<b>Gas-Liquid Chromatography of Trimethylsilyl Derivatives of Sugars and Related Substances</b>

Sweeley, Charles C.; Bentley, Ronald; Makita, Masami; Wells, William W.

doi:10.1021/ja00899a032

Cited by 2,355 publications

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“…The hydrolysates were then partitioned between chloroform and water. The aqueous phase was dried under N, and analysed both on TLC silicagel-coated plates (Merck) with chloroform/methanol (7 : 3, v/v) as solvent, and by gas chromatography (GC) of their trimethylsilyl (TMS) derivatives (Sweeley et al, 1963). Authentic standards of 3-0-methylrhamnose and 3,4-di-O-methylrhamnose were obtained from the hydrolysis of the already described GPLs (Lopez Marin et al, 1991).…”

Section: Miscellaneous Analytical Techniquesmentioning

confidence: 99%

Structures of the glycopeptidolipid antigens of Mycobacterium abscessus and Mycobacterium chelonae and possible chemical basis of the serological cross-reactions in the Mycobacterium fortuitum complex

et al. 1994

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Mycobacterium abscessus and Mycobacterium chelonae, two members of the Mycobacterium fortuitum complex, contain five major glycolipids. A combination of NMR spectroscopy, fast atom bombardment mass spectrometry and chemical degradation was used to elucidate their structures. All the compounds belong to the family of glycopeptidolipids. A 6-deoxy-a-~-talosyl unit, which may bear one or two acetyl groups, invariably occupies the site of glycosylation on the threonine residue in the various compounds. A 3,4-di-O-methyl-or 2,3,4-tri-O-methyl-a-~-rhamnosyl unit modifies the alaninol end of the diglycosylated molecules. Both species also contain a multiglycosylated compound consisting of a-L-rhamnosyl-(I -+ 2)-3,4-di-O-methyl-a-~-rhamnosyl linked to alaninol, which belongs to the class of new variants of glycopeptidolipids recently described. Using an ELISA, the latter glycolipid as well as the diglycosylated ones (not previously reported to be antigenic), were shown to react with the serum raised against the whole lipid antigens of M. chelonae. A comparative serologic study of the native and chemically modified glycopeptidolipid antigens allowed the identification of their epitope as the 3,4-di-O-methyl-a-~-rhamnosyl residue. Similar experiments conducted on the glycopeptidolipids isolated from the serologically cross-reacting species M. peregrinum led to the conclusion that the epitope identified in M. chelonae and M. abscessus was involved in the cross-reactions and demonstrated the existence of a second haptenic moiety in the glycolipids of M. peregrinum, the 3-O-methyl-a-~-rhamnosyl unit. In addition to this latter non-shared epitope, the recently described sulfated glycopeptidolipid antigen of M. peregrinum did not react with the M. chelonae serum, thus further explaining the difference in the seroreactivity within the complex.

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Section: Miscellaneous Analytical Techniquesmentioning

confidence: 99%

Structures of the glycopeptidolipid antigens of Mycobacterium abscessus and Mycobacterium chelonae and possible chemical basis of the serological cross-reactions in the Mycobacterium fortuitum complex

et al. 1994

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“…They were then derivatized to the Me3Si ethers [19] in 40 pl pyridine/bis(trimethylsilyl)-trifluoroacetamide (1 : 1, v/v) for 1 h at room temperature.…”

Section: Identification Of Sialic Acidsmentioning

confidence: 99%

Porcine submaxillary mucin contains α2→3‐ and α2→6‐linked N‐acetyl‐ and N‐glycolyl‐neuraminic acid

