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Carbohydrate Research, 17 (1979) 141-147@ Elsevier Scientific Publishing Company, Amsterdam - Printed in The NetherlandsSYNTHESIS OF p-NITROPHENYL 2-O-a-D-MANNOPYRANOSYL-a-D-MANNOPYRANOSIDE AND p-NITROPHENYL 6-O-a-~-MANNOPYRANO-SYL-c.+D-MANNOPYRANOSIDECHERYL M. REICHJ~RT*Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48104 (U.S.A.)(Received March 22nd, 1979; accepted for publication, April 20th, 1979)ABSTRACTCrystalline 2-O-a-D-mannopyranosyl-p-D-mannopyranose octaacetate wassynthesized by condensation of tetra-0-acetyl-a-D-mannopyranosyl bromide (3)with 1,3,4,6-tetra-O-acetyl-P-D-mannopyranose. 6-O-or-D-Mannopyranosyl-u-D-man-nopyranoseoctaacetatewas preparedby condensationof 3 with 1,2,3,4-tetra-o-acetyl-6-O-trityl-a-D-mannopyranose. Fusion of each mannobiosyl o&acetate with p-nitrophenol was followed by deacetylation, to give the corresponding p-nitrophenyl(l-2)- and (1+6)-or-D-mannobioside.INTRODUCTIONEarly studies by Avery and co-workers19* established that simple sugars,normally nonantigenic, acquire carbohydrate-specific antigenicity when conjugatedto protein carriers. The p-nitrophenyl D-mannobiosidesnow described were reduced,and the amines were employed in the formation of mannobioside-protein conjugates;the conjugates serve as antigens for the induction of antibodies sharing the D-manno-pyranose-binding specificity3*4of a lectin, concanavalin A.RESULTS AND DISCUSSIONThe reaction sequence was so devisedthat condensation of the monosaccharideunits occurred with readily available starting-materials early in the synthesis of bothdisaccharides (see Schemes1 and 2). Using the reaction conditions of Bahl and co-workers5, 1,3,4,6-tetra-0-acetyl+D-mannopyranose (4, ref. 6) readily condensedwith 3 to afford 2-0-u-D-mannopyranosyl-/?-D-mannopyranose octaacetate (5).A procedure developedby Lonngren and Svenssonfor the synthesisof ~-O-/&D-galactopyranosyl-D-mannose’was adapted for the synthesis of 6-O-u-D-manno-pyranosyl-u-D-mannopyranoseoctaacetate (10) ( see Scheme 2). The detritylation*Present address: Laboratory of Pathology, National Cancer Institute, National Institutes of Health,Bethesda, Maryland 20205, U.S.A.142 C. M. REICHERTOH33+4 -CH20H / 6t-0.7Scheme 1step was incorporated into the condensation reaction of 1,2,3,4-tetra-0-acetyl-6-O-trityl-a-D-mannopyranose (9) with 3, to yield the corresponding (1+6)-or-D-manno-biose octaacetate (10) directly.A zinc chloride-catalyzed, high-temperature, fusion technique’ was employedfor the condensation of p-nitrophenol with the (l-+2)- and (1+6)-a-D-mannobioseoctaacetate. The p-nitrophenyl hepta-O-acetyl-(l-+2)- and -(l-+6)-a-D-manno-biosides were subsequently deacetylated, and the free glycosides characterized.Following reduction to the corresponding amine, the (l-+2)-u-D-mannobiosidehapten was separately conjugated to bovine serum albumin and keyhole limpethemocyanin via diazonium and phenyl isothiocyanate reactions4.2- AND 6-O-U-D-MANNOSYL-U-D-MANNOSIDES 143‘r3fQ -0Scheme 2EXPERIMENTALGeneral. - Melting points were determined with a Fisher-Johns apparatus.Optical rotations were determined with a Rudolph model 80 polarimeter. Evapora-tions were conducted in vacua at 35-40” in a Biichi Rotavapor. Compounds weredried by being kept for 3 to 6 h in a vacuum oven at 40-45”. Acid hydrolyses wereperformed in a Scientific Products module heater No. 2025. Elemental analysesweremade in duplicate

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