Glycolipids improve lutein bioavailability and accumulation in eyes in mice

Intestinal carotenoid absorption is greatly affected by dietary factors. In this study, it was hypothesized that lipids with varying functional groups may influence differentially lutein bioavailability. Hence, the influence of glyco‐, phospho‐, neutral, crude (mixture of lipids) lipids, or mixed micelles (control) on the percent lutein micellarization in vitro and its postprandial plasma, liver, and eye response in mice were investigated. Results show that the percent micellarization of lutein with crude lipids and glycolipids were higher (91.4 and 45.7%) than control, while no significant difference was found between phospho‐ and neutral lipids. The mean plasma response of lutein was higher for crude‐ (6 times), glyco‐ (3 times), phospho‐ (2.7 times), and neutral (2 times) lipid than control (12.4 ± 1.18 nmol/mL 8 h^?1) group. Lutein levels (pmol/g) in liver were higher in crude (7.4 ± 1) and phospho‐ (3.6 ± 0.8) lipid groups while in eyes it was higher in glyco‐ (54.0) and neutral (21.2) lipid groups than control. The influential effect of glyco‐ and phospholipids may be due to smaller micellar size (glyco‐upto 3.43 µm, phospho‐ upto 5.78 µm) than the neutral lipids (upto 66 µm). Ingestion of lutein with glycolipid or phospholipids may improve lutein bioavailability. Practical applications: The findings of the present study will be useful in nutritional and biomedical applications for feeding lutein with specific lipid combinations to achieve enhanced lutein absorption. Specifically, feeding diet/emulsion with lutein and glyco‐ and phospholipid combination may reduce the risk of macular degeneration, owing to the influential effect of these lipids on intestinal absorption of lutein.     

Differences in content and composition of free lipids and carotenoids in flour of spring and winter wheat cultivated in Poland

The work presents the content and composition of free lipids and carotenoids in spring and winter classes of wheat flour. It discusses genetical and physiological aspects of their synthesis and accumulation in wheat kernels and also indicates how methodological differences explain differences in results presented in the literature. It has been reported that spring wheat flours are richer in free lipids, especially in the non-polar fraction. The content of glycolipids ranged from 134 to 215 mg/100 g flour and was more stable within the winter wheat class. The percentages of the two main fractions, namely DGDG and MGDG, were similar in both wheat classes and reached ca. 77%. Phospholipids constituted the smallest fraction of the flour free lipids in both wheat classes; however, spring wheat flours were richer in these compounds, which is likely associated with a greater content of spherosomes in the endosperm of this wheat class. The free lipids of spring wheat flour contained more oleic and slightly less linoleic and linolenic acids. Spring wheat flour was also richer in carotenoids, although there were varieties in both classes that deviated from this. The main carotenoid was lutein, whose total percentage in the form of different isomers ranged from 71.3% to 83.3% and was slightly lower for spring wheat flour. Lutein, in the form of a trans-isomer, constituted about 62% and 70% of all carotenoids in spring and winter wheat flours, respectively.     

Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: an update for 2007-2008

This review is the fifth update of the original review, published in 1999, on the application of MALDI mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2008. The first section of the review covers fundamental studies, fragmentation of carbohydrate ions, use of derivatives and new software developments for analysis of carbohydrate spectra. Among newer areas of method development are glycan arrays, MALDI imaging and the use of ion mobility spectrometry. The second section of the review discusses applications of MALDI MS to the analysis of different types of carbohydrate. Specific compound classes that are covered include carbohydrate polymers from plants, N- and O-linked glycans from glycoproteins, biopharmaceuticals, glycated proteins, glycolipids, glycosides and various other natural products. There is a short section on the use of MALDI mass spectrometry for the study of enzymes involved in glycan processing and a section on the use of MALDI MS to monitor products of the chemical synthesis of carbohydrates with emphasis on carbohydrate-protein complexes and glycodendrimers. Corresponding analyses by electrospray ionization now appear to outnumber those performed by MALDI and the amount of literature makes a comprehensive review on this technique impractical. However, most of the work relating to sample preparation and glycan synthesis is equally relevant to electrospray and, consequently, those proposing analyses by electrospray should also find material in this review of interest.     

