D'Alexandri Fabio Luiz, Tonhosolo Renata, Kimura Emilia A, Katzin Alejandro Miguel
Department of Medical Biochemistry and Biophysics, Division of Physiological Chemistry II, Karolinska Institutet, Stockholm, Sweden.
Methods Mol Biol. 2009;580:109-28. doi: 10.1007/978-1-60761-325-1_6.
Direct analysis of polyisoprenoid alcohols by electrospray ionization mass spectrometry (ESI-MS) often produces poor results requiring off-line time- and sample-consuming derivatization techniques. In this chapter, we describe a simple ESI-MS approach for the direct analysis of polyisoprenoid alcohols from biological samples. Lithium iodide is used to promote cationization by intense formation of M+Li adducts. Detection of polyisoprenoids with mass determination can thus be performed with high sensitivity (LOD near 100 pM), whereas characteristic collision-induced dissociations observed for both dolichols and polyprenols permit investigation of their structure. We also describe a simple ESI-MS approach for the direct analysis of carotenoids in biological samples using lithium iodide to promote their ionization and the analysis of several carotenoids as proof-of-principle cases. Finally, we applied ESI(Li(+))-MS and ESI(Li(+))-MS/MS to investigate the presence of carotenoids in Plasmodium falciparum.
通过电喷雾电离质谱法（ESI-MS）直接分析多聚异戊二烯醇往往会得到较差的结果，这需要采用离线的、耗费时间和样品的衍生化技术。在本章中，我们描述了一种用于直接分析生物样品中多聚异戊二烯醇的简单ESI-MS方法。碘化锂用于通过强烈形成M+Li加合物来促进阳离子化。因此，通过质量测定对多聚异戊二烯类化合物的检测可以高灵敏度地进行（检测限接近100 pM），而观察到的对于多萜醇和多聚戊烯醇的特征性碰撞诱导解离允许对其结构进行研究。我们还描述了一种用于直接分析生物样品中类胡萝卜素的简单ESI-MS方法，该方法使用碘化锂促进其电离，并以几种类胡萝卜素作为原理验证案例进行分析。最后，我们应用ESI(Li(+))-MS和ESI(Li(+))-MS/MS来研究恶性疟原虫中类胡萝卜素的存在情况。
