Long-chain base

FIGURE 14.39 The minerals commonly called asbestos (from the Creek words meaning "not burning") are fibrous because they consist of long chains based on Si04 tetrahedra linked through shared oxygen atoms. 

FIGURE 9.4 TLC-blotting/SIMS of various glycosphingolipids. (A) TLC profile of the separated glycosphingolipids, (B) MS profiles obtained by TLC-blotting/SIMS (a) spectrum of sulfatide peaks at m/z 862, 876, 890, 906, and 918 are molecular ions with different fatty acid species indicated in the figure (asterisks are peaks of triethanolamine as matrix) (b) spectrum of Gb Cer peaks at m/z 1309 and 1337 are molecular ions with different fatty acid species as indicated (c) spectrum of G peaks at m/z 1151, 1235, and 1263 are molecular ions with different fatty acid species as shown. Abbreviations LCB — long chain base, FA — fatty acid, hFA — hydroxyfatty acid. Hex — hexose, HexNAc — /V-acetylhexosamine. (From Taki, T. et al.. Anal. Biochem., 225, 24—27, 1995. With permission.) Continued. 

Morrison, W. R. 1969. Polar lipids in bovine milk. I. Long-chain bases in sphingomyelin. Biochim. Biophys. Acta 176, 537-546. 

From the pearl oyster Pinctada martensii, a glycosylceramide was isolated in which —80% of the fatty acids are comprised of a-hydroxy acids, and the main, long-chain base is CI9 , sphingosine.127... 

Sphingomyelin (SPH) is the major representative of the sphingophospholipids. This phospholipid consists of a ceramide unit, containing a fatty acid linked by an amide bond to the amine group of a long-chain base called sphingosine, linked at position 1 to phosphorylcholine (Fig. 1). It is a major component of animal complex lipids, but is not present in plants or microorganisms. 

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. 

Fatty acids and sphingosines. The lipid composition of the four monosialogangliosides is shown in Table II. The major fatty acids are palmitic, stearic and oleic acids. The long chain base is composed mainly of C-18 sphingosine with less than 20% of dihydrosphingosine. 

FATTY ACIDS AND LONG CHAIN BASES OF CHICKEN MUSCLE MONOSIALOGANGLIOSIDES... 

The backbone structure of the sphingolipids found in mammalian cells is the long-chain base, sphingosine. The latter is an 18-carbon moiety comprised of an aminoethanol residue at C-l (OH) and C-2 (NH2) with an allylic hydroxyl at C-3. Another name for sphingosine is D-erythro-2-amino-octadec-4-ene-l,3-diol. The latter compound is often referred to as sphingenine by many investigators. 

Karlsson, K.-A. (1970) Sphingolipid long chain bases, Lipids 5, 878-889. 

Carter HE, Clemer WD, Lands WM, Muller KL, Tomizawa HH (1954) Biochemistry of the sphingolipides. VIII. Occurrence of a long chain base in plant phosphatides. J Biol Chem 206 613-623 Casiraghi G, Rassu G, Spanu P (1995) Stereoselective approaches to bioactive carbohydrates and alkaloids-with a focus on recent syntheses drawing from the chiral pool. Chem Rev 95 1677... 

Karlsson KA, Samuelsson BE, Steen GO (1968) Structure and function of sphi-nolipids. 1. Differences in sphingolipid long-chain base pattern between kidney cortex, medulla, and papillae. Acta Chem Scand 22 1361-1364... 

Chemical Structures of Sphingoid Long-Chain Bases and Their Glycosylated and Phosphoryl-ated Derivatives... 

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