Glycosphingolipids isolation

Fig. 11.—Sequence of a 2S-Sugar Residue Glycosphingolipid Isolated from Rabbit Erythrocyte Membranes. (Cleavage points, and the masses of fragment ions of the permethylated derivative, are shown. No fragment-ions were observed above 4000, because of the poor sensitivity at high mass.)...

Fukuda, M.N., Dell, A., Oates, J.E., Wu, P., Klock, J.C. and Fukuda, M. (1985) Structures of glycosphingolipids isolated from human granulocytes. The presence of a series of linear poly-N-acetyllactosaminylceramide and its significance in glycolipids of whole blood cells. Journal of Biological Chemistry 260, 1067-1 082. 

Iriko, H., Nakamura, K., Kojima, H., lida-Tanaka, N., Kasama, T., Kawakami, Y., Ishizuka, I., Uchida, A., Murata, Y. and Tamai, Y. (2002) Chemical structures and immunolocalization of glycosphingolipids isolated from Diphyllobothrium hottai adult worms and plerocercoids. European Journal of Biochemistry 269, 3549-3559. 

The studies discussed above have all dealt with glycosphingolipids isolated from neutrophils that were derived from normal whole blood. Wherrett (16) has presented detailed structural analysis of a tetraglycosylceramide isolated from polymorphonuclear leukocytes obtained from the urine of a patient with a urinary tract infection. This glycosphingolipid was determined to be lactoneotetraosylceramide. 

Figure 13 - High-performance thin-layer chromatography of Aspergillus neutral glycosphingolipids isolated by latrobeads column cromatography. Lane 1 Fdch lower phase. Lane 2 Glycosphingolipid fraction obtained by silica gel chromatography. Lane 3 Chloroform fractions. Lane 4 Chloroform/methanol (95 5) fraction. Lanes 5-11 Chloroform/methanol (9 1) fractions. Lane 12-13 Chloroform/methanol (8 2) fractions. Lane 14 Methanol fraction. Solvent system ...

As for most of glycosphingolipids, vesparioside, vesparioside B and terpioside are a mixture containing amides and amino alcohols with different chain lengths. Vesparioside B is currently the most complex glycosphingolipid isolated from a marine sponge. 

Turbostatins 1-4 are glycosphingolipids isolated from Turbo stenogyrus collected in Taiwan. These four derivatives are cytotoxic to several human cancer cell lines, with IC50 values ranging from 0.15 to 2.6 (xgml(Pettit, Tang, and Knight, 2005). 

Gerdt, S., Lochnit, G., Dennis, R.D. and Geyer, R. (1997) Isolation and structural analysis of three neutral glycosphingolipids from a mixed population of Caenorhabditis elegans (Nematoda Rhabditdida). Glycobiology 7, 265-275. 

The procedure of isolating the glycosphingolipids is based on their physicochemical properties. The presence of the lipophilic, lipid moiety results in their solubility in such typical solvents for lipids as chloroform-methanol. On the other hand, the presence of the carbohydrate moiety imparts to them hydrophilic properties that increase with increase in the length of the carbohydrate chain and with the presence of such polar monosaccharides as sialic acid. This very property makes it possible to subdivide the glycolipids further, according to their polarity. In principle, the isolation of glycosphingolipids from marine animals does not differ from their isolation from other sources, a procedure comprehensively elucidated in a number of reviews.80 88... 

In brief, the isolation scheme is as follows. First, the lipids are all extracted from the animal tissue, generally by using chloroform-methanol or chloroform-methanol-water. An increase in the polarity of the extracting system makes it possible to extract more fully the polar glycosphingolipids, especially polysialoglycolipids, but may, however, lead to contamination... 

Sphingosine bases are usually isolated from glycosphingolipids by treatment with methanolic HC1 containing some water,148 and characterized, in the form of the free bases or their 2,4-dinitrophenyl (DNP) derivatives,149 151 by t.l.c. For quantitative determination of bases, a colorimetric procedure is used, based on color formation of the base with Methyl Orange.152 The composition of the sphingosine bases, as their Me3Si derivatives, is determined by g.l.c. and g.l.c.-m.s.,148,153,154 as well as by using for this purpose... 

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