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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.

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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