No abstract

The N-glycans from 27 "plant" foodstuffs, including one from a gymnospermic plant and one from a fungus, were prepared by a new procedure and examined by means of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). For several samples, glycan structures were additionally investigated by size-fractionation and reverse-phase high-performance liquid chromatography in conjunction with exoglycosidase digests and finally also (1)H-nuclear magnetic resonance spectroscopy. The glycans found ranged from the typical vacuolar "horseradish peroxidase" type and oligomannose to complex Le(a)-carrying structures. Though the common mushroom exclusively contained N-glycans of the oligomannosidic type, all plant foods contained mixtures of the above-mentioned types. Apple, asparagus, avocado, banana, carrot, celery, hazelnut, kiwi, onion, orange, pear, pignoli, strawberry, and walnut were particularly rich in Le(a)-carrying N-glycans. Although traces of Le(a)-containing structures were also present in almond, pistachio, potato, and tomato, no such glycans could be found in cauliflower. Coconut exhibited almost exclusively N-glycans containing only xylose but no fucose. Oligomannosidic N-glycans dominated in buckwheat and especially in the legume seeds mung bean, pea, peanut, and soybean. Papaya presented a unique set of hybrid type structures partially containing the Le(a) determinant. These results are not only compatible with the hypothesis that the carbohydrate structures are another potential source of immunological cross-reaction between different plant allergens, but they also demonstrate that the Le(a)-type structure is very widespread among plants.

The absolute con@uration of neutral monosaccharides, 2-acetamido-2-deoxy sugars, and uranic acids can be determined by capillary g.

No abstract

The N-linked carbohydrate chains of phospholipase A, from honeybee (Apis mellifera) were released from glycopeptides with peptide-N-glycanase A and reductively aminated with 2-aminopyridine. The fluorescent derivatives were separated by size-fractionation and reverse-phase HPLC, yielding 14 fractions. Structural analysis was accomplished by compositional and methylation analyses, by comparison of the HPLC elution patterns with reference oligosaccharides, by stepwise exoglycosidase digestions which were monitored by HPLC, and, where necessary, by 500-MHz 'H-NMR spectroscopy.Ten oligosaccharides consisted of mannose, N-acetylglucosamine and fucose al-6 and/or al-3 linked to the innermost N-acetylglucosamine. Four compounds, which comprised 10% of the oligosaccharide pool from phospholipase A2, contained a rarely found terminal element with Nacetylgalactosamine. The structures of the 14 N-glycans from honeybee phospholipase A2 can be arranged into the following three series :Manal -6 \ / /

The Sialic Acid World Table 1 Survey of Reported Structures of Naturally Occurring Members of the Sialic Acid Family-cont'd Name Abbreviation References5-N-Acetyl-8-O-acetyl-9-Olactyl-neuraminic acid Neu5,8Ac 2 9Lt 45 5-N-Acetyl-8-O-methylneuraminic acid Neu5Ac8Me 6,19,25,33,46 5-N-Acetyl-4-O-acetyl-8-Omethyl-neuraminic acid Neu4,5Ac 2 8Me 19 5-N-Acetyl-9-O-acetyl-8-Omethyl-neuraminic acid Neu5,9Ac 2 8Me 6,19,33,46 5-N-Acetyl-9-O-methylneuraminic acid Neu5Ac9Me 47 5-N-Acetyl-4-O-sulfoneuraminic acid Neu5Ac4S 48 5-N-Acetyl-8-O-sulfoneuraminic acid Neu5Ac8S 19,32,49,50 5-N-Acetyl-4-O-acetyl-8-Osulfo-neuraminic acid Neu4,5Ac 2 8S 19 5-N-Acetyl-9-O-phosphoneuraminic acid f,g Neu5Ac9P 51 5-N-Acetyl-2-deoxy-2,3didehydro-neuraminic acid g,h Neu2en5Ac 6,30,33,43,52-54 5-N-Acetyl-9-O-acetyl-2deoxy-2,3-didehydroneuraminic acid g Neu2en5,9Ac 2 55,56 5-N-Acetyl-2-deoxy-2,3didehydro-9-O-lactylneuraminic acid g Neu2en5Ac9Lt 55,565-N-Acetyl-2,7-anhydroneuraminic acid g,i

Abstract-The neutral exopolysaccharide EPS180 produced from sucrose by the glucansucrase GTF180 enzyme from Lactobacillus reuteri 180 was found to be a (1?3, 1?6)-a-D D-glucan, with no repeating units present. Based on linkage analysis, periodate oxidation, and 1D/2D 1 H and 13 C NMR spectroscopy of the intact EPS180, as well as MS and NMR analysis of oligosaccharides obtained by partial acid hydrolysis of EPS180, a composite model, that includes all identified structural features, was formulated as follows: Ó

Human Tamm-Horsfall glycoprotein has been purified from the urine of one male. The Asn-linked carbohydrate chains were enzymically released by peptide-N4-(N-acetyl-~-glucosaminyl)asparagine amidase F, and separated from the remaining protein by gel-permeation chromatography on BioGel P-100. Fractionation of the intact (sulfated) sialylated carbohydrate chains was achieved by a combination of three liquid-chromatographic techniques, namely, anion-exchange FPLC on QSepharose, amine-adsorption HPLC on Lichrospher-NH2, and high-pH anion-exchange chromatography on CarboPac PA1. In total, more than 1 SO carbohydrate-containing fractions were obtained, some of which still contained mixtures of oligosaccharides. The primary structure of 30 N-glycans, including 10 novel oligosaccharides, were determined by one-and two-dimensional 'H-NMR spectroscopy at 500 MHz or 600 MHz. The types of compounds identified range from non-fucosylated, monosialylated, diantennary to fucosylated, tetrasialylated, tetraantennary carbohydrate chains, possessing the following terminal structural elements :NeuSAccl2 -3GalP1!-4GlcNAcPI - \ .The largest GalNAc-containing compound has the following structure : GalNAcPl