Nicolaides N, Santos E C
Lipids. 1985 Jul;20(7):454-67. doi: 10.1007/BF02534237.
Three groups of diesters have been isolated and identified in the lipids of steer meibomian glands. The first group, designated as alpha Type I, with the abbreviated formula FA-alpha OHFA-FAlc, consisted of alpha-hydroxy fatty acids esterified to fatty acids and fatty alcohols in the approximate molar ratio 1:1:1. The second group, designated as omega Type I-St, with the abbreviated formula FA-omega OHFA-St, consisted of omega-hydroxy fatty acids esterified to fatty acids and sterols in the approximate molar ratio 1:1:1. The third group, designated as alpha, omega Type II, with the abbreviated formula FA-alpha, omega diol-FA, consisted of alpha, omega-diols esterified to 2 moles of fatty acids. The sum of the different diesters comprised about 9% of total steer meibomian lipids. Capillary GLC of the fatty acids of alpha Type I diesters showed the fatty acids to be a family with a two-cluster profile, one at C12 to C20 and the other at C21 to C31, with anteiso chains predominating. Fatty acids from omega Type I-St and alpha, omega Type II diesters gave mainly a one-cluster profile in the short chain region with prominent anteiso and C18:1 peaks. Fatty alcohols of alpha Type I diesters were mainly long chain, C23 to C30, with anteiso chains predominating, while the alpha-hydroxy fatty acids were short chain C13 to C18 acids with C16 predominating. The sterols in diesters omega Type I-St were cholesterol (approximately 60%), delta 7 cholestenol (approximately 35%) and an unidentified compound (approximately 5%) with a GLC retention time slightly longer than delta 7 cholestenol on SE-30 phase. The omega-hydroxy fatty acids and alpha, omega-diols both were of exceedingly long chain lengths, C29-C38, and showed similar GLC profiles. Two types of triesters comprising approximately 1% of total steer meibomian lipids have been isolated but incompletely characterized. In terms of molar ratios, one group of triesters gave fatty acids:omega-hydroxy fatty acids:alpha-hydroxy fatty acids:sterols + fatty alcohols as approximately 1:1:1:1. The other contained fatty acids, alpha-hydroxy fatty acids and alpha, omega-diols in what appears to be a complex mixture of several triesters. Diesters omega Type I and alpha, omega Type II also were found in human meibum. Hitherto these two diesters have not been found in any animal tissue.
在牛睑板腺脂质中已分离并鉴定出三类二酯。第一类，指定为α型I，缩写式为FA-αOHFA-FAlc，由α-羟基脂肪酸与脂肪酸和脂肪醇以近似1:1:1的摩尔比酯化而成。第二类，指定为ω型I-St，缩写式为FA-ωOHFA-St，由ω-羟基脂肪酸与脂肪酸和甾醇以近似1:1:1的摩尔比酯化而成。第三类，指定为α,ω型II，缩写式为FA-α,ω二醇-FA，由α,ω-二醇与2摩尔脂肪酸酯化而成。不同二酯的总和约占牛睑板腺脂质总量的9%。α型I二酯脂肪酸的毛细管气相色谱分析表明，脂肪酸是一个具有双簇分布的家族，一簇在C12至C20，另一簇在C21至C31，以反异链为主。ω型I-St和α,ω型II二酯的脂肪酸在短链区域主要呈现单簇分布，有突出的反异链和C18:1峰。α型I二酯的脂肪醇主要是长链的，C23至C30，以反异链为主，而α-羟基脂肪酸是短链的C13至C18酸，以C16为主。ω型I-St二酯中的甾醇是胆固醇（约60%）、δ7胆甾烯醇（约35%）和一种未鉴定的化合物（约5%），其在SE-30相上的气相色谱保留时间略长于δ7胆甾烯醇。ω-羟基脂肪酸和α,ω-二醇的链长都极长，C29 - C38，并显示出相似的气相色谱图谱。已分离出两类约占牛睑板腺脂质总量1%的三酯，但表征不完全。就摩尔比而言，一类三酯的脂肪酸:ω-羟基脂肪酸:α-羟基脂肪酸:甾醇 + 脂肪醇约为1:1:1:1。另一类含有脂肪酸、α-羟基脂肪酸和α,ω-二醇，似乎是几种三酯的复杂混合物。ω型I和α,ω型II二酯也在人睑脂中被发现。迄今为止，这两种二酯尚未在任何动物组织中被发现。
