Sköld Maria, Hagvall Lina, Karlberg Ann-Therese
Department of Chemistry, Dermatochemistry and Skin Allergy, Göteborg University, SE-412 96 Göteborg, Sweden.
Contact Dermatitis. 2008 Jan;58(1):9-14. doi: 10.1111/j.1600-0536.2007.01262.x.
Fragrances are among the most common causes of allergic contact dermatitis. We have in previous studies shown that linalool, present in lavender oil, autoxidizes on air exposure, forming allergenic oxidation products. Oxidized linalool was found to be a frequent cause of contact allergy in a patch test study on consecutive dermatitis patients. Linalyl acetate, the main component of lavender oil is commonly used as a fragrance chemical in scented products. Because of structural similarities, linalyl acetate should also be susceptible to oxidation on air exposure, forming similar oxidation products as linalool.
The aim of the present study was to investigate the autoxidation of linalyl acetate and the influence of oxidation on its sensitizing potency.
Analyses were performed using gas chromatography, nuclear magnetic resonance spectrometry and mass spectrometry. Sensitizing potencies of compounds were determined using the local lymph node assay (LLNA) in mice.
Analyses showed that the content of linalyl acetate decreased over time on air exposure and other compounds were formed. Hydroperoxides, an epoxide and an alcohol were identified as oxidation products from linalyl acetate. In the LLNA, linalyl acetate of high purity showed a weak sensitizing potency (EC3 25%). Autoxidation increased the sensitizing potency of linalyl acetate, and a 10 weeks oxidized sample gave an EC3 value of 3.6%. As for linalool, the hydroperoxides were shown to be the oxidation products with the highest sensitizing potency.
It is concluded that autoxidation of the weakly allergenic linalyl acetate leads to formation of allergenic oxidation products.
香料是过敏性接触性皮炎最常见的病因之一。我们在之前的研究中表明，薰衣草油中的芳樟醇在暴露于空气中时会自动氧化，形成致敏性氧化产物。在一项针对连续性皮炎患者的斑贴试验研究中，发现氧化芳樟醇是接触性过敏的常见原因。乙酸芳樟酯是薰衣草油的主要成分，常用于香薰产品中的香料化学品。由于结构相似，乙酸芳樟酯在暴露于空气中时也应易于氧化，形成与芳樟醇相似的氧化产物。
本研究的目的是研究乙酸芳樟酯的自动氧化及其氧化对致敏能力的影响。
使用气相色谱、核磁共振光谱和质谱进行分析。使用小鼠局部淋巴结试验（LLNA）测定化合物的致敏能力。
分析表明，乙酸芳樟酯在暴露于空气中时含量随时间下降，并形成了其他化合物。氢过氧化物、一种环氧化物和一种醇被鉴定为乙酸芳樟酯的氧化产物。在LLNA中，高纯度的乙酸芳樟酯显示出较弱的致敏能力（EC3 25%）。自动氧化增加了乙酸芳樟酯的致敏能力，一个氧化10周的样品的EC3值为3.6%。至于芳樟醇，氢过氧化物被证明是致敏能力最高的氧化产物。
得出的结论是，弱致敏性的乙酸芳樟酯自动氧化会导致形成致敏性氧化产物。
