立本特異的 方法과 ₁₃C-NMR 技法에 의한 잣기름의 트리아실 글리세롤의 構成脂肪酸의 分布에 관한 硏究

Studies on the Fatty Acid Distribution in the Position of Triacylglycerols from the Seed of Pinus Koraiensis by Stereo-specific Analysis and ₁₃C-NMR Techniques

All the triacylglycerols including the molecular species having △^5-unsaturated fatty acids from the seeds of Pinus Koraiensis, were split into a mixture of diacylglycerols by a Grignard reagent prepared with allyl bromide without arousing acyl chains of a glycerol moiety to migration, and were also easily partially hydrolyzed to diacylglycerols by pancreatic lipase. (S)-(+)-(1-naphthyl)ethyl urethane(NEU) derivatives of the diacylglycerol mixture derived from the triacylglycerols were fractionated into sn-1, 3-, sn-1, 2- and sn-2, 3-DG-NEU by silica-HPLC and the fatty acid composition of these fractions was analysed. C_18:1ω9 is distributed evenly in the three positions of TG with C_18:2ω6 mainly located in sn-2 position, while △^5-unsaturated fatty acids such as △^5.9-C_18:2, △^5.9.12-C^18:3 and △^5.11.14-C_20:3 are exclusively present in the sn-3 position. These results could be confirmed by ^13C-NMR sepctroscopy : the signals at δ173.231 ppm and δ172.811 ppm of the carbonyl carbon of acyl moieties indicate the presence of saturated acids and/or C_18:1ω9 (oleic acid) in the α(α`)-or β- positions, and C_18:2ω6 including C_18:1:ω9 in the β-position, respectively. In addition, the resonance at δ173.044 ppm suggested a location of △^5-unsaturated fatty acid moiety in the α(α )-position.