Savage

Koppen

Schiphorst

et al. 1986

European Journal of Biochemistry

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Four acidic trisaccharides have been obtained by alkaline borohydride reductive cleavage (8-elimination) of a fraction of porcine submaxillary mucin precipitating at 60 -75% ethanol. Their structures have been investigated using the techniques of methylation analysis involving gas-liquid chromatography/mass spectrometry along with high-resolution 'H-NMR analysis. Two of the four oligosaccharides, B1-B4, contain N-acetylneuraminic acid (NeuAc) while two contain N-glycolylneuraminic acid (NeuGc). The following structures are proposed for the acidic trisaccharide fraction: (Bl) NeuAca(2-+3)Gal~(l-+3)GalNAcol, (B2) NeuGca(2+3)Galj?(1+3)GalNAcol,These oligosaccharides were present in a molar ratio of 69: 22: 4: 5. Although oligosaccharide B4 has previously been found in porcine submaxillary much B1, B2 and B3 have not. Furthermore, oligosaccharide B2 is a novel structure.The oligosaccharide structures of porcine submaxillary mucin and their biosynthesis have been the subject of many investigations [l -91. Some questions have, however, remained unanswered. For instance, Rearick et al. [q have reported the characterization of porcine submaxillary P-galactoside a2 +3-sialyltransferase, to form the sequence NeuAca(2-t 3)-Galfl(1+3)GalNAc, although this structural element had not been reported in porcine submaxillary mucin (PSM). In addition, a study by Sherblom and Dahlin [lo] showing that both NeuAc and NeuGc were present in tumour cell glycoproteins, along with the report of Buscher et al. [l 11 on the biosynthesis of NeuGc in porcine submaxillary glands and the considerable controversy which has surrounded the oligosaccharide structures of PSM [3 -51 prompted a further investigation.The mucin was precipitated from porcine submaxillary gland extracts using a higher alcohol concentration than that employed by earlier investigators. Oligosaccharides were released by P-elimination, and their structures were determined by high-resolution 'H-NMR spectroscopy and methylation analysis. Four sialic-acid-containing trisaccharides, three of Correspondence to A. V. Savage, Department of Chemistry, University College, Galway, IrelandAbbreviations. GalNAcul, reduced N-acetylgalactosamine; NeuAc, N-acetylneuraminic acid; NeuGc, N-glycolylneuraminic acid; HPLC, high-pressure liquid chromatography; GLC-MS, gasliquid chromatography/mass spectrometry; PSM, porcine submaxillary mucin.Enzymes. P-Galactoside ct2-+3-sialyltransferase (EC 2.4.99.4); NeuAc : a-N-acetylgalactosaminide a 2 +6-sialyltransferase (EC 2.4.99.3); N-acetylneuraminate monooxygenase (EC 1.14.99.18). which had not previously been described in PSM and one of which is novel, were found. MATERIALS AND METHODS Isolation of oligosaccharidesMucin was isolated from porcine submaxillary glands according to de Salegui and Plonska [12] except that additional precipitates were obtained: following the removal of the 48 -54% and 54 -60% ethanol precipitates by centrifugation, the mucin solution was brought to 75% (v/v) ethanol, allowed to stand at 4°C for 16 hand centrifuged at 270...

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“…Ces risultats sont en accord avec les donnees de la litterature: ce reactif ne reagit que sur des hydroxyles peu encombres [19] et donne des resultats non reproductibles avec les sucres [18]. Par contre, l'action du trimethyl silylimidazole dans la pyridine [20], tout comme celle du reactif de Sweeley [21] (trimCthylchlorosilane et hexamtthyldisilazane dans la pyridine) donne lieu a une reaction rapide et totale; dans les deux cas, le produit forme ne prksente plus de bandes hydroxyles en infra rouge et par chromatographie dans le solvant C, un seul spot de R, 0,27 est observe.…”

Section: Mise Au Point D'une Technique De Jractionnernentunclassified

Separation et etude structurale des especes moleculaires de monomycolates et de dimycolates de alpha-d-trehalose presents chez Mycobacterium phlei

Promé¹,

Lacave²,

Ahibo‐Coffy³

et al. 1976

Eur J Biochem

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a-D-Trehalose present in Mycobacterium phleiMixtures of dimycolates of a-u-trehalose (cord factor) and monomycolates have been isolated from Mycohacterium phlei and separated as trimethylsilyl derivatives according to the polarity of the fatty acid residues. The free glycolipids can be recovered by mild hydrolysis. Silylation and desilylation reactions did not induce any isomerisation.The structure of these trehalose esters has been determined by using a series of reactions elaborated on synthetic acyl-sugar models. Free hydroxyl groups are transformed into tetrahydropyran ethers, deacylated by dimsyl sodium, methylated and the sugar derivatives are hydrolyzed. The O-methylsugars obtained contain a methyl ether group located at the position where the acyl group was present initially. Identification by gas chromatography of the 0-methyl-sugars thus allows the location of the fatty acid residues in the glycolipid. It has been demonstrated that no migration occurs.Two types of 6-monomycoloyl-a-~-trehalose have been isolated, differing by the nature of the mycolic acid residues. One of them, called MA, contains "a-phlei mycolic acid". The other one, called M,, contains "y-phlei mycolic acid" which is the ester of 2-eicosanol with the co-carboxyl function of a dicarboxylic mycolic acid.

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Gas-Liquid Chromatography of Trimethylsilyl Derivatives of Sugars and Related Substances

Cited by 2,355 publications

References 0 publications

Structures of the glycopeptidolipid antigens of Mycobacterium abscessus and Mycobacterium chelonae and possible chemical basis of the serological cross-reactions in the Mycobacterium fortuitum complex

Structures of the glycopeptidolipid antigens of Mycobacterium abscessus and Mycobacterium chelonae and possible chemical basis of the serological cross-reactions in the Mycobacterium fortuitum complex

Porcine submaxillary mucin contains α2→3‐ and α2→6‐linked N‐acetyl‐ and N‐glycolyl‐neuraminic acid

Separation et etude structurale des especes moleculaires de monomycolates et de dimycolates de alpha-d-trehalose presents chez Mycobacterium phlei

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