A chemometric strategy for the classification of lecithins according to process performance

Lecithins are widely used as multipurpose additives in the pharmaceutical and food industries. This implies the need for an analytical means for the assessment of process performance prior to full-scale processing. A general methodology was developed for the classification of lecithins with respect to this property. The strategy developed utilizes pattern recognition methods, fatty acid composition of the phospholipid classes(phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol) and lipid class analysis by high performance liquid chromatography to identify the lecithins with acceptable performance, e.g., emulsifying behavior.     

Incorporation of unsaturated fatty acids by Saccharomyces cerevisiae: conservation of fatty-acyl saturation in phosphatidylinositol

Saccharomyces cerevisiae was grown anaerobically in media supplemented with myristoleic 14:1(9c), palmitoleic 16:1(9c), oleic 18:1(9c), linoleic 18:2(9,12c), gamma-linolenic 18:3(9,12,15c) or eicosenoic 20:1(11c) acid. Cells from exponential-phase cultures contained approximately the same proportions of the major phospholipid classes, namely phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol and phosphatidylserine, the greatest differences being detected in cells grown in the presence of 14:1(9c) or 20:1(11c) acids. The extent to which phospholipids from cells were enriched with residues of the exogenously supplied acid varied from 52% in cells grown in the presence of 14:1(9c) acid to 13% in cells grown in media supplemented with 20:1(11c) acid. Analysis of the fatty-acyl composition of the four major phospholipid classes revealed that the degree of unsaturation varied considerably in three of the classes, while phosphatidylinositol conserved a high degree of saturation. The possible significance of the latter finding in relation to the physiological role of phosphatidylinositol in the plasma membrane is discussed.     

Analysis of individual phospholipids by high-performance capillary electrophoresis

A method of analysis for determination of phospholipids by micellar electrokinetic capillary chromatography (MECC) has been developed. Sodium cholate (NaCh) was found suitable as the micellar phase, and 1-propanol was important in obtaining an efficient separation of individual phospholipids and as organic solvent required for acceptable solubility of the phospholipids. With equal volatility of water and organic modifier, only minor changes in effects from the modifier occur during analysis. The influence of changes in high-performance capillary electrophoresis-MECC separation conditions were evaluated in terms of migration time, relative migration time (RMT), relative normalized area (RNA), resolution and theoretical plates per meter. The method has several advantages compared to high-performance liquid chromatography: The total time of analysis is less than 25 min, and only small amounts of reagents and sample are required. Relative standard deviations were 0.26–0.48% for RMT, 1.7–2.9% for RNA, and in the linearity test correlation coefficients of 0.999 were obtained. Results from analyses of the phospholipid compositions of soybean and rapeseed lecithins are presented.     

Proteomic study on protective mechanism of ischemic preconditioning to ischemia-reperfusion lung injury

Objective To investigate the change of protein expression of lung tissue of rabbit after ischemic preconditioning (IP) and try to elucidate the potential protective mechanism of IP. Methods 12 domestic rabbits were randomly divided into group IP and group control(6 rabbits in each group). All the left lungs were afflicted by ische mia-reperfusion injury except that those in group IP were subject to IP prior to ischemic phase. 2-DE was employed to separate the total protein of the lung tissue. PDQuest analysis software was used to distinguish the differently expressed protein spot. MALDI-TOF-MS and Mascot database searching were exploited to identify these proteins. Results 1) IP attenuated the ischemia-reperfusion lung injury. 2) The proteomic analysis showed 35 target proteins,of which 17 were characterized such as phosphatidylinositol 3-kinase(PI3k) delta catalytic subunit. Conclusions 1)Proteomic is a promising tool to investigate the IP and ischemia-reperfusion lung injury. 2) That IP inhibits inflammatory cascades through phosphatidylinositol 3-kinase signal transduction pathway may be one of its protective mechanism.