Padimate O
Padimate O | |
---|---|
File:Padimate O.png | |
2-ethylhexyl 4-(dimethylamino)benzoate | |
Other names 2-ethylhexyl dimethyl PABA Escalol 507 Sundown | |
style="background: #F8EABA; text-align: center;" colspan="2" | Identifiers | |
CAS number | 21245-02-3 |
PubChem | 30541 |
SMILES | Script error: No such module "collapsible list". |
style="background: #F8EABA; text-align: center;" colspan="2" | Properties | |
Molecular formula | C17H27NO2 |
Molar mass | 277.4 g mol−1 |
Density | 0.99 g/cm³ |
Melting point |
<25 °C |
Boiling point |
362 °C, 635 K, 684 °F |
(what is this?) (verify) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) | |
Infobox references |
Padimate O is an organic compound related to the water soluble compound PABA (4-aminobenzoic acid) that 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.
Photobiology
Padimate O has been implicated in the sunscreen controversy. 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]
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]
See also
- Padimate A, a related sunscreen ingredient
References
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- ↑ Knowland, John; McKenzie, Edward A.; McHugh, Peter J.; Cridland, Nigel A. (1993). "Sunlight-induced mutagenicity of a common sunscreen ingredient" (PDF). FEBS Letters. 324(3): 309–313. doi:10.1016/0014-5793(93)80141-G.
- ↑ Lua error in package.lua at line 80: module 'Module:Citation/CS1/Suggestions' not found.
- ↑ Kligman LH, Akin FJ, Kligman AM (1980). "Sunscreens prevent ultraviolet photocarcinogenesis". J Am Acad Dermatol. 3 (1): 30–35. doi:10.1016/S0190-9622(80)80221-0. PMID 6967495.
- ↑ Bissett DL, McBride JF, Hannon DP; et al. (1991). "Time-dependent decrease in sunscreen protection against chronic photodamage in UVB-irradiated hairless mouse skin". J Photochem Photobiol B. 9 (3-4): 323–334. doi:10.1016/1011-1344(91)80169-I. PMID 1919875.
- ↑ Bissett DL, McBride JF (1996). "Synergistic topical photoprotection by a combination of the iron chelator 2-furildioxime and sunscreen". J Am Acad Dermatol. 35 (4): 546–549. doi:10.1016/S0190-9622(96)90677-5. PMID 8859281.
- ↑ Kerr C (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". Mutat Res. 422 (1): 161–164. PMID 9920441.