Sattler W, Puhl H, Hayn M, Kostner G M, Esterbauer H
Institute of Biochemistry, University of Graz, Austria.
Anal Biochem. 1991 Oct;198(1):184-90. doi: 10.1016/0003-2697(91)90526-y.
The amount of individual fatty acids contained in the main human lipoproteins VLDL, LDL, lipoprotein (a), HDL2, and HDL3 were determined by two different methods. In Method I, the lipids were first extracted by the classical Folch procedure and then transesterified with BF3/methanol and separated by capillary GC. In Method II the lipoprotein solution was freeze dried prior to transesterification with BF3/methanol. In all lipoproteins except VLDL significantly more fatty acids were found with Method II as compared to Method I. For total fatty acids the increase was up to 17.5%, for polyunsaturated fatty acids up to 24.5%. The total fatty acid content determined by Method II resembled closely the content independently derived from the enzymatically determined lipid composition. The results indicate that in case of lipoproteins quantification of fatty acids should be made with freeze-dried samples rather than with Folch extracts.
采用两种不同方法测定了人类主要脂蛋白极低密度脂蛋白（VLDL）、低密度脂蛋白（LDL）、脂蛋白（a）、高密度脂蛋白2（HDL2）和高密度脂蛋白3（HDL3）中所含的各种脂肪酸含量。方法I中，首先采用经典的Folch法提取脂质，然后用三氟化硼/甲醇进行酯交换反应，并用毛细管气相色谱法进行分离。方法II中，脂蛋白溶液在与三氟化硼/甲醇进行酯交换反应之前先进行冷冻干燥。与方法I相比，除VLDL外的所有脂蛋白中，方法II检测到的脂肪酸明显更多。总脂肪酸增加高达17.5%，多不饱和脂肪酸增加高达24.5%。方法II测定的总脂肪酸含量与通过酶法测定脂质组成独立得出的含量非常接近。结果表明，对于脂蛋白，脂肪酸定量应采用冷冻干燥样品而非Folch提取物。
