Liebler D C, Matsumoto S, Iitaka Y, Matsuo M
Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson 85721.
Chem Res Toxicol. 1993 Jan-Feb;6(1):69-74. doi: 10.1021/tx00031a011.
Reaction of vitamin E [(R,R,R)-alpha-tocopherol] with ozone in acetonitrile yielded alpha-tocopheryl quinone and its precursor 8a-hydroxytocopherone, which accounted for approximately 30% of the products at < 50% alpha-tocopherol oxidation. In addition, two novel products were identified as epimers of 10-acetyl-7-(4',8',12'-trimethyltridecyl)-3,4,7-trimethyl-2-oxo- 1,6-dioxaspiro[4.5]-deca-3,9-diene. These spiro products were formed in equal amounts in a combined yield of approximately 33% after complete alpha-tocopherol oxidation. Ozonation of the vitamin E model compound 2,2,5,7,8-pentamethylchroman-6-ol yielded an analogous spiro product, 10-acetyl-3,4,7,7-tetramethyl-2-oxo-1,6-dioxaspiro[4.5]deca-3,9-di ene, whose structure was confirmed by X-ray crystallography. The spiro products may be formed by ozone addition to the chroman ring and subsequent rearrangement to ring-opened hydroxyacid products, which yield spiro products by ring closure due to dehydration. Novel spiro products formed by ozonation of vitamin E may be unique markers of ozone interaction with lipid structures that contain vitamin E.
维生素E[（R，R，R）-α-生育酚]与臭氧在乙腈中反应生成α-生育酚醌及其前体8a-羟基生育酚酮，在α-生育酚氧化率<50%时，它们约占产物的30%。此外，还鉴定出两种新产物，它们是10-乙酰基-7-（4'，8'，12'-三甲基十三烷基）-3，4，7-三甲基-2-氧代-1，6-二氧杂螺[4.5]-癸-3，9-二烯的差向异构体。在α-生育酚完全氧化后，这些螺环产物以等量生成，总产率约为33%。维生素E模型化合物2，2，5，7，8-五甲基苯并二氢吡喃-6-醇的臭氧化反应生成了一种类似的螺环产物，即10-乙酰基-3，4，7，7-四甲基-2-氧代-1，6-二氧杂螺[4.5]癸-3，9-二烯，其结构通过X射线晶体学得到证实。螺环产物可能是由臭氧加成到苯并二氢吡喃环上，随后重排为开环羟基酸产物，该产物由于脱水闭环而生成螺环产物。维生素E臭氧化形成的新型螺环产物可能是臭氧与含有维生素E的脂质结构相互作用的独特标志物。
