Evaluation and Quantitation of Intact Wax Esters of Human Meibum by Gas-Liquid Chromatography-Ion Trap Mass Spectrometry
Evaluation and Quantitation of Intact Wax Esters of Human Meibum by Gas-Liquid Chromatography-Ion Trap Mass Spectrometry
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DOI：
10.1167/iovs.11-9333
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发表时间：
2012-06-01
影响因子：
4.4
通讯作者：
Molai, Mike
中科院分区：
文献类型：
--
作者：
Butovich, Igor A.;Arciniega, Juan C.;Molai, Mike
目的。人梅布姆的蜡酯（我们）是最大的Meibomian脂质群之一。它们在单个完整脂质物种水平上的完整表征尚未完成。我们获得了有关先前未表征的Meibomian We.Methods的详细结构信息。完整的我们通过高温毛细管气化色谱法（GLC）与低压（30 eV）电子离子离子陷阱质谱法（ITM）结合使用，对我们进行了分离和分析。 3D（质量到电荷比[m/z]与脂质样品重量与信号强度）的校准图用于定量We.Results。我们证明了GLC-ITM适用于分析我们从14个单个捐助者那里收集的未冷却/未成熟化的。检测到超过100个饱和和不饱和的我们（分别是SWE和UWE）。平均而言，UWE约占我们总池的82％。大约90％的UWE基于油酸，而少于10％的UWE基于棕榈酸。 poly-uwe的量<占其单一元素的3％。 SWE主要基于C-16-C-18脂肪酸（FA），总摩尔比为22:65:13。 C-16：0-FA的池由直链和异形异构体的20:80（mol/mol）混合物组成，而C-18：0-FA的相应比率为43:57。有趣的是，C-17：0-FA几乎完全分支了，而与93：7的比率发现了前和异构体。 GLC-ITM可以成功地用于分析100多种Meibomian We，它们被证明构成了41 +/- 8％（wt/wt）的Meibum，这使它们成为Meibum中最大的脂质群。 （投资Ophthalmol VisSci。2012; 53：3766-3781）doi：10.1167/iovs.11-9333
PURPOSE. Wax esters (WE) of human meibum are one of the largest group of meibomian lipids. Their complete characterization on the level of individual intact lipid species has not been completed yet. We obtained detailed structural information on previously uncharacterized meibomian WE.METHODS. Intact WE were separated and analyzed by means of high-temperature capillary gas-liquid chromatography (GLC) in combination with low voltage (30 eV) electron ionization ion trap mass spectrometry (ITMS). 3D (mass-to-charge ratio [m/z] versus lipid sample weight versus signal intensity) calibration plots were used for quantitation of WE.RESULTS. We demonstrated that GLC-ITMS was suitable for analyzing unpooled/underivatized WE collected from 14 individual donors. More than 100 of saturated and unsaturated WE (SWE and UWE, respectively) were detected. On average, UWE represented about 82% of the total WE pool. About 90% of UWE were based on oleic acid, while less than 10% were based on palmitoleic acid. The amounts of poly-UWE were < 3% of their mono-UWA counterparts. SWE were based primarily on C-16-C-18 fatty acids (FA) in overall molar ratios of 22:65:13. A pool of C-16:0-FA was comprised of a 20:80 (mol/mol) mixture of straight chain and iso-branched isomers, while the corresponding ratio for C-18:0-FA was 43:57. Interestingly, C-17:0-FA was almost exclusively branched, with anteiso- and isoisomers found in a ratio of 93:7.CONCLUSIONS. GLC-ITMS can be used successfully to analyze more than 100 individual species of meibomian WE, which were shown to comprise 41 +/- 8% (wt/wt) of meibum, which made them the largest group of lipids in meibum. (Invest Ophthalmol Vis Sci. 2012;53:3766-3781) DOI:10.1167/iovs.11-9333