Molecular Ion-Independent Quantification of Polar Glycerolipid Classes in Marine Plankton Using Triple Quadrupole MS

Polar glycerolipids are a diverse family of lipid molecules that form the bulk of bacterial and eukaryotic microbial membranes. The earth and ocean sciences has a long history of using fatty acids as biomarkers for microbes, but have only recently begun to examine the intact polar lipids from which they are derived. Current analytical approaches rely on laboriously quantifying the molecular ions of each of these species independently. Thus, we saw a need for a method for quantifying polar glycerolipid classes that was: (i) selective for individual classes, (ii) inclusive of all species within a class, (iii) independent of foreknowledge of the molecular ions of the polar glycerolipid, and (iv) amenable to automated, high-throughput data analysis methods. Our new HPLC-electrospray-ionization triple-quadrupole MS (HPLC-ESI-TQMS) method can be applied to quantify the nine major classes of polar glycerolipid in planktonic communities: the phospholipids phosphatidylglycerol, phosphatidylethanolamine, and phosphatidylcholine; the glycolipids monoglycosyldiacylglycerol, diglycosyldiacylglycerol and sulfoquinovosyldiacylglycerol; and the betaine lipids diacylglyceryl trimethyl homoserine, diacylglyceryl hydroxymethyl trimethyl-β-alanine, and diacylglyceryl carboxyhydroxymethylcholine. The analyses rely on neutral loss and parent ion scan events that yield one chromatogram for each class of polar glycerolipid, simplifying downstream analysis and increasing sample throughput. The efficacy of the method was demonstrated by analyzing plankton community samples from a variety of marine environments.     

Non-methylene Interrupted and Hydroxy Fatty Acids in Polar Lipids of the Alga Grateloupia turuturu Over the Four Seasons

Phospholipids (PL) and glycolipids (GL) FA in the edible Rhodophyta Grateloupia turuturu, from Brittany, France, were investigated over four seasons. The major lipid class was GL in all seasons (around 45 %). More than 80 FA occurred in polar lipids, with chains from C₁₂ to C₂₆, identified as methyl esters and N-acyl pyrrolidides by gas chromatography–mass spectrometry (GC–MS). PUFA occurred at up to 47.1 % (summer) in PL, and up to 43.6 % (summer) in GL. The major PUFA were 20:5n-3 (12.2 % in PL and 29.0 % in GL) and 20:4n-6 (25.6 % in PL and 10.4 % in GL). The unusual 18:3n-7 acid was identified in PL up to 2.2 %. Several minor unsaturated FA were identified in PL and are previously unreported in seaweeds, namely 14-tricosenoic, 15-tetracosenoic, 5,11-octadecadienoic and 5,9-nonadecadienoic. Also unprecedented in seaweeds, ten 2-hydroxy and three 3-hydroxy FA occurred mainly in PL, 13.9 % in spring with the 3-hydroxyhexadecanoic acid as the major one (8.1 % winter). Three n-9 monounsaturated 2-hydroxy FA occurred in PL. The 2-hydroxy-15-tetracosenoic acid was characterized as the dimethyl disulfide adduct of its methyl ester. The 2-hydroxy-16-pentacosenoic and 2-hydroxy-17-hexacosenoic acids were identified by comparison of mass spectra and GC mobilities with those of the 2-hydroxy-15-tetracosenoic acid, and of other homogeneous FA series. These rare n-9 monounsaturated 2-hydroxy FA are unprecedented in seaweeds.     

Liposome: classification,preparation, and applications

Liposomes, sphere-shaped vesicles consisting of one or more phospholipid bilayers, were first described in the mid-60s. Today, they are a very useful reproduction, reagent, and tool in various scientific disciplines, including mathematics and theoretical physics, biophysics, chemistry, colloid science, biochemistry, and biology. Since then, liposomes have made their way to the market. Among several talented new drug delivery systems, liposomes characterize an advanced technology to deliver active molecules to the site of action, and at present, several formulations are in clinical use. Research on liposome technology has progressed from conventional vesicles to ‘second-generation liposomes’, in which long-circulating liposomes are obtained by modulating the lipid composition, size, and charge of the vesicle. Liposomes with modified surfaces have also been developed using several molecules, such as glycolipids or sialic acid. This paper summarizes exclusively scalable techniques and focuses on strengths, respectively, limitations in respect to industrial applicability and regulatory requirements concerning liposomal drug formulations based on FDA and EMEA documents.     

