Cerebrosides types

From the same sources, Wagner and Zofcsik132 have isolated a gly-cosphingolipid of a cerebroside type, namely, the dihydro-D-galacto-cerebroside 60. 

Although cerebroside sulfate has been reported to interact strongly with opiates C14-16), enkephalin has so far shown no significant binding in the present type of experiment to an egg lecithin C27 mg) - sulfatide (25 mg) mixture at pH 6.3 and 7.1. Further studies are currently underway with this system. 

In general the sphingolipids are located on the exterior face of a membrane while the phospholipids make up the inner face. This is understandable when we recall that sphingolipids include the gangliosides and cerebrosides whose polar ends contain carbohydrates or complex carbohydrate derivatives. The large number of chiral centers in carbohydrate molecules offer a complex pattern on the surface of the membrane which can impart a large degree of specificity for a particular cell type. The composition and limited fluidity of the bilayer make the entire membrane asymmetric, that is, different on the inner and outer layers or leaflets. 

At higher emitter currents, fragment ions became more significant in the spectra. A survey of compound types yielded the spectra shown in Figures 9 and 10A+B, obtained for psychosine, N-stearoyl dihydroglucocerebroside and N-stearoyl dihydrolacto-cerebroside, respectively. 

Formation of membrane structures is also due to the hydrophobic effect. When a molecule is composed of both polar and nonpolar moieties, it is said to be amphiphilic. Since the hydrophobic effect is concerned with the tendency for nonpolar molecules or nonpolar components of molecules to associate spontaneously in aqueous solutions, there is a wide range of small molecules such as fatty acids and phospho- and glycolipids which, when dissolved in water, segregate to form membranes or micelles [146]. The same type of segregation occurs in the crystalline state, as in the structures of the long chain alkyl glycosides [147], cerebrosides,... 

In 1989, Hamanaka and coworkers isolated a new esterified cerebroside from human epidermis, and found it to be a linoleic acid-containing acylglucosylceramide (162, Figure 6.24). She later named 162 type I epidermoside, because it was specific to epidermis. Her works have been reviewed.35 The same structure... 

A new type of glycosphingolid was isolated from beef brain by Kochetkov, Zhukova, and Glukhoded.88 For the structure of this glycosphingolipid, a sphingoplasmogen, the cerebroside-3-enol ether (41) was proposed. 

Hydroxy FA occnr in both satnrated and nnsatnrated forms, with varions positional isomers. There are three major types. First, the 2-hydroxy (2-OH) or a-hydroxy FA (Fignre 3.1). These satnrated components occnr as a series of even nnmbered acids from Cm to C26 and are components of animal tissnes (within cerebrosides) and certain plants. Second, 3-hydroxy (3-OH) or P-hydroxy FA exist as a series of even-nnmbered acids from Cm to C. They are ubiquitous components of many bacteria and yeasts, where they exist as ester-linked residues of extracellular lipids. Third, the hydroxyl group may be present at the penultimate carbon from the carboxyl group (i.e., co2, or otherwise referred to as co-1) of the chain series Cn to Cm- In most instances, these compounds represent intermediates in the co-oxidation of FA by microorganisms. 

Studies on spinal cord myelin lipid composition in mouse model of ALS indicate that levels of lipids, phospholipids, cholesterol, and cerebrosides are decreased compared to wild-type mice (Table 8.4) (Niebroj-Dobos et al., 2007). Although a progressive decrease in proteolipid, DM-20, and Wolfgram proteins occurs in this ALS model, myelin basic proteins I and n are not affected. Electron microscopy indicates massive myelin disorganization (Niebroj-Dobos et al., 2007). Production... 

Glycolipids are another type of sphingolipid. Unlike sphingomyelins, however, these complex lipids contain carbohydrates (usually monosaccharides such as glucose or galactose). Glycolipids are often called cerebrosides because of their abundance in brain tissue. The structure of a typical cerebroside is... 

The presence of 2-hydroxylated fatty acids can be easily determined by C NMR spectroscopy in cerebrosides containing sphingosine-type bases due to the chemical shift of C-2 (72.5 ppm). In cerebrosides with phytosphingosine-type bases, C-4 in the long-chain base and C-2 hydroxy-lated in the fatty acid moiety show similar chemical shifts [6]. 

A new glucocerebroside, linckiacerebroside A (10) (Fig. 6), together with nearly homogeneous cerebrosides containing phytosphingosine-type long-chain bases and 2-hydroxy fatty acids, was isolated from the starfish Linckia laevigata [46]. 

Recently, 21 galactosylceramides bearing phytosphingosine-type Iraig-chain bases, including 16 new compounds (22-37) (Fig. 10), were identified from a cerebroside molecular species obtained from the starfish Protoreaster nodosus [53]. Fifteen of the cerebrosides were isolated as pure compounds, while three pairs of isomeric glactosylceramides were obtained as inseparable mixtures. 

Chemical investigation of the feather star Comanthus japonica yielded two new p-glucocerebrosides (43 and 44) and two known compounds. One of the new cerebrosides (39) is unique in that it is the first type of glucosylcer-amide isolated from an echinoderm composed of a ph3 tosphingosine base and a nonhydroxylated fatty acyl moiety (Fig. 15) [58]. 

Two new phytosphingosine-type cerebrosides mixtures (45 and 46) containing iV-acetylglucosamine were isolated from the marine sponge Oceanapia sp. (Fig. 16) [31 ]. They proved to be new variants of iV-acetylglucosamine-containing... 

Two new sphingosine-type glucocerebrosides, sarcoehrenosides A (69) and B (70), were isolated from the alcyonacean soft coral S. ehrenbergi (Fig. 19) [28]. Compound A differs from previously known marine cerebrosides in that it possesses a rare a-D-glucose moiety. Both compounds, together with four known glucocerebrosides isolated from the same coral, were evaluated for antimicrobial activity against a small panel of five bacterial strains. None of the compounds exhibited antibacterial activity at a concentration of 100 pg/disk. 

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