Monoglycosyl ceramide

Figure 12.14 Monoglycosyl ceramides (cerebrosides). R is an acyl chain. The carbohydrate residue of galactose is shown although this may be replaced by another hex-ose. Glycosyl ceramides containing between two and six carbohydrate residues are also found but only the mono derivatives are referred to as cerebrosides.

Direct probe analysis. The spectra of the methylated derivatives of fractions I-IV are shown in Figure 2 (a-d), together with abbreviated structured formulas and indications of some fragments (Refs. l-6 were consulted for comparison). Only fraction I gave ions indicative of the entire molecule at m/z 894 (M-l) and m/z 863 (M-32) for a monoglycosyl-ceramide containing Cj6>q fatty acid and Cjg.j long chain base. 

With bilayer lipid membranes it is not possible to achieve a fully asymmetric arrangement of head groups or chains. There is no apparent reason why all the molecules of two independent layers should only concentrate in one layer. Nevertheless, a little asymmetric distribution is found in vesicles made of lipid mixtures. Cerebroside sulfate, an anionic monoglycosyl ceramide was, for example, added exclusively to the outer surface of a performed DPPC vesicle (see Scheme 2.2) which was quantitized by the metachromatic effect of acridine orange. 

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