中藥紫河车中磷脂组分的~(31)P核磁共振光谱及薄層色谱-吸光度比例系数校正法研究

本文应用~(31)P核磁共振光谱和薄层扫描-吸光度比例系数校正法对補益中药紫河车中的磷脂组分进行了定性及定量分析。结果表明,两种方法检出的磷脂组分一致,薄层扫描定量结果与~(31)P核磁共振定量结果基本一致。两种方法都具有快速、灵敏、样品用量少的优点,~(31)P核磁共振光谱测定具有更高的准确度和重现性。     

Temperature scanning X-ray diffraction at phase transitions of biologically related lipid assemblies

Summary Based upon the results of ac calorimetry and temperature scanning X-ray diffraction in the phospholipid/cholesterol system, the phase diagram was constructed by taking into account the ripple structure. From the analysis of the cholesterol concentration dependence of the modified ripple structure the cholesterol-rich state which lies in the higher cholesterol concentration than 20 mol% in the phase diagram is proposed. It is proposed that this is a fundamental complex that appears generally in lipid/cholesterol systems.     

Lipidomic study and diagnosis of hepatocellular carcinoma tumor with rapid evaporative ionization mass spectrometry

Liver cancer is generally considered the leading cause of cancer deaths worldwide, and hepatocellular carcinoma (HCC) contributes to more than 90% of liver cancers. The altered lipid metabolism for rapid cancer cell growth and tumor formation has been frequently proven. In this study, an ambient ionization mass spectrometry technique, rapid evaporative ionization mass spectrometry (REIMS) using a monopolar electric knife, called iKnife, was systematically optimized and employed for ex vivo analysis of 12 human HCC tumor tissue specimens together with the paired paracancerous tissue (PT) and noncancerous liver tissue (NCT) specimens. Nine free fatty acids and 34 phospholipids were tentatively identified according to their extract masses and/or tandem mass spectra. With the help of statistical methods, 7 free fatty acids and 10 phospholipids were distributed differently in 3 types of liver tissue specimens (95% confidence interval). The box plots showed these characterized lipid metabolites varied in PT, HCC, and NCT. Compared with PT and NCT, the upregulations of four common fatty acids FA 18:0, FA 20:4, FA 16:0, and FA 18:1, together with phospholipids PC 36:1, PE 38:3, PE (18:0/20:4), PA (O-36:1), PC (32:1), PC 32:0, PE 34:0, and PC (16:0/18:1), were found in HCC specimens. The sensitivity and specificity of the established statistic model for real-time HCC tumor diagnosis were 100% and 90.5%, respectively. This study demonstrated that the described REIMS technique is a potential method for rapid lipidomic analysis and characterization of HCC tumor tissue.     

Microbial growth on pall rings

Biogas is upgraded using an absorption with water-wash technique by 11 of a total of 14 upgrading plants in Sweden. However, problems with microbial growth on the pall rings in the absorption column, and in one case in the desorption column, have a negative impact on the upgrading of raw gas to vehicle gas. Five of the nine biogas plants studied here have experienced problems with microbial growth. The objectives of this study were to identify such microbial growth and to determine possible factors for its control, in order to provide recommendations for process management. A questionnaire was sent out and visits were made to the upgrading plants to collect information about the upgrading process. Phospholipid fatty acid (PLFA) analysis was performed to determine microbial biomass and community structure in samples from four upgrading plants. In samples from two of the plants, methane-oxidizing bacteria (type I methanotrophs) were indicated, while samples from one of the other plants showed biomarkers indicating actinomycetes. Factors affecting development of microbial growth were found to be water quality and the pH and temperature of the process water. Plants that used wastewater in the upgrading process experienced far more problems than those using clean water of drinking quality.     

Comparative Study on Curcumin Loaded in Golden Pompano (Trachinotus blochii) Head Phospholipid and Soybean Lecithin Liposomes: Preparation,Characteristics and Anti-Inflammatory Properties

In this study, we compared the characteristics and in vitro anti-inflammatory effects of two curcumin liposomes, prepared with golden pompano head phospholipids (GPL) and soybean lecithin (SPC). GPL liposomes (GPL-lipo) and SPC liposomes (SPC-lipo) loaded with curcumin (CUR) were prepared by thin film extrusion, and the differences in particle size, ζ-potential, morphology, and storage stability were investigated. The results show that GPL-lipo and SPC-lipo were monolayer liposomes with a relatively small particle size and excellent encapsulation rates. However, GPL-lipo displayed a larger negative ζ-potential and better storage stability compared to SPC-lipo. Subsequently, the effects of phospholipids in regulating the inflammatory response of macrophages were evaluated in vitro, based on the synergistic effect with CUR. The results showed that both GPL and SPC exerted excellent synergistic effect with CUR in inhibiting the lipopolysaccharide (LPS)-induced secretion of nitric oxide (NO), reactive oxygen species (ROS), and pro-inflammatory genes (tumor necrosis factor (TNF)-α, interleukin 1β (IL-β), and interleukin 6 (IL-6)) in RAW264.7 cells. Interestingly, GPL-lipo displayed superior inhibitory effects, compared to SPC-lipo. The findings provide a new innovative bioactive carrier for development of stable CUR liposomes with good functional properties.     