The Relative Proportions of Different Lipid Classes and their Fatty Acid Compositions Change with Culture Age in the Cariogenic Dental Pathogen Streptococcus mutans UA159

The oral cariogenic bacterial pathogen Streptococcus mutans strain UA159 has become an important research organism strain since its genome was sequenced. However, there is a paucity of information on its lipidome using direct analytical biochemical approaches. We here report on comprehensive analyses of the major lipid classes and their fatty acids in cells grown in batch standing cultures. Using 2-D high-performance thin-layer chromatography lipid class composition changes were detected with culture age. More lipid components were detected in the stationary-phase compared to log-phase cells. The major lipids identified included 1,3-bis(sn-3′-phosphatidyl)-sn-glycerol (phosphatidylglycerol), 1,3-diphosphatidylglycerol (cardiolipin), aminoacyl-phosphatidylglycerol, monoglucosyldiacylglycerol, diglucosyldiacylglycerol, diglucosylmonoacylglycerol and, glycerophosphoryldiglucosyldiacylglycerol. Culture age also affected the fatty acid composition of the total polar lipid fraction. Thus, the major lipid classes detected in log-phase and stationary-phase cells were isolated and their fatty acids were analyzed by gas–liquid chromatography to determine the basis for the fatty acid compositional changes in the total polar lipid fraction. The analyses showed that the relative proportions of these acids changed with culture age within individual lipid classes. Hence fatty acid changes in the total polar lipid fraction reflected changes in both lipid class composition and fatty acid compositions within individual lipid classes.     

Binding of Bifidobacterium bifidum and Lactobacillus reuteri to the carbohydrate moieties of intestinal glycolipids recognized by peanut agglutinin

We examined binding of Bifidobacterium bifidum and Lactobacillus reuteri to the carbohydrate moieties of glycolipids extracted from human enterocyte-like Caco-2 cells in this study. In binding assays to reference glycolipids of different carbohydrate compositions, B. bifidum EB102 bound strongly to gangliotetraosylceramide (asialo-GM1) and less strongly to gangliotriaosylceramide (asialo-GM2), lactosylceramide and sulfatide. The binding profile of B. bifidum EB102 was almost identical to that of L. reuteri JCM1081 described previously [Lett. Appl. Microbiol. 27 (1998) 130]. When we examined binding to neutral glycolipids extracted from Caco-2 cells, the binding profiles of B. bifidum EB102 and L. reuteri JCM1081 were very similar to that shown by peanut agglutinin (PNA). Binding of both strains to periodate-treated intestinal glycolipids was completely abolished, suggesting that the bacterial cells bind to carbohydrate moieties of the glycolipids. Furthermore, B. bifidum EB102 was found to express multiple glycolipid-binding proteinaceaous components on the cell surface. These results strongly suggested involvement of cell-surface proteinaceous components of B. bifidum in binding to the carbohydrate moieties of intestinal glycolipids recognized by PNA. Binding ability of B. bifidum and L. reuteri to intestinal glycolipids may play a crucial role for colonization on the mucosal surface of the intestine.     

Quantitative Determination of Natural Glycolipids from Oil Seed by Automated High‐Performance Thin‐Layer Chromatography (HPTLC)

The role of glycolipids in vegetable oil refining and production of bio‐based fuels has not been disclosed so far. Such investigations required a reliable and reproducible quantitative determination of these compounds. Fundamental data were therefore established on the quantitative determination of glycolipids in vegetable oil gums by means of high‐performance thin‐layer chromatography (HPTLC). Concentrating on five abundant natural glycolipid classes found in these oils, identification of a suitable separation method for the employed glycolipid mixture and those parameters relevant for successful detection were considered in detail. The special importance of sample volume when employing quantitative HPTLC was discussed. Acetone/chloroform/water 6:3:0.4 (v/v/v) was identified as a convenient mobile phase for the investigated issue. A derivatization reagent comprising methanol, copper(II)sulfate pentahydrate, sulfuric acid 98 %, and phosphoric acid 85 % was identified. Subsequent heating at 135 °C for 10 min finished the derivatization and enabled detection at λ = 370 nm. Calibration curves ranging from 1500 to 31.25 ng/mL, regarding both peak area and peak height, were determined. The good correlation of parameters enabled the application of the method to real oil gum samples from sunflower and soybean oil. This revealed that digalactosyldiglycerides in combination with either sterylglucosides or acylated sterylglucosides represented the major glycolipid classes in these oils.     

Pyroelectric detection in glycolipid thin film

The pyroelectric and dielectric properties of glycolipid thin films have been investigated. The glycolipid under studied is (2-n-decyl-n-tetradecyl)-4-O-maltoside. From the thin film observations using polarizing optical microscopy, glycolipid molecules were found to align homeotropically, which results in non-zero temperature-dependent spontaneous polarization. The pyroelectric coefficient, dielectric constant, dielectric loss tangent and figure of merit of the glycolipid thin films are found to be in the range of 70-105 μC m^− 2 K^− 1, 5.9-16, 0.242-0.523 and 24-88 μC m^− 2 K^− 1 respectively, depending on the glycolipid concentration. Higher concentration of glycolipid renders higher pyroelectric coefficient but lower dielectric constant and dielectric loss tangent, which then results in a higher figure of merit.