Padimate O

Last updated
Padimate O
Padimate O.png
Names
IUPAC name
2-ethylhexyl 4-(dimethylamino)benzoate
Other names
2-ethylhexyl dimethyl PABA
Escalol 507
Sundown
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.040.248
KEGG
PubChem CID
UNII
Properties
C17H27NO2
Molar mass 277.408 g·mol−1
Density 0.99 g/cm3
Melting point <25 °C
Boiling point 362 °C (684 °F; 635 K)
Hazards
NFPA 704
Flammability code 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g., canola oilHealth code 1: Exposure would cause irritation but only minor residual injury. E.g., turpentineReactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogenSpecial hazards (white): no codePadimate O
1
1
0
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Padimate O is an organic compound related to the water-soluble compound PABA (4-aminobenzoic acid) 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.

Organic compound chemical compound that contains carbon (except for a several compounds traditionally classified as inorganic compounds)

In chemistry, an organic compound is generally any chemical compound that contains carbon. Due to carbon's ability to catenate, millions of organic compounds are known. Study of the properties and synthesis of organic compounds is the discipline known as organic chemistry. For historical reasons, a few classes of carbon-containing compounds, along with a handful of other exceptions, are not classified as organic compounds and are considered inorganic. No consensus exists among chemists on precisely which carbon-containing compounds are excluded, making the definition of an organic compound elusive.

4-Aminobenzoic acid (also known as para-aminobenzoic acid or PABA because the number 4 carbon in the benzene ring is also known as 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.

Sunscreen topical skin product that helps protect against sunburn

Sunscreen, also known as sunblock, sun cream or suntan lotion, is a lotion, spray, gel, foam, stick or other topical product that absorbs or reflects some of the sun's ultraviolet (UV) radiation and thus helps protect against sunburn. Diligent use of sunscreen can also slow or temporarily prevent the development of wrinkles, moles and sagging skin.

Contents

Photobiology

Padimate O absorbs ultraviolet rays, thereby preventing direct DNA damage by UV-B. However, the thus-excited padimate O molecule may then react with DNA to produce indirect DNA damage, similar to the effects of ionizing radiation. An in vitro yeast study conducted in 1993 demonstrated the sunlight-induced mutagenicity of padimate O. [1] The photobiological properties of padimate O resemble those of Michler's ketone, which is considered photocarcinogenic in rats and mice. These findings suggest that padimate O might also be photocarcinogenic. [2]

Ultraviolet Electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays

Ultraviolet (UV) designates a band of the electromagnetic spectrum with wavelength from 10 nm to 400 nm, shorter than that of visible light but longer than X-rays. UV radiation is present in sunlight, and contributes about 10% of the total light output of the Sun. It is also produced by electric arcs and specialized lights, such as mercury-vapor lamps, tanning lamps, and black lights. Although long-wavelength ultraviolet is not considered an ionizing radiation because its photons lack the energy to ionize atoms, it can cause chemical reactions and causes many substances to glow or fluoresce. Consequently, the chemical and biological effects of UV are greater than simple heating effects, and many practical applications of UV radiation derive from its interactions with organic molecules.

Direct DNA damage

Direct DNA damage can occur when DNA directly absorbs a UVB photon, or for numerous other reasons. UVB light causes thymine base pairs next to each other in genetic sequences to bond together into pyrimidine dimers, a disruption in the strand, which reproductive enzymes cannot copy. It causes sunburn and it triggers the production of melanin.

Indirect DNA damage caused by UV-photons

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 these substances is 1,000 to 1,000,000 times longer than the lifetime of melanin, and therefore they may cause damage to living cells that come in contact with them.

However, multiple in vivo studies conducted in hairless mice following topical application of padimate O have demonstrated no carcinogenic effects and that padimate O reduces the number of and delays the appearance of UV-induced skin tumors. [3] [4] [5] [6]

Studies that are in vivo are those in which the effects of various biological entities are tested on whole, living organisms or cells, usually animals, including humans, and plants, as opposed to a tissue extract or dead organism. This is not to be confused with experiments done in vitro, i.e., in a laboratory environment using test tubes, Petri dishes, etc. Examples of investigations in vivo include: the pathogenesis of disease by comparing the effects of bacterial infection with the effects of purified bacterial toxins; the development of non-antibiotics, antiviral drugs, and new drugs generally; and new surgical procedures. Consequently, animal testing and clinical trials are major elements of in vivo research. In vivo testing is often employed over in vitro because it is better suited for observing the overall effects of an experiment on a living subject. In drug discovery, for example, verification of efficacy in vivo is crucial, because in vitro assays can sometimes yield misleading results with drug candidate molecules that are irrelevant in vivo.

See also

Padimate A chemical compound

Padimate A is an organic compound that is an ingredient in some sunscreens. It is an ester derivative of PABA. This aromatic chemical absorbs ultraviolet rays thereby preventing sunburn. However, its chemical structure and behaviour is similar to an industrial free radical generator. In Europe this chemical was withdrawn in 1989 for unstated reasons. In the US it was never approved for use in sunscreens.

Related Research Articles

Sun tanning the darkening of skin in response to ultraviolet light

Sun tanning or simply tanning is the process whereby skin color is darkened or tanned. It is most often a result of exposure to ultraviolet (UV) radiation from sunlight or from artificial sources, such as a tanning lamp found in indoor tanning beds. People who deliberately tan their skin by exposure to the sun engage in a passive recreational activity of sun bathing. Some people use chemical products which can produce a tanning effect without exposure to ultraviolet radiation, known as sunless tanning.

