Ichihara Ken'ichi, Yamaguchi Chiaki, Araya Yumiko, Sakamoto Asami, Yoneda Kumiko
Department of Biological Chemistry, Graduate School of Agricultural Science, Kyoto Prefectural University, Shimogamo, Kyoto 606-8522, Japan.
Lipids. 2010 Apr;45(4):367-74. doi: 10.1007/s11745-010-3404-5. Epub 2010 Mar 21.
KOH in aqueous methanol catalyzes selective methanolysis of polar glycerolipids with O-ester-linked acyl residues, while triacylglycerols and sterol esters are inert in the solution. Based on these findings, a convenient and reliable method was developed for the preparation of fatty acid methyl esters (FAMEs) from polar glycerolipids in lipid mixtures without prior isolation. Methanolysis of polar glycerolipids was completed within 2.5 min by vortexing or 20 min by shaking with 0.7 M KOH/70% (v/v) methanol in the presence of hexane at 30 degrees C. The yields of FAMEs obtained by the present method were greater than 95%. The method was applied successfully to gas chromatographic analysis of the fatty acid compositions of polar glycerolipids in seed oil and blood. No obvious differences were found between the fatty acid compositions determined by the present method and those determined by conventional methods, including lipid extraction with chloroform/methanol followed by isolation of polar lipids by chromatography. The fatty acid composition of polar glycerolipids, including phospholipids, can be determined readily in many crude samples.
甲醇中的氢氧化钾催化具有O-酯键连接酰基残基的极性甘油脂质的选择性甲醇解，而三酰基甘油和甾醇酯在该溶液中呈惰性。基于这些发现，开发了一种便捷可靠的方法，可在不预先分离的情况下从脂质混合物中的极性甘油脂质制备脂肪酸甲酯（FAMEs）。在30℃下，在己烷存在下，通过涡旋，极性甘油脂质的甲醇解在2.5分钟内完成，或通过与0.7M氢氧化钾/70%（v/v）甲醇振荡在20分钟内完成。通过本方法获得的脂肪酸甲酯的产率大于95%。该方法成功应用于种子油和血液中极性甘油脂质脂肪酸组成的气相色谱分析。通过本方法测定的脂肪酸组成与通过常规方法（包括用氯仿/甲醇提取脂质，然后通过色谱法分离极性脂质）测定的脂肪酸组成之间未发现明显差异。包括磷脂在内的极性甘油脂质的脂肪酸组成可以在许多粗样品中轻松测定。
