Abstract：
Oxysterols and cholesterol precursors are being increasingly investigated in humans and laboratory animals as markers for various diseases in addition to their important functions. However, the quantitative analysis of these bioactive molecules is obstructed by high structural similarity, poor ionization efficiency and low abundance. The current assay methods are still cumbersome to be of practical use, and their applicability in different bio-samples needs to be evaluated and optimized as necessary. In the present work, chromatographic separation conditions were carefully studied to achieve baseline separation of difficult-to-isolate compound pairs. On the other hand, an efficient sample purification method was established for colon tissue samples with good recoveries of sterols, demonstrating negligible autoxidation of cholesterol into oxysterols. The developed UPLC-APCI-MS/MS method was thoroughly validated and applied to measure oxysterols and cholesterol precursors in colon tissue of dextran sulfate sodium (DSS)-induced mouse colitis models, and it is expected to be successfully applied to the quantitative determination of such components in other tissue samples.
摘要：
在人和实验动物中越来越多地研究氧化甾醇和胆固醇前体作为各种疾病的标记物以及它们的重要功能。然而,这些生物活性分子的定量分析受到高度结构相似性的阻碍，电离效率低，丰度低。目前的测定方法仍然是繁琐的实际使用，它们在不同生物样品中的适用性需要根据需要进行评估和优化。在目前的工作中,仔细研究了色谱分离条件，以实现难以分离的化合物对的基线分离。另一方面,建立了一种高效的结肠组织样品纯化方法，具有良好的甾醇回收率，证明胆固醇自动氧化为氧固醇可以忽略不计。已开发的UPLC-APCI-MS/MS方法经过全面验证，并用于测定葡聚糖硫酸钠（DSS）诱导的小鼠结肠炎模型的结肠组织中的氧固醇和胆固醇前体，有望成功应用于其他组织样品中此类成分的定量测定。