A new liquid crystal-based method to study disruption of phospholipid membranes by sodium deoxycholate

In this study, we have used liquid crystals (LCs) to investigate the mechanism and dynamics of structural change of phospholipid membranes caused by sodium deoxycholate (NaDC). Addition of the NaDC aqueous solution to the phospholipid [1,2-dioleoyl-sn-glycero-3-phospho-rac-(1-glycerol) sodium salt (DOPG)] modified aqueous/LC interface resulted in the interaction-induced change of the orientational arrangement of the LCs from a homeotropic state to a planar state. The importance of contributing parameters was determined by observing the changes in the orientation of LCs. We showed that this interaction was affected by reaction time, reaction pH, concentration of NaDC and the presence of cholesterol. Moreover, the phospholipid membrane, which became defective after being exposed to NaDC, was capable of self-repairing by excess Tris-buffered saline solution, indicating that the reaction of NaDC with the phospholipid membrane is reversible. The obtained results proved the feasibility of the method deploying the DOPG/LC interface to monitor the membrane reaction stemming from the interaction between a bioactive molecule and a phospholipid membrane.     

Recruitment and Immobilization of a Fluorinated Biomarker Across an Interfacial Phospholipid Film using a Fluorocarbon Gas

Perfluorohexane gas when introduced in the air atmosphere above a film of phospholipid self‐supported on an aqueous solution of C₂F₅‐labeled compounds causes the recruitment and immobilization of the latter in the interfacial film. When the phospholipid forms a liquid‐condensed Gibbs monolayer, which is the case for dipalmitoylphosphatidylcholine (DPPC), the C₂F₅‐labeled molecule remains trapped in the monolayer after removal of F‐hexane. Investigations involve bubble profile analysis tensiometry (Gibbs films), Langmuir monolayers and microbubble experiments. The new phenomenon was utilized to incorporate a hypoxia biomarker, a C₂F₅‐labeled nitrosoimidazole (EF5), in microbubble shells. This finding opens perspectives in the delivery of fluorinated therapeutic molecules and biomarkers.     

支撑磷脂双层膜的研究进展

支撑磷脂双层膜(supported phospholipid bilayers,SPBs)是细胞膜研究中普及的模型,是固定生物活性物质的理想材料,不仅可以保持生物分子的活性,还能有效抑制其他生物分子的非特异性吸附,在跨膜蛋白、仿生膜、水处理、生物医学和生物传感器等研究领域具有广泛的应用前景。本文介绍了支撑磷脂双层膜的表征方法和制备方法,包括Langmuir Blodgett(LB)膜提拉法、囊泡融合法和LB膜提拉法与囊泡融合联合法;详细阐述了囊泡融合法制备SPBs的机理;综述了囊泡融合法制备SPBs的影响因素,包括囊泡浓度、缓冲溶液、温度、囊泡和基底表面电荷等因素;列举了支撑磷脂膜的应用,并展望了支撑磷脂双层膜的研究趋势。     

Gas Chromatographic Study of Phosphatidyl Serines

Abstract

The reaction of silylating agents (BSA-TMCS) and phosphatidyl serines leads to the formation of 1,2-diglyceride trimethylsilyl (TMSi) ethers, along with small amounts of related 1,3-diglyceride trimethylsilyl ethers. The major product from a bovine phosphatidyl serine fraction was found to be 1-stearoyl-2-oleoylglycerol TMSi ether (the isomeric structure 1-oleoyl-2-stearoylglycerol TMSi ether may also be present). Related diglycerides were also found as products. The reaction products were identified by gas chromatography-mass spectrometry. The mechanism of the reaction is unknown, but it provides a way of studying the composition of phosphatidyl serine fractions without prior enzymic or chemical hydrolysis.     

Modeling of 31P-NMR spectra of magnetically oriented phospholipid liposomes: A new analytical solution

³¹P-NMR spectroscopy is widely used for studies of phospholipid liposomes, a commonly used model of a biological membrane. For the correct analysis of ³¹P-NMR spectra of the liposomes it is necessary to take into account that they are deformed by the magnetic field of the spectrometer. The liposomes become ellipsoidal and this affects the lineshape of the spectrum. In the present communication we suggest a new analytical formula for modeling of ³¹P-NMR spectra of the prolate phospholipid liposomes. The formula assumes a Lorentzian broadening function and exactly ellipsoidal shape of the liposomes. Based on the formula a program called P-FIT is designed for the practical analysis of the experimental multicomponent spectra of the prolate liposomes. The versatility of the program developed in a Mathematica environment is demonstrated by simulations of a number of ³¹P-NMR spectra with different complexity.