combined with oxybenzone and titanium oxide. [2]
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. [4]
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. [5]
The UV spectra of octyl methoxycinnamate contains a maximum at 310 nm. [6]
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). [7]
This section needs more reliable medical references for verification or relies too heavily on primary sources .(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. [8] [9] [ medical citation needed ] 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. [10]
Estrogenic and neurological effects were noted in laboratory animals at concentrations close to those experienced by sunscreen users [11] [12] and were also shown in vitro.[ citation needed ] Octyl methoxycinnamate has been shown to be light sensitive with a decrease in UV absorption efficiency upon light exposure. [13] 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 ]
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. [14]
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. [15]
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. [16] [17]
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. [18]
Octinoxate contains a stereocenter and a double bond. It has the following stereoisomers [19] [20] Therefore, octinoxate could consist of the following four stereoisomers:
Enantiomers of Octinoxate | ||
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(R)-shape | (S)-shape | |
(E)-shape | ||
(Z)-shape |
Ultraviolet (UV) light is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight, and constitutes about 10% of the total electromagnetic radiation output from the Sun. It is also produced by electric arcs, Cherenkov radiation, and specialized lights, such as mercury-vapor lamps, tanning lamps, and black lights.
Oxybenzone or benzophenone-3 or BP-3 is an organic compound belonging to the class of aromatic ketones known as benzophenones. It takes the form of pale-yellow crystals that are readily soluble in most organic solvents. It is widely used in sunscreen formulations, plastics, toys, furniture finishes, and other products to limit UV degradation. In nature, it can be found in various flowering plants (angiosperms). The compound was first synthesised in Germany by chemists König and Kostanecki in 1906.
Sunscreen, also known as sunblock, sun lotion or sun cream, is a photoprotective topical product for the skin that helps protect against sunburn and prevent skin cancer. Sunscreens come as lotions, sprays, gels, foams, sticks, powders and other topical products. Sunscreens are common supplements to clothing, particularly sunglasses, sunhats and special sun protective clothing, and other forms of photoprotection.
4-Aminobenzoic acid (also known as para-aminobenzoic acid or PABA because the two functional groups are attached to the benzene ring across from one another in the para position) is an organic compound with the formula H2NC6H4CO2H. PABA is a white solid, although commercial samples can appear gray. It is slightly soluble in water. It consists of a benzene ring substituted with amino and carboxyl groups. The compound occurs extensively in the natural world.
Ecamsule is an organic compound which is added to many sunscreens to filter out UVA rays. It is a benzylidene camphor derivative, many of which are known for their excellent photostability.
Avobenzone is an organic molecule and an oil-soluble ingredient used in sunscreen products to absorb the full spectrum of UVA rays.
UV filters are compounds, mixtures, or materials that block or absorb ultraviolet (UV) light. One of the major applications of UV filters is their use as sunscreens to protect skin from sunburn and other sun/UV related damage. After the invention of digital cameras changed the field of photography, UV filters have been used to coat glass discs fitted to camera lenses to protect hardware that is sensitive to UV light.
Padimate O is an organic compound related to the water-soluble compound PABA that is used as an ingredient in some sunscreens. This yellowish water-insoluble oily liquid is an ester formed by the condensation of 2-ethylhexanol with dimethylaminobenzoic acid. Other names for padimate O include 2-ethylhexyl 4-dimethylaminobenzoate, Escalol 507, octyldimethyl PABA, and OD-PABA.
Octocrylene is an organic compound used as an ingredient in sunscreens and cosmetics. It is an ester formed by the Knoevenagel condensation of 2-ethylhexyl cyanoacetate with benzophenone. It is a viscous, oily liquid that is clear and colorless.
2-Ethylhexyl salicylate also known as octisalate or octyl salicylate, is an organic compound used as an ingredient in sunscreens and cosmetics to absorb UVB (ultraviolet) rays from the sun. It is an ester formed by the condensation of salicylic acid with 2-ethylhexanol. It is a colorless oily liquid with a slight floral odor.
2-Ethylhexanol is an organic compound with the chemical formula CH3CH2CH2CH2CH(CH2CH3)CH2OH. It is a branched, eight-carbon chiral alcohol. It is a colorless liquid that is poorly soluble in water but soluble in most organic solvents. It is produced on a large scale (>2,000,000,000 kg/y) for use in numerous applications such as solvents, flavors, and fragrances and especially as a precursor for production of other chemicals such as emollients and plasticizers. It is encountered in plants, fruits, and wines. The odor has been reported as "heavy, earthy, and slightly floral" for the R enantiomer and "a light, sweet floral fragrance" for the S enantiomer.
