- Padimate O
IUPACName=4-dimethylaminobenzoic acid 2-ethylhexyl ester
OtherNames=2-ethylhexl dimethyl PABA
Section1= Chembox Identifiers
Section2= Chembox Properties
Section3= Chembox Hazards
Padimate O is an
organic compoundthat is an ingredient in some sunscreens. It is a derivative of PABA, an esterformed by the condensation of 2-ethylhexanol and dimethylaminobenzoic acid. It is a yellowish oily liquid that is insoluble in water. It absorbs ultravioletrays, thereby preventing direct DNA damageby UV-B. Unfortunately the excited padimate O molecule reacts bimolecularly with DNA and produces indirect DNA damages, that are similar to those done by ionizing radiation. Therefore padimate o is presumably photocarcinogenic.cite journal| author=Melanie Gulston, John Knowland| coauthors=S. H. Moss, D. J. Davies| title=Illumination of human keratinocytes in the presence of sunscreen ingredient padimat-O .... increases strand breaks.| journal=Mutation Research| volume=1999| issue=444| pages=49–60| year=1999]
Other names for padimate-O are: 2-ethylhexyl 4-dimethylaminobenzoate, Escalol 507, oxtyldimethyl PABA, or OD-PABA.
This compound does not dissipate energy as fast as
melanin, and therefore it is unsuitable as a sunscreen ingredient (see photoprotection).
The photobiological properties of padimate O resemble that of
Michler's ketone. The compound has been shown to increase the lethal effects of UV-radiation.cite journal |author=Knowland, John; McKenzie, Edward A.; McHugh, Peter J.; Cridland, Nigel A. |title= Sunlight-induced mutagenicity of a common sunscreen ingredient. | journal= FEBS Letters |volume= 324(3) |pages=309–313 |year=1993 |doi= 10.1016/0014-5793(93)80141-G ] Michler's ketone is known to be photocarcinogenic in rats and mice, therefore padimate O is implicated in the sunscreen controversy.
Padimate A, a related sunscreen ingredient
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