Actinic keratosis Human disease

Actinic keratosis (AK) is a pre-cancerous area of thick, scaly, or crusty skin. These growths are more common in fair-skinned people and those who are frequently in the sun. They are believed to form when skin gets damaged by ultraviolet (UV) radiation from the sun or indoor tanning beds, usually over the course of decades. Given their pre-cancerous nature, if left untreated, they may turn into a type of skin cancer called squamous cell carcinoma. Untreated lesions have up to a 20% risk of progression to squamous cell carcinoma, so treatment by a dermatologist is recommended.

Sunless tanning

Sunless tanning, also known as UV filled tanning, self tanning, spray tanning, or fake tanning, refers to the effect of a suntan without the Sun. The popularity of sunless tanning has risen since the 1960s after health authorities confirmed links between UV exposure and the incidence of skin cancer.

Ecamsule chemical compound

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 chemical compound

Avobenzone is an oil-soluble ingredient used in sunscreen products to absorb the full spectrum of UVA rays.

UV filter camera parts, features and technologies

UV filters are individual compounds or mixtures that block or absorb ultraviolet (UV) light. Two major applications of UV filters are in sunscreens, where they protect the skin from sunburn and other damage, and in photography, where they reduce the level of ultraviolet light that strikes the recording medium. When exposed to UV light, these filters can undergo transformations into other chemicals that are less protective and possibly toxic. As a result, there are practical concerns about the choice of chemical to use beyond just which has the desired filtering properties.

Octocrylene chemical compound

Octocrylene is an organic compound used as an ingredient in sunscreens and cosmetics. It is an ester formed by the reaction of 3,3-diphenylcyanoacrylate with 2-ethylhexanol. It is a viscous, oily liquid that is clear and colorless.

UVB-induced apoptosis is the programmed cell death of cells that become damaged by ultraviolet rays. This is notable in skin cells, to prevent melanoma. Some studies have shown that exercise accelerates this process.

Tanning activators are chemicals that increase the effect of UV-radiation on the human skin.

Sunburn burning of the skin by the suns radiation

Sunburn is a form of radiation burn that affects living tissue, such as skin, that results from an overexposure to ultraviolet (UV) radiation, commonly from the sun. Common symptoms in humans and other animals include red or reddish skin that is hot to the touch, pain, general fatigue, and mild dizziness. An excess of UV radiation can be life-threatening in extreme cases. Excessive UV radiation is the leading cause of primarily non-malignant skin tumors.

Photoaging or photoageing is a term used for the characteristic changes to skin induced by chronic UVA and UVB exposure. Tretinoin is the best studied retinoid in the treatment of photoaging

Health effects of sunlight exposure

The ultraviolet radiation in sunlight has both positive and negative health effects, as it is both a principal source of vitamin D3 and a mutagen. A dietary supplement can supply vitamin D without this mutagenic effect. Vitamin D has been suggested as having a wide range of positive health effects, which include strengthening bones and possibly inhibiting the growth of some cancers. UV exposure also has positive effects for endorphin levels, and possibly for protection against multiple sclerosis. Visible sunlight to the eyes gives health benefits through its association with the timing of melatonin synthesis, maintenance of normal and robust circadian rhythms, and reduced risk of seasonal affective disorder.

Exobiology Radiation Assembly experiment in Earth orbit

Exobiology Radiation Assembly (ERA) was an experiment that investigated the biological effects of space radiation, on board the European Retrievable Carrier (EURECA), an unmanned 4.5 tonne satellite with a payload of 15 experiments. It was an astrobiology mission developed by the European Space Agency (ESA).

Antimutagens are the agents that interfere with the mutagenicity of a substance. The interference can be in the form of prevention of the transformation of a mutagenic compound into mutagen, inactivation, or otherwise the prevention of Mutagen-DNA reaction.

References

  1. ↑ Knowland, John; McKenzie, Edward A; McHugh, Peter J; Cridland, Nigel A (1993). "Sunlight-induced mutagenicity of a common sunscreen ingredient". FEBS Letters. 324 (3): 309–13. doi:10.1016/0014-5793(93)80141-G. PMID   8405372.
  2. ↑ Gulston, Melanie; Knowland, John (1999). "Illumination of human keratinocytes in the presence of the sunscreen ingredient Padimate-O and through an SPF-15 sunscreen reduces direct photodamage to DNA but increases strand breaks". Mutation Research/Genetic Toxicology and Environmental Mutagenesis. 444: 49–60. doi:10.1016/S1383-5718(99)00091-1. PMID   10477339.
  3. ↑ Kligman, Lorraine H.; Akin, Frank J.; Kligman, Albert M. (1980). "Sunscreens prevent ultraviolet photocarcinogenesis". Journal of the American Academy of Dermatology. 3 (1): 30–5. doi:10.1016/S0190-9622(80)80221-0. PMID   6967495.
  4. ↑ Bissett, Donald L.; McBride, James F.; Hannon, Daniel P.; Patrick, Larry F. (1991). "Time-dependent decrease in sunscreen protection against chronic photodamage in UVB-irradiated hairless mouse skin". Journal of Photochemistry and Photobiology B: Biology. 9 (3–4): 323–334. doi:10.1016/1011-1344(91)80169-I.
  5. ↑ Bissett, Donald L; McBride, James F (1996). "Synergistic topical photoprotection by a combination of the iron chelator 2-furildioxime and sunscreen". Journal of the American Academy of Dermatology. 35 (4): 546–9. doi:10.1016/S0190-9622(96)90677-5. PMID   8859281.
  6. ↑ Kerr, Caroline (1998). "The effects of two UVB radiation-absorbing sunscreens on UV radiation-induced carcinogenesis, suppression of the contact hypersensitivity response and histological changes in the hairless mouse". Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis. 422 (1): 161–4. doi:10.1016/S0027-5107(98)00188-2. PMID   9920441.
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