Photoprotection is the biochemical process that helps organisms cope with molecular damage caused by sunlight. Plants and other oxygenic phototrophs have developed a suite of photoprotective mechanisms to prevent photoinhibition and oxidative stress caused by excess or fluctuating light conditions. Humans and other animals have also developed photoprotective mechanisms to avoid UV photodamage to the skin, prevent DNA damage, and minimize the downstream effects of oxidative stress.
Homosalate is an organic compound used in some sunscreens. It is made by the Fischer–Speier esterification of salicylic acid and 3,3,5-trimethylcyclohexanol, the latter being a hydrogenated derivative of isophorone. Contained in 45% of U.S. sunscreens, it is used as a chemical UV filter. The salicylic acid portion of the molecule absorbs ultraviolet rays with a wavelength from 295 nm to 315 nm, protecting the skin from sun damage. The hydrophobic trimethyl cyclohexyl group provides greasiness that prevents it from dissolving in water.
Bisoctrizole is a phenolic benzotriazole that is added to sunscreens to absorb UV rays. It is a broad-spectrum ultraviolet radiation absorber, absorbing UVB as well as UVA rays. It also reflects and scatters UV.
Pyrimidine dimers represent molecular lesions originating from thymine or cytosine bases within DNA, resulting from photochemical reactions. These lesions, commonly linked to direct DNA damage, are induced by ultraviolet light (UV), particularly UVC, result in the formation of covalent bonds between adjacent nitrogenous bases along the nucleotide chain near their carbon–carbon double bonds, the photo-coupled dimers are fluorescent. Such dimerization, which can also occur in double-stranded RNA (dsRNA) involving uracil or cytosine, leads to the creation of cyclobutane pyrimidine dimers (CPDs) and 6–4 photoproducts. These pre-mutagenic lesions modify the DNA helix structure, resulting in abnormal non-canonical base pairing and, consequently, adjacent thymines or cytosines in DNA will form a cyclobutane ring when joined together and cause a distortion in the DNA. This distortion prevents DNA replication and transcription mechanisms beyond the dimerization site.
Indirect DNA damage occurs when a UV-photon is absorbed in the human skin by a chromophore that does not have the ability to convert the energy into harmless heat very quickly. Molecules that do not have this ability have a long-lived excited state. This long lifetime leads to a high probability for reactions with other molecules—so-called bimolecular reactions. Melanin and DNA have extremely short excited state lifetimes in the range of a few femtoseconds (10−15s). The excited state lifetime of compounds used in sunscreens such as menthyl anthranilate, avobenzone or padimate O is 1,000 to 1,000,000 times longer than that of melanin, and therefore they may cause damage to living cells that come in contact with them.
Amiloxate is an organic molecule used as UV filter in sunscreen products. It is approved for use in the European Union and is undergoing regulatory evaluation in the United States.
2-Ethylhexyl acrylate is a colorless liquid acrylate used in the making of paints, plastics and adhesives. It has an odor that has been variously described as pleasant or acrid and musty.
The Public Access to Sunscreens Coalition, or PASS Coalition, is a coalition of public health organizations, dermatologists and sunscreen product companies whose mission is to help prevent skin cancer and improve public health by ensuring Americans have access to safe and effective sunscreens and evidence-based education on sun-safe practices. It accomplishes these goals by lobbying for an efficient and transparent regulatory pathway to market for new sunscreens and advocating against proposals that limit access to FDA-approved sunscreens.
A Certified Organic Sunscreen, also known as Petrochemical-Free Sunscreen, is a third party certified sunscreen product consisting of certified and approved organic ingredients, with typically zinc oxide acting as the photo-protector. An organic sunscreen is verified and approved by a certifier to international or national organic standards, such as NSF/ANSI 305 and USDA organic, which define production and labelling requirements for personal care products containing organic ingredients. These standards are complemented by existing sunscreen regulatory bodies such as the FDA that regulate the efficacy of the sunscreen, safety and permitted ingredients. Generally speaking, sunscreen has photo-protective properties that reduce the risk of skin cancer and ageing with relation to the SPF value and proper application.