Breinhölder Patrick, Mosca Livia, Lindner Wolfgang
Institute of Analytical Chemistry, University of Vienna, Währingerstrasse 38, A-1090, Vienna, Austria.
J Chromatogr B Analyt Technol Biomed Life Sci. 2002 Sep 25;777(1-2):67-82. doi: 10.1016/s1570-0232(02)00093-4.
A unique concept and method for the determination of the total plant sterol content as sum of free sterols (FS), steryl esters (SE), steryl glycosides (SG) and acylated steryl glycosides (ASG) in different plant materials (pumpkin seeds, lecithins) and phytopharmaceuticals derived thereof, was developed. For this purpose, a multidimensional sample clean-up protocol based on efficient solid-phase extraction materials was elaborated and the SG were isolated employing a novel phenyl boronic acid modified silica gel material. Along this line also a set of steryl glucosides was synthesised and employed as internal standard and for calibration in the course of quantitative analysis. Final quantification of SG was carried out with reversed-phase HPLC in combination with evaporative light scattering detection (ELSD); the ASG were determined after conversion to SG by mild alkaline hydrolysis. In order to determine the total plant sterol profile the sum of FS and SE was additionally analysed from the unsaponifiable lipid fraction by GC-FID. The yields obtained from recovery tests for the determination of SG using soya lecithin as matrix to which 2, 20 and 40 mg/g of cholesterol-beta-D-glucoside was added were 99.10, 98.07 and 90.00%, and the RSDs were 4.11, 2.62 and 4.50%, respectively. Application related to the qualitative and quantitative analysis of total phytosterol profiles in different plant matrices and extracts demonstrate the validity of the method.
开发了一种独特的概念和方法，用于测定不同植物材料（南瓜籽、卵磷脂）及其衍生的植物药中游离甾醇（FS）、甾醇酯（SE）、甾醇糖苷（SG）和酰化甾醇糖苷（ASG）总和形式的总植物甾醇含量。为此，精心制定了基于高效固相萃取材料的多维样品净化方案，并采用新型苯基硼酸改性硅胶材料分离SG。同时还合成了一组甾醇葡萄糖苷用作内标，并在定量分析过程中用于校准。SG的最终定量采用反相高效液相色谱结合蒸发光散射检测（ELSD）进行；ASG通过温和碱性水解转化为SG后进行测定。为了测定总植物甾醇谱，还从未皂化脂质部分通过气相色谱-火焰离子化检测（GC-FID）分析FS和SE的总和。以大豆卵磷脂为基质，分别添加2、20和40 mg/g胆固醇-β-D-葡萄糖苷进行SG测定的回收率试验，所得回收率分别为99.10%、98.07%和90.00%，相对标准偏差分别为4.11%、2.62%和4.50%。该方法在不同植物基质和提取物中总植物甾醇谱的定性和定量分析中的应用证明了其有效性。
