Johannes Christian, Lorenz Reinhard L
Institute for Prophylaxis of Cardiovascular Diseases, University of Munich, Pettenkofer Str. 9, 80336 Munich, Germany.
Anal Biochem. 2004 Feb 1;325(1):107-16. doi: 10.1016/j.ab.2003.10.008.
To lower cholesterol, phytosterols are currently introduced as food additives, where they may become oxidized. In addition, specific biological effects of oxyphytosterols are suggested by the recent molecular clarification of the phytosterol storage disease as a dysfunctional mutation of an active sterol reexporter potentially regulated by oxidized phytosterols. We therefore studied the hydroxybenzotriazole-mediated PbO(2)-driven oxidation of phytosterols and compared it to the oxidation of cholesterol. We prepared, identified, and purified standards of 14 oxidation products of two major phytosterols. The gas chromatographic mass spectrometric characteristics of the 7alpha- and 7beta-hydroxy-, 5alpha,6alpha-epoxy, 5beta,6beta-epoxy, 7keto-, 3beta,5alpha,6beta-trihydroxy-, 3keto-, and 7-dehydro-derivatives of beta-sitosterol and stigmasterol are presented. The method also provided a convenient access to prepare 18O-labeled oxyphytosterols of high chemical and isotopic purity and can easily be extended to further phytosterols and -stanols. This enables the gas chromatography-mass spectrometry analysis of oxyphytosterols and the study of their biological effects.
为了降低胆固醇，目前将植物甾醇作为食品添加剂引入，在此过程中它们可能会被氧化。此外，最近对植物甾醇储存疾病的分子阐释表明氧化植物甾醇具有特定的生物学效应，该疾病是一种活性甾醇再输出体的功能失调性突变，可能受氧化植物甾醇调控。因此，我们研究了羟基苯并三唑介导的PbO₂驱动的植物甾醇氧化，并将其与胆固醇的氧化进行比较。我们制备、鉴定并纯化了两种主要植物甾醇的14种氧化产物的标准品。给出了β-谷甾醇和豆甾醇的7α-和7β-羟基、5α,6α-环氧、5β,6β-环氧、7-酮、3β,5α,6β-三羟基、3-酮和7-脱氢衍生物的气相色谱-质谱特征。该方法还为制备高化学纯度和同位素纯度的¹⁸O标记氧化植物甾醇提供了便利途径，并且可以轻松扩展到其他植物甾醇和植物甾烷醇。这使得能够对氧化植物甾醇进行气相色谱-质谱分析并研究其生物学效应。
