共查询到20条相似文献,搜索用时 218 毫秒
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冻干保护剂海藻糖对磷脂脂双层有保护作用,它可以降低磷脂主相变温度,抑制膜脂侧相分离和膜融合。本实验以蛋黄卵磷脂(EPC)为模型,通过相变发生时磷脂吸热量的变化,以及磷脂脂肪酸链CH2基团的对称伸展振动频率的变化,研究海藻糖对蛋黄卵磷脂(EPC)脂质膜相变时影响,并通过FTIR红外光谱分析得到进一步验证。 相似文献
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利用一维和二维H核磁共振方法研究了柠檬酸稀土、稀土-DTPA配合物与磷脂双分子膜的作用,结果表明L在近生理条件下(PH=7.4)及 柠檬酸配体的磷脂双分子膜体系中,稀土离子首先与柠檬酸体作用,形成的配合物对磷脂双分子膜的结构影响较小,稀土-DTPA配合物对磷脂双分子膜的结构没有影响这些结果为科学地评价稀土离子进行体内的毒性提供了实验依据。 相似文献
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利用外源荧光探针研究了肥皂草素和膜脂相互作用后膜物理状态变化的特征。SO-6与磷脂双分子层作用后,可以引起双分子层内含物的释放,使磷脂双分子层发生搅动;SO-6可以降低磷双分子层膜的流动性。根据上结果,提出了肥皂草素与模拟膜作用的初步机制。 相似文献
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超声提取正相高效液相色谱法测定大豆及大豆油中的磷酸甘油酯 总被引:3,自引:0,他引:3
建立了超声提取-固相萃取纯化/正相高效液相色谱测定大豆及大豆油中磷脂酰胆碱(PC)、磷脂酰乙醇胺(PE)、磷脂酰肌醇(PI)的方法。考察了提取溶剂、超声功率、超声时间、提取温度及净化方式的影响,并研究了不同色谱固定相对磷酸甘油酯分离效果的影响。优化的实验条件为:以氯仿-甲醇(2∶1,体积比)为提取溶剂,1 500 W功率超声提取30 min;氨基固相萃取柱为纯化小柱;正己烷-异丙醇-1%HAc(8∶8∶1,体积比)为流动相。在该条件下,PC、PE、PI的线性范围分别为0.08~8.00、0.15~15.00、0.30~20.00 g.L-1,定量下限分别为0.021、0.050、0.060 g.L-1,检出限在8~23 mg.L-1之间,其在大豆和大豆油中的回收率为85%~108%。日内与日间精密度分别不大于4.7%和8.6%。 相似文献
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G Saccomani H H Chang A Spisni H F Helander H L Spitzer G Sachs 《Journal of supramolecular structure》1979,11(4):429-444
The phospholipid and fatty acid composition and role of phospholipids in enzyme and transport function of gastric (H+ + K+)-ATPase vesicles was studied using phospholipase A2 (bee venom). The composition (%) was phosphatidyl-choline (PC) 33%; sphingomyelin (sph) 25%; phosphatidylethanolamine (PE) 22%; phosphatidylserine (PS) 11%; and phosphatidylinositol (PI) 8%. The fatty acid composition showed a high degree of unsaturation. In both fresh and lyophilized preparations, even with prolonged incubation, only 50% of phospholipids were hydrolyzed, but the amount of PE and PS disappearing was increased following lyophilization. There was a marked decrease in K+-ATPase activity (75%) but essentially no loss of the associated K+ p-nitrophenyl phosphatase was found. ATPase activity could be largely restored by various phospholipids (PE greater than PC greater than PS). There was also an increase in Mg2+-ATPase activity, partially reversed in fresh preparations by the addition of phospholipids (PE greater than PS greater than PC). Proton transport activity of the preparation was rapidly inhibited, initially due to a large increase in the HCl permeability of the preparation. Associated with these enzymatic and functional changes, the ATP-induced conformational changes, as indicated by circular dichroism spectra were inhibited. 相似文献
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A method for the simultaneous determination of amounts of major phospholipid classes and their fatty acid composition in erythrocyte membranes is described. The method consists in extraction of phospholipids from erythrocyte membranes, separation of phospholipid classes by high-performance liquid chromatography, methylation of phospholipids and determination of phospholipid-bound fatty acids by capillary gas chromatography. The amounts of phospholipid classes are calculated from the total weight of phospholipid-bound fatty acids and their average molecular weights. The method was applied to erythrocytes from rats. The results show that the method is reproducible and is useful for the determination of amounts of phospholipid classes and their fatty acid composition in small blood samples. 相似文献
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Sylvie Ponchautcor Keith Veitchaff Raymond Libertaff François Van Hoofaff Louis Hueaff Edmond de Hoffmann 《Journal of the American Society for Mass Spectrometry》1996,7(1):50-58
