Consecutive analysis of sphingoglycolipids on the basis of sugar and ceramide moieties by high performance liquid chromatography

Sphingolipidomics: methods for the comprehensive analysis of sphingolipids

Sphingolipids comprise a highly diverse and complex class of molecules that serve as both structural components of cellular membranes and signaling molecules capable of eliciting apoptosis, differentiation, chemotaxis, and other responses in mammalian cells. Comprehensive or "sphingolipidomic" analyses (structure specific, quantitative analyses of all sphingolipids, or at least all members of a critical subset) are required in order to elucidate the role(s) of sphingolipids in a given biological context because so many of the sphingolipids in a biological system are inter-converted structurally and metabolically. Despite the experimental challenges posed by the diversity of sphingolipid-regulated cellular responses, the detection and quantitation of multiple sphingolipids in a single sample has been made possible by combining classical analytical separation techniques such as high-performance liquid chromatography (HPLC) with state-of-the-art tandem mass spectrometry (MS/MS) techniques. As part of the Lipid MAPS consortium an internal standard cocktail was developed that comprises the signaling metabolites (i.e. sphingoid bases, sphingoid base-1-phosphates, ceramides, and ceramide-1-phosphates) as well as more complex species such as mono- and di-hexosylceramides and sphingomyelin. Additionally, the number of species that can be analyzed is growing rapidly with the addition of fatty acyl Co-As, sulfatides, and other complex sphingolipids as more internal standards are becoming available. The resulting LC-MS/MS analyses are one of the most analytically rigorous technologies that can provide the necessary sensitivity, structural specificity, and quantitative precision with high-throughput for "sphingolipidomic" analyses in small sample quantities. This review summarizes historical and state-of-the-art analytical techniques used for the identification, structure determination, and quantitation of sphingolipids from free sphingoid bases through more complex sphingolipids such as sphingomyelins, lactosylceramides, and sulfatides including those intermediates currently considered sphingolipid "second messengers". Also discussed are some emerging techniques and other issues remaining to be resolved for the analysis of the full sphingolipidome.

Use of N-acetylpsychosine as internal standard for quantitative high-performance liquid chromatographic analysis of glycosphingolipids

The use of N-acetylpsychosine as an internal standard for the quantitative high-performance liquid chromatography (HPLC) of p-nitrobenzoyl derivatives of glycosphingolipids is described. It is suitable because the chromogen reacts on equimolar basis with both N-acetylpsychosine and sample glycosphingolipids. The use of N-acetylpsychosine as an internal standard was validated by determining the glycosphingolipid content of a system of metastatic variants selected from a murine fibrosarcoma line (T3 cells). Reproducible results were obtained throughout several quantitative analyses of cellular glycosphingolipids and it was possible to determine the glycosphingolipid content of as few as 5 x 10(6) cells.

Preparative separation of sphingolipids and of individual molecular species by high-performance liquid chromatography and their identification by gas chromatography-mass spectrometry

Six fractions containing tri- to pentaglycosylceramides were isolated from the green, fresh water alga Chlorella kessleri, grown heterotrophically, by using preparative high-performance liquid chromatography (HPLC). Up to twelve fractions were obtained by further reversed-phase HPLC of each glycosylceramide. The use of a polar capillary column with Supelcowax 10 as the stationary phase allowed an excellent separation of the individual molecular species of ceramides, even though the separation did not occur when the ceramides differed only in the position of the amide bond. The individual molecular species (even if present in mixtures) were identified by gas chromatography-chemical ionization mass spectrometry. The evidence for a complete structure was obtained by enzyme splitting with alpha- and beta-galactosidases (the sequence of monosaccharides) and by negative ionization fast atom bombardment mass spectrometry. More than 400 molecular species of glycosylceramides were identified.

Urinary neutral glycosphingolipid analysis of patients with Fabry's disease; rapid isocratic elution from high-performance liquid chromatography as per-o-benzoyl derivatives

Neutral glycosphingolipids from urinary sediments of six patients with Fabry's disease and 11 members of the family of one propositus were analyzed using high-performance liquid chromatography. Per-o-benzoyl derivatives of GlcCer, LacCer, GbOse3Cer and GbOse4Cer were clearly resolved by a solvent mixture of hexane/dioxane/isopropanol (75:25:1, v/v) on a normal-phase silica column. Using our isocratic solvent system, the analysis was completed within 15 min. The smallest amount of glycolipid that could be detected by HPLC was 50 pmol and a linear response was shown at 230 nm up to 400 pmol. The calculated peak area of GbOse4Cer was higher than those of GlcCer, LacCer and GbOse3Cer. The molar ratios of GbOse3Cer to monohexosyl ceramide (CMH) in the urinary sediments were: Fabry hemizygotes, 36.33 +/- 25.54 (n = 6); heterozygotes, 0.94 +/- 0.50 (n = 4); and controls, 0.11 +/- 0.06 (n = 5). The molar ratio CDH/CMH was also higher in patients (8.42 +/- 6.23) than in controls (0.77 +/- 0.23). The female H was a rare example of a carrier with typical clinical manifestations. From the urinary sediment analysis, females E, G and J were suspected to be Fabry heterozygotes, although no clinical signs were observed at the time of examination.

Chapter 12 Compound Biopolymers and Biooligomers

This chapter is devoted to the separation of simple saccharides. In this chapter, the rapid chromatographic separation of natural oligomeric or polymeric compounds containing important molecular moieties of a different type are discussed, such as nucleoprotein complexes, glycolipids, glycopeptides and glycoside oligomeric derivatives. In addition, separations of several natural complex substances that are not well known are discussed. This chapter concludes with a brief discussion on the separation techniques used for the miscellaneous polymeric and oligomeric substances.

Analysis of ceramide and monohexaosyl glycolipid derivatives by high-performance liquid chromatography and its application to the determination of the molecular species in tissues

Several molecular species of monohexaosyl glycolipids and ceramides were analyzed as their benzoyl derivatives by high-performance liquid chromatography on a silica column with mixtures of dioxane and hexane as eluents. Monohexaosyl glycolipid derivatives were classified according to their hydrophobic structures, and ceramides were separated based on the fatty acid groups and the long-chain bases. The method allowed us to observe the heterogeneities in the molecular species of cerebrosides and ceramides from the epidermis and dermis of the guinea pig, and clear differences in the molecular species were observed between the different regions.

A rapid preparative method for isolation of neutral and acidic glycosphingolipids by radial thin-layer chromatography

An efficient method to separate neutral and acidic glycosphingolipids (GSLs) from their mixtures within a short period (45-60 min) and with low consumption of solvents (chloroform-methanol-water, 60/35/8 (v/v/v); 250-500 ml) has been developed. This method utilizes a centrifugal thin-layer chromatograph (Chromatotron) and the GSL mixtures (30-400 mg) are applied to glass plates coated with a 1-mm layer of silica gel 60 PF-254. The method (radial thin-layer chromatography) is rapid and simple and the recovery of glycosphingolipids is high (70-80%).