Phosphatidylcholine (PC) is one of the main phospholipids present in mitochondrial membranes. According to current knowledge, the predominant fatty acyl moieties in this phospholipid are 16, 18, 20, or 22 carbon atoms long with chains that contain only carbon and hydrogen atoms. We have conducted a detailed analysis of the fatty acid substituents of the phospholipids present in mitochondrial fractions by using fast-atom bombardment tandem PC extracted from mitochondrial fractions of rat heart. The structure of one of these monohydroxylated fatty acids has been elucidated and corresponded to 12-hydroxy 9-octadecenoic acid. Indications that concern the structure of the five other monohydroxylated fatty acids are presented. These monohydroxylated fatty acyl groups are preferentially associated in the PC molecule with C-18 and C-20 fatty acyl moieties. We present arguments to suggest that the formation of these compounds is probably not due to a free-radical initiated mechanism. The potential implication of these monohydroxylated fatty acids in several physiological functions is suggested by the fact that free hydroxylated fatty acids that are identical or closely related to those found in the mitochondrial fractions possess various biological activities. 相似文献
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Micellar electrokinetic capillary chromatography (MECC) with laser-induced fluorescence detection was applied to the separation of amino group-containing phospholipids including phosphatidylethanolamine (PE), phosphatidylserine (PS), lysophosphatidylethanolamine (LysoPE), and lysophosphatidylserine (LysoPS). A fluorogenic dye, 3-(2-furoyl)quinoline-2-carboxaldehyde (FQ), was successfully used to fluorescently label these phospholipids. 4-Fluoro-7-nitrobenzofurazan only produced fluorescent product from LysoPE and PE; signals were not observed from LysoPS and PS. A borax buffer containing sodium deoxycholate modified with methyl-beta-cyclodextrin (methyl-beta-CD) was an excellent MECC system for these phospholipids. Under the optimum conditions, four FQ-labeled phospholipid classes were separated within 8 min. Moreover, each of the PE, PS, LysoPE and LysoPS peaks split into two components corresponding to subclasses with different lengths of the fatty acid chains, but these subclasses were completely resolved only for LysoPE. Detection limits ranged from 0.18 to 1.1 fg (10(-9) - 10(-10) M), which was four- to five-orders of magnitude superior to previously reported CE methods. 相似文献
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The lipid composition of rat caecal mucosa, including the fatty acid composition of phospholipids and triacylglycerols, has been examined by capillary gas chromatography. Thirty-seven peaks were resolved, ranging in chain length from 12 to 24 carbon atoms. Preliminary identification of fatty acids by comparison with authentic standards was confirmed by gas chromatography-mass spectrometry using electron-impact ionization. The neutral and polar components were examined. Fatty acid methyl esters were quantified in absolute amounts with respect to the percentage of total phospholipid and triacylglycerols. The results show significantly higher levels of 16:0, 18:0, 18:1(n-9), 18:1(n-7), 18:2(n-6) and 20:4(n-6) in phospholipids, and higher levels of 16:0, 18:1(n-9) and 18:2(n-6) in triacylglycerols. On the other hand, analysis of caecal triacylglycerols revealed sn-glycerol-palmitate-oleate-palmitate, sn-glycerol-palmitate-linoleate-palmitate and sn-glycerol-palmitate-linoleate-oleate as major components. 相似文献
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H. M. Liebich B. Jakober C. Wirth A. Pukrop M. Eggstein 《Journal of separation science》1991,14(7):433-437
Total lipids have been extracted from human serum with chloroform–methanol 2:1 (v/v) and separated into individual classes by TLC. After transesterification the fatty acid methyl esters were analyzed by capillary gas chromatography on an FFAP column. The quantitation of ω-3 fatty acids has been performed using internal and external standards. Internal lipid standards for each lipid class were carried throughout the entire analytical procedure. Under normal diet eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are incorporated into the lipid classes to different extents: cholesterol esters; EPA, 6.5 ± 1.9 γ/ml serum; DHA, 4.3 ± 1.9 μg/ml: phospholipids; EPA, 5.9 ± 2.7 μg/ml; DHA, 31.8 ± 8.1 μg/ml. Fish oil supplementation leads to a 4 to 6-fold rise in EPA and to an approximately 2-fold rise in DHA. 相似文献